Pressure Frying At Home - Some Basics
Oct 27, 2020 18:28:40 GMT
Ken_Griffiths, ThePieMan, and 2 more like this
Post by jwoz on Oct 27, 2020 18:28:40 GMT
Here is the thing about pressure frying at home: Nobody is going to tell you that you should pressure fry at home, and if they are willing to give you any instructions at all then they are going to tell you that, if you choose to follow their instructions, then that is your own choice and you do so at your own risk.
I’m telling you that myself right here, right now. If you burn hour house down or blow something up or get hurt or hurt someone else, then I am not responsible and these forums are not responsible – you are. There are risks associated with pressure frying, no matter how you do it, and you need to make your own choices about whether or not to assume those risks.
You should also be aware that not a single maker of pressure cookers that sells them in the U.S advises that their pressure cookers can be used for frying. In fact, all manufacturers that I am aware of explicitly say that you should not use their cookers for frying. If you do so, you are going against the advice of the manufacturer. (Just to be clear at the outset, when I refer to “pressure cookers” in this posting I am referring to standalone pressure cooker pots for stovetop use, and not the more elaborate all-in-one pressure fryer devices made by Kumora, Chicken Express, etc. that cost between $1K and $2K U.S. and that are specifically intended for pressure frying at around 8 psi in a small restaurant environment, but that some people have for home use (see Glen & Friends KFC series on YouTube for example.))
That should be warning enough for you, so now I can go ahead and express some personal views about pressure frying and provide you with an example of how I pressure fry great chicken at home.
When I first wanted to start pressure frying at home, I was very frustrated that I could not find a guide online. I remember thinking: “For goodness sake, somebody just tell me what *you* do and how and why you do it. I’m a big boy. I can make the risk assessment myself, but I’d rather not reinvent the wheel.” Maybe such a guide exists somewhere on the internet, but I never found it. I had to piece things together from many sources.
So I started researching pressure frying and how to do it relatively safely at home. That doesn’t make me an expert – I’m not – and there are people on these forums that know considerably more than I do about pressure frying. I’m just the one who was willing to write this.
The main point of this guide is to help you understand some basics about pressure frying and some of the safety issues involved. I think this is important because if you know how something works and where the risks come from, then you can more intelligently manage those risks and make your own decisions. I am also going to discuss a bit about the technique I use to pressure fry, but that’s not the main point of this post – this post is focused more on pressure fryers and considerations around using them rather than on the specific technique one uses when pressure frying. This may disappoint some, but there is good information about pressure frying techniques elsewhere. For example, if you want more detail regarding technique you can start with Ken’s posting on this thread:
kfc11.proboards.com/thread/496/pressure-frying-guides
Right up front I’m going to discuss a few aspects of pressure frying in general – mainly what happens to the chicken when you pressure fry it. Then I’m going to tell you *what* I use to pressure fry at home, so we can get that out of the way. After that I’m going to tell you *why* I use what I use, which is going to be interwoven with a discussion of some safety considerations. And finally, I will briefly talk about *how* I pressure fry, step by step.
I believe that what I am saying here is 99% true (no guarantees of even that). By “99% true” I mean that if you think of a bell curve/normal distribution, then I believe that what I am saying falls within the fat part of the bell curve. But to avoid writing a textbook I’m simplifying some things, and I’m not going to go into great detail about possible exceptions to various rules, various edge cases, etc. This post is just intended to give you some basic information that you can supplement with your own further research and inquiries.
PRESSURE FRYING IN GENERAL
What happens inside a pressure cooker is actually pretty interesting.
The point of an ordinary pressure cooker is to place water under pressure which increases the boiling point of that water. Among other things, this increase in temperature lets you cook items faster. If you want to cook (say) cabbage in water in a covered pot on the stove, then when that water gets to the boiling point – 212F/100C - it turns into steam. The cooking time of the cabbage is a function of, and is limited by, the boiling point of the cooking water.
If you put cabbage in a pressure cooker, though, and if that pressure cooker is set to 15psi, then this pressure lets the water get to about 250F/121C before it boils. Your cabbage will cook much faster at 250F/121C than at 212F/100C.
The same thing is true of chicken. Keep in mind that with respect to most items that people cook, there is water within the item itself. There is a lot of water in chicken. If you fry your chicken submerged in oil in an open pan, then (simplified) the water in the chicken heats up, turns into steam at its boiling point, comes into contact with the oil and escapes. (Just look at your pan when you are frying chicken and you will see this happening.) In an unpressurized environment, the water in the chicken will never get above 212F/100C - the boiling point of water.
If you apply pressure to the pot then you increase the boiling point of the water inside the chicken. Obviously, if the water in the chicken can get to 240F instead of 212F, then the chicken will cook faster due to the higher temperature, and it will lose less water in the process. That makes for both faster cooking times and moister chicken. Less water hitting the oil will make the oil last longer. And because the chicken is cooking “from the inside” more quickly due to the increased water temperature, the pressure cooker can be throttled to a lower temperature than a stovetop which can help preserve flavor.
As a jumping off point, it is important to understand that when you are pressure frying, the pressure is created by the *water* in the chicken that is reaching its boiling point then turning to steam. This steam builds up pressure in the pot and, when the desired pressure is reached, it eventually escapes through the pressure relief valve.
Water changes to steam. Oil doesn’t. So in both a pressure cooker and a pressure fryer the vapor that is coming out of the relief valve is steam from water. The only situation where you should ever see oil being blown out of the pot is in the event of a very sudden and uncontrolled release of pressure where the steam release would be so violent that it carried some oil with it.
MY EQUIPMENT
I’ll say this once here and won’t repeat it throughout: Many people pressure fry at home using many different techniques and many different types of equipment (a few of which alternatives will be discussed briefly in passing below), so please understand that the equipment and technique I discuss below represents just one possible way to approach this. There are many paths to the same destination. The point here is to show you at least one path in a level of detail sufficient for you to understand what one person does, and why he does it. The way I pressure fry isn’t the only way or even necessarily the best way. It is just one way. You don’t need the specific equipment that I use. For example, I use a portable induction cooktop for reasons I discuss below, but many others use regular stoves. They both work when used properly. My intent below – and what I will spend quite a few words on – is to tell you *why* I use what I use so that, to the extent you deem relevant, you can incorporate some of those considerations into whatever you decide to do.
So, with respect to *what* I use –
I use this pressure cooker for pressure frying:
www.amazon.com/gp/product/B00HYB5Z1M/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
(Amazon links can be weird, but this should pull up the 8 quart Magefesa Star R pressure cooker.)
This pressure cooker is stainless steel so it can be used with an induction cooktop.
I use a portable induction cooktop that is similar to this one:
www.amazon.com/Portable-Induction-Cooktop-Countertop-BT-180G3/dp/B0045QEPYM/ref=redir_mobile_desktop?ie=UTF8&aaxitk=-zcv9NZiyQd.sDxz0ntV5Q&hsa_cr_id=4897538310701&ref_=sbx_be_s_sparkle_mcd_asin_0
(This link should pull up a product called “Duxtop 1800W Portable Induction Cooktop Countertop Burner, Gold 8100MC/BT-180G3”.) A very important attribute of this cooktop is that you can set it to a specific temperature (not just a “power” setting”) where the cooktop senses the temperature of the pot that it sitting on it.
