Pressure Cooker Pressure Release methods - Normal/Quick, Slow Normal, 10-min Natural, and Natural

Ooops! AD Blocker Detected

This content is FREE because it is supported by advertisements. Please deactivate - or whitelist our site - with your Ad blocker to read it. We appreciate your support and hope you'll find the recipes and info worthwhile the small bother of ads. Ciao! L

Pressure Cooker Pressure Release MethodsThere’s more than one way to open a pressure cooker and each way has its own effect on what’s inside.  What might work for a stovetop pressure cooker, might not work for an electric pressure cooker. We’re sharing the “how’s” for each of these pressure cooker opening methods to get beginners started and the “why’s” for expert cooks to sharpen their skills.

Pressure Cooker Opening Method Quick-reference

Method NameSpeedProcedureElectric
(approx min)
Stovetop
(approx min)
Cold-water QuickFastestMove stove top pressure cooker to sink and pour cold water on the lid. NOT RECOMMENDED--30 sec.
Base ImmersionVery FastMove stove top pressure cooker to sink full of cold water and immerse the base of the cooker in it. NOT RECOMMENDED--1
Normal
(aka Quick Release)
FastOpen the pressure valve on the lid.32
Slow NormalSomewhat SlowOpen the pressure valve a little bit to release pressure slowly, or in short bursts 10 seconds apart.65
10-Minute NaturalSlowCount 10 minutes, and then release remaining pressure by opening the valve. If the pressure dissipates sooner than 10 minutes do not remove lid until time is up.1010
NaturalSlowestDo not do anything. Wait until the pressure has dissipated completely, and the lid-lock has disengaged.20-3010-15

How to Choose an Opening Method

Using the wrong opening method can give you limp veggies, bean mush or rock-hard dry meats – here are a three principles that you must know to choose the right opening method for your pressure cooker recipe:

bullet point The food is still cooking even when it isn’t “cooking”.

When the pressure cooker is both building and releasing pressure, the temperature inside is near or above the boiling point, which means the food is actually cooking during this time, too.  This is generally fine for meats, legumes and desserts.  It is not fine for vegetables that you may want to have more al dente as they continue to cook during this time-  choose the fastest release method  for veggies while more robust foods will benefit from a longer opening method.

bullet point The faster the release, the more movement.

The speed at which pressure is released is directly related to how much movement is inside the pressure cooker – more speed gives the food more movement. When pressure is released, the equilibrium that suppressed the bubbles of the boil during pressure cooking is broken and they begin breaking to the surface again. A fast release will violently release these bubbles, forcefully flinging bits of food and foam onto the underside of the lid and safety valves, while slow opening method,  such as Natural release, delicately allows the bubbles to rise into a  slow lazy simmer.  For foods which you intend to keep whole (like beans) or clear (like stock) use the slowest opening method to get the least amount of movement.

bullet point The hotter the food, the faster the evaporation.

The difference in temperature between the food that comes out of the pressure cooker and the environment can affect the speed of evaporation. The faster opening methods will yield the hottest food with an accelerated evaporation of the food’s cooking liquids and juices. While the slowest opening method will have given the food a chance to cool down and the liquids will evaporate at the speed of conventional boiling.  So for foods which you intend to keep juicy (like roasts) use a slow opening method; while, foods which need reduction after pressure cooking (like a sauce), use a fast opening method.

If this is starting to sound complicated, don’t worry: all of the recipes on this website (and my cookbook) already call for the appropriate opening method. Let’s get into the “how’s”.

Pressure Cooker Opening Methods

This list includes an opening method I came up with (Slow Normal) and another that has been unofficially around for many years (10-minute Natural) –  they add more options to your pressure cookery.  We start the list with the fastest opening method and conclude with the slowest. Further down, there’s an opening method we no longer recommend and one that used to be OK for older cookers but should not be used on modern stainless steel pressure cookers.

NORMAL pressure release

Normal or Quick Pressure ReleaseSometimes this method is called Quick, Manual and, confusingly, Automatic. This is a fast opening method that can take 2 to 3 minutes.  Normal pressure release means that the cook should use the valve, or pressure releasing mechanism particular to their cooker  (such as a button to push, a lever to twist, or a slide to pull), to release pressure.  For thick recipes such as a chili or a risotto the still unopened pressure cooker should be given a few small jolts to release any super-heated seam pockets in the food after pressure is released.  This release method is used for quick-cooking foods and vegetables. It should not be used for most legume, rice and fruit-based recipes. It can be used for meat stew-type recipes (where the meat is completely covered with liquid) – but not ones where tossing the other ingredients around would mush them.

Weighted or jiggle-type pressure cookers may not have this kind of release – we recommend either using Natural Release (see below) or simply using a fork tines to gently lift the weight and release pressure.

SLOW NORMAL pressure release

Slow Normal or Intermittent Pressure ReleaseThis is a relatively fast opening method and can take from 5 to 6 minutes depending on the pressure cooker type (the element in electrics still retains heat after turning off) and fill level (more food will retain more heat).  Similar to Normal release, this method releases pressure using the cooker’s valve,  or the pressure releasing mechanism, but pressure should be released very slowly.  If the valve only allows for pressure to release full-throttle, the cook should release it in very  short bursts- if anything other than steam sprays out of the valve (like foam), the valve should be closed for 10 seconds before the next slow release or short burst. The Slow Normal release is for  occasions where it’s just not practical or convenient to wait for the full Natural or 10-Minute Natural release for tricky foods (grains, legumes and fruits).

10-MINUTE NATURAL pressure release

10-minute Natural Pressure ReleaseThis is a slow and somewhat delicate pressure release, and as the name suggests, takes only 10 minutes – a little more if there is still pressure in the cooker that needs to be released (usually with electrics).  The 10-Minute Natural release allows for pressure to release naturally for 10 minutes and then, if there is any remaining pressure,  it is released using the Slow Normal method.  Conversely, if the pressure in the cooker goes down before the 10 minutes are up, the lid must remain closed and the cooker undisturbed for the full 10 minutes. This method is recommended for grains which continue to cook in the residual steam locked inside the cooker without any additional heat.  The 10-Minute Natural can also be used in place of Natural Release.

NATURAL pressure release

Natural Pressure ReleaseThis is the slowest and most delicate pressure release method, it can take anywhere from  10 to 30 minutes depending on the pressure cooker type (electrics take longer due to their thermos-like construction) and fill level (fuller pressure cookers will take longer).  The Natural release lets pressure release slowly from the cooker once the heat (or cooking program) is turned off .  It’s most recommended  opening for tricky foods that tend to foam or expand  like grains, legumes and fruits to prevent the food or its foam from spraying out of the valve;  foods that need to cool down slowly  such as braised and steamed meats and desserts to prevent their moisture from evaporating too quickly;  and,  stocks to keep the food from tossing the ingredients around in a way that would cloud it.

Two Opening Methods We DO NOT Recommend

Some opening methods can fall out of fashion because they are either too problematic or the materials used to make the cookers (such as 100% aluminum) are no longer popular.

COLD-WATER QUICK pressure release

This method releases pressure by carrying a stove top the pressure cooker to a sink and turning on the tap to drizzle onto the lid without wetting the pressure or safety valves.  We do not recommend this opening method, anymore for the following reasons: the path to the sink may be filled with obstacles (kids, pets) that could trip the cook holding a pressurized cooker;  water could block the valves and cause a reverse-suction (from the quick