I use the following waterproof, heat resistant temperature probe:
www.thermoworks.com/TX-1002X-NP
This probe can be used in hot liquids, such as oil, and has a silicone insulated cable that can withstand 500F (260C) temperatures.
This is only a probe, so one needs a thermometer to go with it. Any number of Thermoworks thermometers, some reasonably priced, will work with this probe, but for the sake of completeness I will say that I use this particular thermometer with this probe:
www.thermoworks.com/Signals
This thermometer is obviously overkill for pressure frying, but I had it on hand for smoking meats, so I use it here as well. Like I said, though, I think you can use any number of Thermoworks thermometers with the indicated probe, including this one, I believe, which is far more economical:
www.thermoworks.com/DOT
If you wanted to confirm that this particular thermometer will work with this particular probe, you could easily contact Thermoworks and ask (they are a fantastic company).
I also use a pair of extra long kitchen tongs like these:
www.amazon.com/KingTong-Stainless-Steel-Tongs-Grill/dp/B07DBPL435/ref=sr_1_1?dchild=1&keywords=long+kitchen+tongs&qid=1603474204&s=home-garden&sr=1-1
And I use some wire racks (for transporting the chicken to and from the cooker), a half sheet pan, and some hot pads. That’s pretty much it.
So now that the “what” is out of the way, here is the “why,” which will be followed by the “how.”
The “why” will be interspersed with a discussion of some safety issues, because lots of the “why” is dictated by safety considerations.
I’m going to go ahead and reference a few safety concerns here briefly because they flow through the remaining discussion in various ways. When I refer to “pressure cooking” I am generally referring to using water in a pressure cooker in order to cook food or to preserve/can items. When I refer to “pressure frying” I am referring to using oil in a pressurized pot in order to fry food.
Although they are the same vessel, when I refer to a “pressure cooker” I am referring to a pressurized pot that is being used at that moment for pressure cooking, and when I refer to a “pressure fryer” I am referring to a pressurized pot that is being used at that moment for pressure frying.
When you think through the safety concerns, you realize that many of these concerns are common to both pressure cookers and pressure fryers, but there are some special concerns with pressure fryers. Below I will walk through some of these, listing a few Special Concerns with pressure fryers, and briefly indicating how I deal with these.
• Both pressure cookers and pressure fryers get hot and vent steam
o Either can burn you
To avoid this, you have to carefully vent the steam at the end of the cooking cycle
• Special Concern – At the end of a pressure *cooking* cycle – for example, when I am canning/preserving vegetables – the protocol is to let the pressure cooker sit until it has cooled and the pressure has subsided, which can take quite a while
• You can’t do this while pressure frying because at the end of the cooking cycle you need to vent the steam in the pressure fryer quickly to keep the food from absorbing too much oil
• I use my extra long kitchen tongs to gently raise the main pressure relief valve at the end of cooking in order to vent the steam, being careful to not be so forceful as to dislodge the valve entirely
• Both pressure cookers and pressure fryers operate under pressure and could explode
o Pressure cookers are engineered not to explode and they have various safety mechanisms to prevent this
Special Concern – the oil in a pressure fryer will get hotter than the water in a pressure cooker, so theoretically this could put extra stress on the pot and be more likely to weaken it, making it more susceptible to structural failure, but pots are generally designed to operate at much higher heat than one should be using to fry chicken so this is not a big concern of mine
• If there is an “overpressure situation” where the pot suddenly vents in an uncontrolled manner, then this could create a dangerous situation
o In both cases, you could get burned by the venting
Special Concern – if a pressure fryer suddenly vents, oil could be carried out of the cooker along with the steam which could do two things – it could burn you more than water would (it would be hotter and stickier than water), or it could hit a flame and ignite
• I address this by: (i) cleaning my pressure cooker lid and pressure relief valve with soap and water every time after use, and running water through the hole in the lid and the valve to make sure they are clear; (ii) using an induction cooktop so that if I were to find myself in this very unlikely scenario there would be no flame to ignite the oil; (iii) cooking outside of my main house (I have a work room just off the kitchen where I can plug in my induction cooktop)
• I note that the pressure cooker I use gets up to about 8 psi, whereas the KFC patent recited 15 psi, and current commercial pressure fryers seem to operate in the range of 12 to 14 psi. I would be open to using a higher pressure cooker, although I don’t think the higher pressure would significantly affect the taste of the chicken (I certainly don’t think the 4 to 7 pounds of extra pressure would be the difference in a recipe matching the OR or not), but I have not yet found a cooker that reaches a higher psi and that meets my personal safety criteria.
• There is no direct way to measure the temperature of the liquid inside the pressure cooker – this is not an issue when using water, because water changes its “state of matter” from liquid to vapor/steam at 212F (100C) and pressure cookers are calibrated to create a particular amount of pressure before venting
o Special Concern – For me, this is the biggest “special concern” of all – which is that you have to be very careful to not get your oil too hot because very bad things could happen if you do.
It is incredibly important for you to understand the following: Even if your pressure cooker has a gauge on it that purports to show temperature, if you are pressure frying then this gauge is *NOT* measuring the temperature of the oil in the cooker. This gauge is really just a pressure gauge, and the “temperature” it shows is based on the known fact that at certain pressures, at sea level, the water in the pot will boil at specific temperatures. For example, the temperature gauge will read 250F when the cooker reaches 15 psi because it is a fact that at sea level water boils at 250F when it is under 15 psi of pressure. This has almost nothing to do with the oil temperature. The oil temperature could be 260F, 480F or 500F and the pressure cooker temperature gauge could read 250F or less. (Think of it this way, as an oversimplified example: If you heated up your oil to 400F and there was no water at all in the pot, then there would be virtually no vapor produced, so the pressure gauge could read close to zero, which is inaccurate, and then if you were to introduce enough water into the pot to reach 15psi the gauge would read 250F, which is also inaccurate.) I am unaware of any pressure cooker that provides a way to directly measure the temperature of the liquid it contains (one would need a thermowell/temperature probe at the level of the liquid/oil), although I have seen a few that have been retrofitted to do this on an aftermarket basis (dangerous to do on a pressure vessel unless done and tested by a true professional). That’s why I use a separate thermometer to measure the temperature of my oil, as described below
I’m not going to write a treatise about how oil behaves at high temperatures, but you should understand a few terms:
• Smoke Point is the temperature at which oil starts to produce a continuous smoke (it doesn’t catch on fire at this temperature, it just starts to smoke, and this pretty much ruins the oil for cooking purposes)
• Flash Point is the lowest temperature at which oil produces sufficient vapors such that those vapors could be ignited by an *external* source (if your oil was at the flash point in a cast iron skillet, and you struck a match over your skillet, it would start a fire)
• Ignition Temperature is the lowest temperature at which the oil will burst into flames on its own without any external ignition source being needed
As an example, the smoke point, flash point and ignition temperature of cottonseed oil are around 420F, 610F and 650F (215C, 320C and 343C), respectively (you need to learn these values for whatever oil you are using)
o You should never approach any of these temperatures when cooking your chicken, which you should be dropping at a much lower temperature than the smoke point
I don’t view the smoke point as being dangerous – except to the taste of your chicken – and while obviously you don’t want to hit the smoke point, you absolutely, positively never ever want to hit the flash point or ignition temperature
o That is why I use an induction cooktop that can be set to specific temperatures and why I also use an external thermometer to monitor the temperature of the oil as I heat it up initially, as I re-heat it between batches, and as I pull out the chicken (as a crosscheck in the unlikely event that my induction cooktop were to go wild while heating up the pot, I would have a separate temperature probe and thermometer in the oil that would alert me)
As someone whose parents had a kitchen fire when he was growing up due to my mother leaving a cast iron skillet containing oil on a burner and then forgetting about it until it hit the ignition temperature (at which point we evacuated the house and called the fire department), I am aware of the need to be mindful of the potential for operator error here, but this is a possibility when you are open frying too, and it is easily managed if you stay sober and don’t do anything that is completely foolish
• I will talk about this in more detail below
That being said, WHY do I use the particular pressure cooker/fryer that I referenced above?
As others have pointed out, this pressure cooker used to be marketed as a pressure fryer in Europe. (Actually, there have been some changes in brands, corporate reorganizations and the like which I am not going to get into here, but the essential truth, as far as I have been able to tell, is that this model has remained the same - virtually identical to previous iterations of this cooker that were sold as pressure fryers in Europe.) You can see this article for more information: www.seriouseats.com/2013/08/gadgets-magefesa-star-pressure-cooker-fryer-review.html
What is good about this model? Well, as discussed in detail above, the heat of oil in the pot will be higher than the temperature of water, and pressure cookers are generally designed to work with water. So if you have a pressure cooker whose components were only designed to withstand 250F (120C) temperatures and you use it for pressure frying then you could have a problem.
I generally don’t view the metal components as being a big risk of failure here. Pots such as pressure cookers are regularly placed on powerful gas stoves and the heat is blasted under them, and the metal of those pots has to be designed to withstand those temperatures. Therefore, I don’t worry much about the fact that the temperature of the contents of the pressure cooker may be 50% higher than the water they would normally hold. I’m not concerned about the metal components of the pots melting or failing at these relatively moderate temperatures.
They could, of course, just like you could be driving down the road and suddenly your car’s steering could break and send you flying off into the woods, or something could break in an airplane and send it falling out of the sky. But those types of catastrophic and unforeseen accidents can happen with anything. Thankfully, with modern manufacturing techniques, quality control, etc., those types of failures are very unlikely, which is why we continue to drive cars and fly in airplanes. In discussing risks of pressure frying I am not addressing those types of inherent risks of doing anything. I am only focusing on the types of risks that are caused or heightened by virtue of using oil instead of water in a pressurized cooker.
In my view, the components of pressure cookers that are more prone to failure at high heat are those that are made out of rubber or plastic. That’s why I would never use a vintage pressure cooker as a pressure fryer. Older pressure cookers often used rubber as their gaskets (the gasket is the flexible ring that sits between the top and bottom of most cookers and helps seal the pot) and that rubber very well may not be able to withstand the increased heat that is generated by frying with oil. I would make sure that any cooker I was thinking about using had a silicone gasket that was capable of withstanding temperatures in the range of 500F (260C).
In my view, there are two considerations here. The first is the fact that hot oil itself could come into contact with the gasket or some other plastic or rubber part and it could compromise that part. This should not happen because if you are using the cooker properly oil really should never come into contact with the gasket, but if this did happen then it could melt the gasket which could lead to pressure suddenly and violently escaping from the cooker. The second consideration is that I believe the cooker itself will get hotter during frying than if you were just pressure cooking with water. It stands to reason that if you have oil in your pot and heat it to 400F and hold it there for an hour, the pot itself will get hotter than if you heated water to 250F and held it in the same pot for an hour. Of course, that higher heat could be problematic for a part that was not designed to withstand 400F temperatures.
Every pressure cooker that I am familiar with has redundant safety mechanisms. They have what I’ll call the “main” pressure relief valve (the one that is supposed to jiggle and let steam escape while you are cooking), an “emergency” relief valve (a separate valve that will open if the pressure of the cooker reaches a level much higher than anticipated – for example, if the main relief valve were to get blocked), and they often have some third redundant active or passive way of venting pressure in an “overpressure” situation.
I chose my pressure cooker because it has several redundant safety features and all of those are based on metal and not plastic or rubber. The “standard” pressure relief valve is metal, and the “emergency” relief valve is also metal. In addition, the lid has a crossbar across the top so that if an overpressure situation did develop – meaning that both the standard and emergency pressure relief valves failed, which is almost unfathomable – two things would be the case: The top of the cooker would not blow off and become a projectile because it is held down by the crossbar, and the lid of the pressure cooker would instead start to deform which would let steam escape out of the side before any kind of explosion occurred.
To me, the fact that my pressure cooker has metal valves vs. plastic or rubber valves is important. I have a number of other pressure cookers on hand that I will not use for frying chicken. Some are expensive “All American” aluminum pressure cookers. The “emergency relief valve” on those cookers is a rubber overpressure plug. I have no idea whether that plug would withstand the higher temperatures of frying, so when All American says you absolutely should not use their pressure cookers for frying, I believe them. Bottom line: If you are interested in using a pressure cooker as a pressure fryer, and if you don’t want to use the model I use, it is in my view advisable to make sure at a bare minimum that your cooker has a silicone gasket and it does not use anything, such as rubber or plastic, in any critical component that could be affected by the higher temperatures of frying.
From a process standpoint, you should also understand that you should only be using enough oil to cover the chicken that you are cooking by about an inch (2.5cm), and with the pressure cooker I referenced you will only be cooking about the equivalent of 2 to 3 medium sized chicken breasts at a time. It is almost unbelievable to me, but I have seen people who think that they need to fill the cooker up to the top with oil, which is absolutely wrong. If you do that, then the oil undoubtedly will come into contact with the gasket and possibly even the top of the cooker, and that could lead to very bad things. When I am cooking chicken, after I add the chicken to the pot, the oil remains a long distance from the top of the pot, and certainly well below the maximum fill line (I’ll give you specific quantities below). Your oil, after you add chicken, should stay a very good distance away from the top of your fryer.
WHAT IS MY PROCESS?
This section is going to be brief, but I’ll give you an overview of what I do. (Keep in mind that this is what I currently do – like others, I am continually tweaking my process – but this process makes great chicken so I’m not fundamentally unhappy with it.)
As I mentioned above, I do my frying in a workroom that is right off my kitchen but detached from my main house. I am always checking the cooker during the process, but I do go back and forth between the cooking area and the kitchen, so I am not constantly standing over the pot. I have a fire extinguisher in my kitchen that works with oil/grease fires. I had this on hand prior to starting pressure frying, and I think this is simply good practice – both having a fire extinguisher on hand and keeping it several feet away from the most likely location of a fire, so that an actual fire would not impede your ability to get to the extinguisher.
To start the process, I put 88 ounces (2.6 liters) of oil into my cooker. I leave the top of the cooker off. I set my induction cooktop to 360F/182C, and I begin to heat the oil. This 88 ounces is not a magic number. I generally use a mixture of cottonseed oil and corn oil, and the cottonseed oil I use comes in a 48 ounce container while the corn oil I use comes in a 40 ounce container. When I use one container of each, I get 88 ounces total. Since I started using this amount of oil early on, I just stuck with it because it is easy for me to measure. (I will note that the amount of oil I use is more aggressive than some, but it is what I have worked out with my process. It covers all the chicken I cook in my batches and it gives me the temperature drop/ramp that I want and the frying results that I am looking for. You can use less oil if you want, but that would affect cooking times, temperatures, etc. In my view, when experimenting, consistency is important and I don't want the amount of oil that I am using to be a variable, so I use the same amount every time and I also make sure that the weight of chicken in each of my batches is generally consistent. As one of your first experiments you may want to figure out your own oil amount and then stick with it.)
I rest my long tongs across the top of the pot. The temperature probe for my thermometer has a flexible metal cable that can be bent. I lightly crimp it so that the temperature probe goes into the oil but stops short of the bottom of the pot. My particular thermometer works over WiFi and will send an alert to my phone when a specific temperature is reached, and I have it set to alarm me when the temperature of the oil reaches 355F. During the entire cooking process I make sure that the pot is centered on the induction cooktop because if it is considerably out of center then it will be slow to heat up. I normally heat my pot up slowly while I am doing other things so the temperature of the oil is uniform throughout, but if I have to heat it up more quickly then I will make sure to stir the oil a few times while heating in order to assure a uniform temperature, which I will confirm with my thermometer.
Once the oil temperature reaches 355F, I bread my chicken and take it to the fryer.
With the specific induction cooktop that I use, the oil will probably not be at exactly 360F when I get to it with the chicken. It is normally below 360F. That’s because the cooktop’s logic function is very afraid of overshooting the set temperature, so as it approaches that temperature it starts to cycle on and off to avoid an overshoot, but that normally results in the set temperature not being achieved. Therefore, when I get to the cooker with the chicken I expect to have to set the cooktop to a higher temperature setting for about a minute in order to get the oil to 360F.
Once that happens I reset the temperature of the cooktop to 360, then I drop in the chicken pieces gently, one at a time, several seconds apart. Once the last piece is in, I set a timer for 90 seconds. Once 60 seconds have elapsed, I use my long tongs to gently turn the chicken pieces to make sure that they are not stuck together and to make sure that they are able to move freely in the pot. You can take another temperature reading at this time if you want.
When the 90 seconds have elapsed, I put the lid on the cooker and screw it down tight. The lid can be tricky, so sometimes before screwing it down I have to move it around a bit before I am confident that it is seated properly. If it is not seated properly, then steam will escape from around the lid instead of through the pressure relief valve and this will give you the same results as if you were to open fry the chicken (yes, I found this out through experience).
Once I believe I have the lid attached, I gently and very quickly flick the pressure relief valve with my finger to make sure that pressure is building up in the pot and not escaping from around the lid. If the pressure relief valve hisses and I don’t see any steam coming from around the lid, then I assume that the lid is seated correctly and I proceed accordingly.
I set a timer for 10 minutes and I start the timer. I leave the cooktop’s temperature set at 360F until the first steam escapes on its own from the pressure relief valve (until the valve starts to jiggle), then I turn the heat down to 320F. How long it takes for the first steam to escape depends on what type of chicken you are frying, etc., but it normally occurs at either 1 or 2 minutes after I first put the chicken into the fryer, at which point, just to be entirely clear, there will be between 8 and 9 minutes left on the cooking timer.
Of course, the temperatures on the induction cooktop don’t match the actual temperatures in the pot. Well, the first one does – the oil really is at 360F when I first drop in the chicken, but the relatively cold chicken plunges the oil temperature to around 320F or even 310F, depending on a few variables including the weight of the chicken in that particular batch. At the end of the cooking, although the temperature on the induction cooktop is set to 320F, the actual temperature of the oil will be around 280F-290F.
This is what I personally want. I don’t want to be cooking at 360F for the whole time. I want to be cooking at lower temperatures for a slightly longer period of time, because I believe that overly hot temperatures risk attenuating the herb and spice flavor. There are many takes on frying techniques – whether to immediately cap the cooker, whether to fry at higher or lower temperatures, etc. Discussing the pros and cons of each of those is beyond the scope of this post. You will see that Ken, in the post that I linked above, fries his chicken at a somewhat higher temperature than I do. The good news is that you can easily experiment with all of this. Do one batch one way, and another batch another way. I always do at least three batches of chicken every time I cook and I always vary the batches to see what works best. You can do that too. You can do several variations during the same cooking cycle. Just make sure to stay focused on the safety issues.
Those who cook on non-induction cooktops – whether electric or gas – invariably get their oil up to a stable temperature of their choosing, drop their chicken into the oil, then reduce the heat when they cap the cooker. That makes sense. If you have a cooktop that is set to a level of heat that gets your oil to a stable temperature of 360F but not above, then putting your chicken in will reduce the temperature of the oil, and if you then reduce the heat setting of your stove enough then it is unlikely to get the oil back up to 360F – and certainly shouldn’t get the oil up to the flash point – in the relatively brief time that you will be frying chicken. But if I were to use my cooker on a non-induction stove, I would definitely do some trials with an accurate thermometer until I knew exactly how much to reduce the heat and exactly what temperature increase I should expect in the pot after capping it. That would be important to me for the sake of safety and also for the sake of process repeatability. (I also have both an electric and a stovetop Chicken Bucket and back when I was using those more regularly I had the process worked out for those.)
Once my 10 minute timer has gone off, I use my long tongs and gently tilt the pressure relief valve, being careful not to remove it entirely. The steam escapes quickly – over about a 20 second period – and when it has almost all vented off I start to unscrew the lid. Sometimes I will gently toggle the pressure relief valve with my finger once or twice during the “unscrewing the lid” process in order to vent any remaining steam through the pressure relief valve.
I remove the pressure fryer lid and, using my tongs, I reach into the fryer and immediately remove the chicken and put it on an wire rack that is sitting on a half sheet pan (like a large cookie sheet with sides) that I then put in a steam oven to rest, like Ken does.
I will note that for a while I used a basket inside my pressure fryer. Although the exact basket that I have is no longer available, it looked like this, but I cut off the plastic/rubber leaving only bare metal:
www.amazon.com/kaviatek-B47D-Stainless-Accessories-Pressure/dp/B079CLQJ5Z/ref=sr_1_3?dchild=1&keywords=8+quart+pressure+cooker+basket&qid=1603488109&sr=8-3
I used this basket so I could pull all the chicken out of the oil immediately when I opened the cooker, and so I could see the chicken better in order to grab it with my tongs.
However, I have stopped using this basket for the time being because it added some awkwardness to the process, and even though the basket I have fits my cooker quite well, it still reduces the capacity of the cooker somewhat, so at the moment it isn’t clear to me that the benefits outweigh the detriments.
So that was quite a lengthy explanation, which was given with the hope that it will help others who come along in the future and keep them from having to put forth as much effort as I did in understanding the basics and learning how to do this (hopefully) safely. I have no doubt that others will have things to add and correct, but maybe this will give us a start.
I’m telling you that myself right here, right now. If you burn hour house down or blow something up or get hurt or hurt someone else, then I am not responsible and these forums are not responsible – you are. There are risks associated with pressure frying, no matter how you do it, and you need to make your own choices about whether or not to assume those risks.
You should also be aware that not a single maker of pressure cookers that sells them in the U.S advises that their pressure cookers can be used for frying. In fact, all manufacturers that I am aware of explicitly say that you should not use their cookers for frying. If you do so, you are going against the advice of the manufacturer. (Just to be clear at the outset, when I refer to “pressure cookers” in this posting I am referring to standalone pressure cooker pots for stovetop use, and not the more elaborate all-in-one pressure fryer devices made by Kumora, Chicken Express, etc. that cost between $1K and $2K U.S. and that are specifically intended for pressure frying at around 8 psi in a small restaurant environment, but that some people have for home use (see Glen & Friends KFC series on YouTube for example.))
That should be warning enough for you, so now I can go ahead and express some personal views about pressure frying and provide you with an example of how I pressure fry great chicken at home.
When I first wanted to start pressure frying at home, I was very frustrated that I could not find a guide online. I remember thinking: “For goodness sake, somebody just tell me what *you* do and how and why you do it. I’m a big boy. I can make the risk assessment myself, but I’d rather not reinvent the wheel.” Maybe such a guide exists somewhere on the internet, but I never found it. I had to piece things together from many sources.
So I started researching pressure frying and how to do it relatively safely at home. That doesn’t make me an expert – I’m not – and there are people on these forums that know considerably more than I do about pressure frying. I’m just the one who was willing to write this.
The main point of this guide is to help you understand some basics about pressure frying and some of the safety issues involved. I think this is important because if you know how something works and where the risks come from, then you can more intelligently manage those risks and make your own decisions. I am also going to discuss a bit about the technique I use to pressure fry, but that’s not the main point of this post – this post is focused more on pressure fryers and considerations around using them rather than on the specific technique one uses when pressure frying. This may disappoint some, but there is good information about pressure frying techniques elsewhere. For example, if you want more detail regarding technique you can start with Ken’s posting on this thread:
kfc11.proboards.com/thread/496/pressure-frying-guides
Right up front I’m going to discuss a few aspects of pressure frying in general – mainly what happens to the chicken when you pressure fry it. Then I’m going to tell you *what* I use to pressure fry at home, so we can get that out of the way. After that I’m going to tell you *why* I use what I use, which is going to be interwoven with a discussion of some safety considerations. And finally, I will briefly talk about *how* I pressure fry, step by step.
I believe that what I am saying here is 99% true (no guarantees of even that). By “99% true” I mean that if you think of a bell curve/normal distribution, then I believe that what I am saying falls within the fat part of the bell curve. But to avoid writing a textbook I’m simplifying some things, and I’m not going to go into great detail about possible exceptions to various rules, various edge cases, etc. This post is just intended to give you some basic information that you can supplement with your own further research and inquiries.
PRESSURE FRYING IN GENERAL
What happens inside a pressure cooker is actually pretty interesting.
The point of an ordinary pressure cooker is to place water under pressure which increases the boiling point of that water. Among other things, this increase in temperature lets you cook items faster. If you want to cook (say) cabbage in water in a covered pot on the stove, then when that water gets to the boiling point – 212F/100C - it turns into steam. The cooking time of the cabbage is a function of, and is limited by, the boiling point of the cooking water.
If you put cabbage in a pressure cooker, though, and if that pressure cooker is set to 15psi, then this pressure lets the water get to about 250F/121C before it boils. Your cabbage will cook much faster at 250F/121C than at 212F/100C.
The same thing is true of chicken. Keep in mind that with respect to most items that people cook, there is water within the item itself. There is a lot of water in chicken. If you fry your chicken submerged in oil in an open pan, then (simplified) the water in the chicken heats up, turns into steam at its boiling point, comes into contact with the oil and escapes. (Just look at your pan when you are frying chicken and you will see this happening.) In an unpressurized environment, the water in the chicken will never get above 212F/100C - the boiling point of water.
If you apply pressure to the pot then you increase the boiling point of the water inside the chicken. Obviously, if the water in the chicken can get to 240F instead of 212F, then the chicken will cook faster due to the higher temperature, and it will lose less water in the process. That makes for both faster cooking times and moister chicken. Less water hitting the oil will make the oil last longer. And because the chicken is cooking “from the inside” more quickly due to the increased water temperature, the pressure cooker can be throttled to a lower temperature than a stovetop which can help preserve flavor.
As a jumping off point, it is important to understand that when you are pressure frying, the pressure is created by the *water* in the chicken that is reaching its boiling point then turning to steam. This steam builds up pressure in the pot and, when the desired pressure is reached, it eventually escapes through the pressure relief valve.
Water changes to steam. Oil doesn’t. So in both a pressure cooker and a pressure fryer the vapor that is coming out of the relief valve is steam from water. The only situation where you should ever see oil being blown out of the pot is in the event of a very sudden and uncontrolled release of pressure where the steam release would be so violent that it carried some oil with it.
MY EQUIPMENT
I’ll say this once here and won’t repeat it throughout: Many people pressure fry at home using many different techniques and many different types of equipment (a few of which alternatives will be discussed briefly in passing below), so please understand that the equipment and technique I discuss below represents just one possible way to approach this. There are many paths to the same destination. The point here is to show you at least one path in a level of detail sufficient for you to understand what one person does, and why he does it. The way I pressure fry isn’t the only way or even necessarily the best way. It is just one way. You don’t need the specific equipment that I use. For example, I use a portable induction cooktop for reasons I discuss below, but many others use regular stoves. They both work when used properly. My intent below – and what I will spend quite a few words on – is to tell you *why* I use what I use so that, to the extent you deem relevant, you can incorporate some of those considerations into whatever you decide to do.
So, with respect to *what* I use –
I use this pressure cooker for pressure frying:
www.amazon.com/gp/product/B00HYB5Z1M/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
(Amazon links can be weird, but this should pull up the 8 quart Magefesa Star R pressure cooker.)
This pressure cooker is stainless steel so it can be used with an induction cooktop.
I use a portable induction cooktop that is similar to this one:
www.amazon.com/Portable-Induction-Cooktop-Countertop-BT-180G3/dp/B0045QEPYM/ref=redir_mobile_desktop?ie=UTF8&aaxitk=-zcv9NZiyQd.sDxz0ntV5Q&hsa_cr_id=4897538310701&ref_=sbx_be_s_sparkle_mcd_asin_0
(This link should pull up a product called “Duxtop 1800W Portable Induction Cooktop Countertop Burner, Gold 8100MC/BT-180G3”.) A very important attribute of this cooktop is that you can set it to a specific temperature (not just a “power” setting”) where the cooktop senses the temperature of the pot that it sitting on it.
I use the following waterproof, heat resistant temperature probe:
www.thermoworks.com/TX-1002X-NP
This probe can be used in hot liquids, such as oil, and has a silicone insulated cable that can withstand 500F (260C) temperatures.
This is only a probe, so one needs a thermometer to go with it. Any number of Thermoworks thermometers, some reasonably priced, will work with this probe, but for the sake of completeness I will say that I use this particular thermometer with this probe:
www.thermoworks.com/Signals
This thermometer is obviously overkill for pressure frying, but I had it on hand for smoking meats, so I use it here as well. Like I said, though, I think you can use any number of Thermoworks thermometers with the indicated probe, including this one, I believe, which is far more economical:
www.thermoworks.com/DOT
If you wanted to confirm that this particular thermometer will work with this particular probe, you could easily contact Thermoworks and ask (they are a fantastic company).
I also use a pair of extra long kitchen tongs like these:
www.amazon.com/KingTong-Stainless-Steel-Tongs-Grill/dp/B07DBPL435/ref=sr_1_1?dchild=1&keywords=long+kitchen+tongs&qid=1603474204&s=home-garden&sr=1-1
And I use some wire racks (for transporting the chicken to and from the cooker), a half sheet pan, and some hot pads. That’s pretty much it.
So now that the “what” is out of the way, here is the “why,” which will be followed by the “how.”
The “why” will be interspersed with a discussion of some safety issues, because lots of the “why” is dictated by safety considerations.
I’m going to go ahead and reference a few safety concerns here briefly because they flow through the remaining discussion in various ways. When I refer to “pressure cooking” I am generally referring to using water in a pressure cooker in order to cook food or to preserve/can items. When I refer to “pressure frying” I am referring to using oil in a pressurized pot in order to fry food.
Although they are the same vessel, when I refer to a “pressure cooker” I am referring to a pressurized pot that is being used at that moment for pressure cooking, and when I refer to a “pressure fryer” I am referring to a pressurized pot that is being used at that moment for pressure frying.
When you think through the safety concerns, you realize that many of these concerns are common to both pressure cookers and pressure fryers, but there are some special concerns with pressure fryers. Below I will walk through some of these, listing a few Special Concerns with pressure fryers, and briefly indicating how I deal with these.
• Both pressure cookers and pressure fryers get hot and vent steam
o Either can burn you
To avoid this, you have to carefully vent the steam at the end of the cooking cycle
• Special Concern – At the end of a pressure *cooking* cycle – for example, when I am canning/preserving vegetables – the protocol is to let the pressure cooker sit until it has cooled and the pressure has subsided, which can take quite a while
• You can’t do this while pressure frying because at the end of the cooking cycle you need to vent the steam in the pressure fryer quickly to keep the food from absorbing too much oil
• I use my extra long kitchen tongs to gently raise the main pressure relief valve at the end of cooking in order to vent the steam, being careful to not be so forceful as to dislodge the valve entirely
• Both pressure cookers and pressure fryers operate under pressure and could explode
o Pressure cookers are engineered not to explode and they have various safety mechanisms to prevent this
Special Concern – the oil in a pressure fryer will get hotter than the water in a pressure cooker, so theoretically this could put extra stress on the pot and be more likely to weaken it, making it more susceptible to structural failure, but pots are generally designed to operate at much higher heat than one should be using to fry chicken so this is not a big concern of mine
• If there is an “overpressure situation” where the pot suddenly vents in an uncontrolled manner, then this could create a dangerous situation
o In both cases, you could get burned by the venting
Special Concern – if a pressure fryer suddenly vents, oil could be carried out of the cooker along with the steam which could do two things – it could burn you more than water would (it would be hotter and stickier than water), or it could hit a flame and ignite
• I address this by: (i) cleaning my pressure cooker lid and pressure relief valve with soap and water every time after use, and running water through the hole in the lid and the valve to make sure they are clear; (ii) using an induction cooktop so that if I were to find myself in this very unlikely scenario there would be no flame to ignite the oil; (iii) cooking outside of my main house (I have a work room just off the kitchen where I can plug in my induction cooktop)
• I note that the pressure cooker I use gets up to about 8 psi, whereas the KFC patent recited 15 psi, and current commercial pressure fryers seem to operate in the range of 12 to 14 psi. I would be open to using a higher pressure cooker, although I don’t think the higher pressure would significantly affect the taste of the chicken (I certainly don’t think the 4 to 7 pounds of extra pressure would be the difference in a recipe matching the OR or not), but I have not yet found a cooker that reaches a higher psi and that meets my personal safety criteria.
• There is no direct way to measure the temperature of the liquid inside the pressure cooker – this is not an issue when using water, because water changes its “state of matter” from liquid to vapor/steam at 212F (100C) and pressure cookers are calibrated to create a particular amount of pressure before venting
o Special Concern – For me, this is the biggest “special concern” of all – which is that you have to be very careful to not get your oil too hot because very bad things could happen if you do.
It is incredibly important for you to understand the following: Even if your pressure cooker has a gauge on it that purports to show temperature, if you are pressure frying then this gauge is *NOT* measuring the temperature of the oil in the cooker. This gauge is really just a pressure gauge, and the “temperature” it shows is based on the known fact that at certain pressures, at sea level, the water in the pot will boil at specific temperatures. For example, the temperature gauge will read 250F when the cooker reaches 15 psi because it is a fact that at sea level water boils at 250F when it is under 15 psi of pressure. This has almost nothing to do with the oil temperature. The oil temperature could be 260F, 480F or 500F and the pressure cooker temperature gauge could read 250F or less. (Think of it this way, as an oversimplified example: If you heated up your oil to 400F and there was no water at all in the pot, then there would be virtually no vapor produced, so the pressure gauge could read close to zero, which is inaccurate, and then if you were to introduce enough water into the pot to reach 15psi the gauge would read 250F, which is also inaccurate.) I am unaware of any pressure cooker that provides a way to directly measure the temperature of the liquid it contains (one would need a thermowell/temperature probe at the level of the liquid/oil), although I have seen a few that have been retrofitted to do this on an aftermarket basis (dangerous to do on a pressure vessel unless done and tested by a true professional). That’s why I use a separate thermometer to measure the temperature of my oil, as described below
I’m not going to write a treatise about how oil behaves at high temperatures, but you should understand a few terms:
• Smoke Point is the temperature at which oil starts to produce a continuous smoke (it doesn’t catch on fire at this temperature, it just starts to smoke, and this pretty much ruins the oil for cooking purposes)
• Flash Point is the lowest temperature at which oil produces sufficient vapors such that those vapors could be ignited by an *external* source (if your oil was at the flash point in a cast iron skillet, and you struck a match over your skillet, it would start a fire)
• Ignition Temperature is the lowest temperature at which the oil will burst into flames on its own without any external ignition source being needed
As an example, the smoke point, flash point and ignition temperature of cottonseed oil are around 420F, 610F and 650F (215C, 320C and 343C), respectively (you need to learn these values for whatever oil you are using)
o You should never approach any of these temperatures when cooking your chicken, which you should be dropping at a much lower temperature than the smoke point
I don’t view the smoke point as being dangerous – except to the taste of your chicken – and while obviously you don’t want to hit the smoke point, you absolutely, positively never ever want to hit the flash point or ignition temperature
o That is why I use an induction cooktop that can be set to specific temperatures and why I also use an external thermometer to monitor the temperature of the oil as I heat it up initially, as I re-heat it between batches, and as I pull out the chicken (as a crosscheck in the unlikely event that my induction cooktop were to go wild while heating up the pot, I would have a separate temperature probe and thermometer in the oil that would alert me)
As someone whose parents had a kitchen fire when he was growing up due to my mother leaving a cast iron skillet containing oil on a burner and then forgetting about it until it hit the ignition temperature (at which point we evacuated the house and called the fire department), I am aware of the need to be mindful of the potential for operator error here, but this is a possibility when you are open frying too, and it is easily managed if you stay sober and don’t do anything that is completely foolish
• I will talk about this in more detail below
That being said, WHY do I use the particular pressure cooker/fryer that I referenced above?
As others have pointed out, this pressure cooker used to be marketed as a pressure fryer in Europe. (Actually, there have been some changes in brands, corporate reorganizations and the like which I am not going to get into here, but the essential truth, as far as I have been able to tell, is that this model has remained the same - virtually identical to previous iterations of this cooker that were sold as pressure fryers in Europe.) You can see this article for more information: www.seriouseats.com/2013/08/gadgets-magefesa-star-pressure-cooker-fryer-review.html
What is good about this model? Well, as discussed in detail above, the heat of oil in the pot will be higher than the temperature of water, and pressure cookers are generally designed to work with water. So if you have a pressure cooker whose components were only designed to withstand 250F (120C) temperatures and you use it for pressure frying then you could have a problem.
I generally don’t view the metal components as being a big risk of failure here. Pots such as pressure cookers are regularly placed on powerful gas stoves and the heat is blasted under them, and the metal of those pots has to be designed to withstand those temperatures. Therefore, I don’t worry much about the fact that the temperature of the contents of the pressure cooker may be 50% higher than the water they would normally hold. I’m not concerned about the metal components of the pots melting or failing at these relatively moderate temperatures.
They could, of course, just like you could be driving down the road and suddenly your car’s steering could break and send you flying off into the woods, or something could break in an airplane and send it falling out of the sky. But those types of catastrophic and unforeseen accidents can happen with anything. Thankfully, with modern manufacturing techniques, quality control, etc., those types of failures are very unlikely, which is why we continue to drive cars and fly in airplanes. In discussing risks of pressure frying I am not addressing those types of inherent risks of doing anything. I am only focusing on the types of risks that are caused or heightened by virtue of using oil instead of water in a pressurized cooker.
In my view, the components of pressure cookers that are more prone to failure at high heat are those that are made out of rubber or plastic. That’s why I would never use a vintage pressure cooker as a pressure fryer. Older pressure cookers often used rubber as their gaskets (the gasket is the flexible ring that sits between the top and bottom of most cookers and helps seal the pot) and that rubber very well may not be able to withstand the increased heat that is generated by frying with oil. I would make sure that any cooker I was thinking about using had a silicone gasket that was capable of withstanding temperatures in the range of 500F (260C).
In my view, there are two considerations here. The first is the fact that hot oil itself could come into contact with the gasket or some other plastic or rubber part and it could compromise that part. This should not happen because if you are using the cooker properly oil really should never come into contact with the gasket, but if this did happen then it could melt the gasket which could lead to pressure suddenly and violently escaping from the cooker. The second consideration is that I believe the cooker itself will get hotter during frying than if you were just pressure cooking with water. It stands to reason that if you have oil in your pot and heat it to 400F and hold it there for an hour, the pot itself will get hotter than if you heated water to 250F and held it in the same pot for an hour. Of course, that higher heat could be problematic for a part that was not designed to withstand 400F temperatures.
Every pressure cooker that I am familiar with has redundant safety mechanisms. They have what I’ll call the “main” pressure relief valve (the one that is supposed to jiggle and let steam escape while you are cooking), an “emergency” relief valve (a separate valve that will open if the pressure of the cooker reaches a level much higher than anticipated – for example, if the main relief valve were to get blocked), and they often have some third redundant active or passive way of venting pressure in an “overpressure” situation.
I chose my pressure cooker because it has several redundant safety features and all of those are based on metal and not plastic or rubber. The “standard” pressure relief valve is metal, and the “emergency” relief valve is also metal. In addition, the lid has a crossbar across the top so that if an overpressure situation did develop – meaning that both the standard and emergency pressure relief valves failed, which is almost unfathomable – two things would be the case: The top of the cooker would not blow off and become a projectile because it is held down by the crossbar, and the lid of the pressure cooker would instead start to deform which would let steam escape out of the side before any kind of explosion occurred.
To me, the fact that my pressure cooker has metal valves vs. plastic or rubber valves is important. I have a number of other pressure cookers on hand that I will not use for frying chicken. Some are expensive “All American” aluminum pressure cookers. The “emergency relief valve” on those cookers is a rubber overpressure plug. I have no idea whether that plug would withstand the higher temperatures of frying, so when All American says you absolutely should not use their pressure cookers for frying, I believe them. Bottom line: If you are interested in using a pressure cooker as a pressure fryer, and if you don’t want to use the model I use, it is in my view advisable to make sure at a bare minimum that your cooker has a silicone gasket and it does not use anything, such as rubber or plastic, in any critical component that could be affected by the higher temperatures of frying.
From a process standpoint, you should also understand that you should only be using enough oil to cover the chicken that you are cooking by about an inch (2.5cm), and with the pressure cooker I referenced you will only be cooking about the equivalent of 2 to 3 medium sized chicken breasts at a time. It is almost unbelievable to me, but I have seen people who think that they need to fill the cooker up to the top with oil, which is absolutely wrong. If you do that, then the oil undoubtedly will come into contact with the gasket and possibly even the top of the cooker, and that could lead to very bad things. When I am cooking chicken, after I add the chicken to the pot, the oil remains a long distance from the top of the pot, and certainly well below the maximum fill line (I’ll give you specific quantities below). Your oil, after you add chicken, should stay a very good distance away from the top of your fryer.
WHAT IS MY PROCESS?
This section is going to be brief, but I’ll give you an overview of what I do. (Keep in mind that this is what I currently do – like others, I am continually tweaking my process – but this process makes great chicken so I’m not fundamentally unhappy with it.)
As I mentioned above, I do my frying in a workroom that is right off my kitchen but detached from my main house. I am always checking the cooker during the process, but I do go back and forth between the cooking area and the kitchen, so I am not constantly standing over the pot. I have a fire extinguisher in my kitchen that works with oil/grease fires. I had this on hand prior to starting pressure frying, and I think this is simply good practice – both having a fire extinguisher on hand and keeping it several feet away from the most likely location of a fire, so that an actual fire would not impede your ability to get to the extinguisher.
To start the process, I put 88 ounces (2.6 liters) of oil into my cooker. I leave the top of the cooker off. I set my induction cooktop to 360F/182C, and I begin to heat the oil. This 88 ounces is not a magic number. I generally use a mixture of cottonseed oil and corn oil, and the cottonseed oil I use comes in a 48 ounce container while the corn oil I use comes in a 40 ounce container. When I use one container of each, I get 88 ounces total. Since I started using this amount of oil early on, I just stuck with it because it is easy for me to measure. (I will note that the amount of oil I use is more aggressive than some, but it is what I have worked out with my process. It covers all the chicken I cook in my batches and it gives me the temperature drop/ramp that I want and the frying results that I am looking for. You can use less oil if you want, but that would affect cooking times, temperatures, etc. In my view, when experimenting, consistency is important and I don't want the amount of oil that I am using to be a variable, so I use the same amount every time and I also make sure that the weight of chicken in each of my batches is generally consistent. As one of your first experiments you may want to figure out your own oil amount and then stick with it.)
I rest my long tongs across the top of the pot. The temperature probe for my thermometer has a flexible metal cable that can be bent. I lightly crimp it so that the temperature probe goes into the oil but stops short of the bottom of the pot. My particular thermometer works over WiFi and will send an alert to my phone when a specific temperature is reached, and I have it set to alarm me when the temperature of the oil reaches 355F. During the entire cooking process I make sure that the pot is centered on the induction cooktop because if it is considerably out of center then it will be slow to heat up. I normally heat my pot up slowly while I am doing other things so the temperature of the oil is uniform throughout, but if I have to heat it up more quickly then I will make sure to stir the oil a few times while heating in order to assure a uniform temperature, which I will confirm with my thermometer.
Once the oil temperature reaches 355F, I bread my chicken and take it to the fryer.
With the specific induction cooktop that I use, the oil will probably not be at exactly 360F when I get to it with the chicken. It is normally below 360F. That’s because the cooktop’s logic function is very afraid of overshooting the set temperature, so as it approaches that temperature it starts to cycle on and off to avoid an overshoot, but that normally results in the set temperature not being achieved. Therefore, when I get to the cooker with the chicken I expect to have to set the cooktop to a higher temperature setting for about a minute in order to get the oil to 360F.
Once that happens I reset the temperature of the cooktop to 360, then I drop in the chicken pieces gently, one at a time, several seconds apart. Once the last piece is in, I set a timer for 90 seconds. Once 60 seconds have elapsed, I use my long tongs to gently turn the chicken pieces to make sure that they are not stuck together and to make sure that they are able to move freely in the pot. You can take another temperature reading at this time if you want.
When the 90 seconds have elapsed, I put the lid on the cooker and screw it down tight. The lid can be tricky, so sometimes before screwing it down I have to move it around a bit before I am confident that it is seated properly. If it is not seated properly, then steam will escape from around the lid instead of through the pressure relief valve and this will give you the same results as if you were to open fry the chicken (yes, I found this out through experience).
Once I believe I have the lid attached, I gently and very quickly flick the pressure relief valve with my finger to make sure that pressure is building up in the pot and not escaping from around the lid. If the pressure relief valve hisses and I don’t see any steam coming from around the lid, then I assume that the lid is seated correctly and I proceed accordingly.
I set a timer for 10 minutes and I start the timer. I leave the cooktop’s temperature set at 360F until the first steam escapes on its own from the pressure relief valve (until the valve starts to jiggle), then I turn the heat down to 320F. How long it takes for the first steam to escape depends on what type of chicken you are frying, etc., but it normally occurs at either 1 or 2 minutes after I first put the chicken into the fryer, at which point, just to be entirely clear, there will be between 8 and 9 minutes left on the cooking timer.
Of course, the temperatures on the induction cooktop don’t match the actual temperatures in the pot. Well, the first one does – the oil really is at 360F when I first drop in the chicken, but the relatively cold chicken plunges the oil temperature to around 320F or even 310F, depending on a few variables including the weight of the chicken in that particular batch. At the end of the cooking, although the temperature on the induction cooktop is set to 320F, the actual temperature of the oil will be around 280F-290F.
This is what I personally want. I don’t want to be cooking at 360F for the whole time. I want to be cooking at lower temperatures for a slightly longer period of time, because I believe that overly hot temperatures risk attenuating the herb and spice flavor. There are many takes on frying techniques – whether to immediately cap the cooker, whether to fry at higher or lower temperatures, etc. Discussing the pros and cons of each of those is beyond the scope of this post. You will see that Ken, in the post that I linked above, fries his chicken at a somewhat higher temperature than I do. The good news is that you can easily experiment with all of this. Do one batch one way, and another batch another way. I always do at least three batches of chicken every time I cook and I always vary the batches to see what works best. You can do that too. You can do several variations during the same cooking cycle. Just make sure to stay focused on the safety issues.
Those who cook on non-induction cooktops – whether electric or gas – invariably get their oil up to a stable temperature of their choosing, drop their chicken into the oil, then reduce the heat when they cap the cooker. That makes sense. If you have a cooktop that is set to a level of heat that gets your oil to a stable temperature of 360F but not above, then putting your chicken in will reduce the temperature of the oil, and if you then reduce the heat setting of your stove enough then it is unlikely to get the oil back up to 360F – and certainly shouldn’t get the oil up to the flash point – in the relatively brief time that you will be frying chicken. But if I were to use my cooker on a non-induction stove, I would definitely do some trials with an accurate thermometer until I knew exactly how much to reduce the heat and exactly what temperature increase I should expect in the pot after capping it. That would be important to me for the sake of safety and also for the sake of process repeatability. (I also have both an electric and a stovetop Chicken Bucket and back when I was using those more regularly I had the process worked out for those.)
Once my 10 minute timer has gone off, I use my long tongs and gently tilt the pressure relief valve, being careful not to remove it entirely. The steam escapes quickly – over about a 20 second period – and when it has almost all vented off I start to unscrew the lid. Sometimes I will gently toggle the pressure relief valve with my finger once or twice during the “unscrewing the lid” process in order to vent any remaining steam through the pressure relief valve.
I remove the pressure fryer lid and, using my tongs, I reach into the fryer and immediately remove the chicken and put it on an wire rack that is sitting on a half sheet pan (like a large cookie sheet with sides) that I then put in a steam oven to rest, like Ken does.
I will note that for a while I used a basket inside my pressure fryer. Although the exact basket that I have is no longer available, it looked like this, but I cut off the plastic/rubber leaving only bare metal:
www.amazon.com/kaviatek-B47D-Stainless-Accessories-Pressure/dp/B079CLQJ5Z/ref=sr_1_3?dchild=1&keywords=8+quart+pressure+cooker+basket&qid=1603488109&sr=8-3
I used this basket so I could pull all the chicken out of the oil immediately when I opened the cooker, and so I could see the chicken better in order to grab it with my tongs.
However, I have stopped using this basket for the time being because it added some awkwardness to the process, and even though the basket I have fits my cooker quite well, it still reduces the capacity of the cooker somewhat, so at the moment it isn’t clear to me that the benefits outweigh the detriments.
So that was quite a lengthy explanation, which was given with the hope that it will help others who come along in the future and keep them from having to put forth as much effort as I did in understanding the basics and learning how to do this (hopefully) safely. I have no doubt that others will have things to add and correct, but maybe this will give us a start.
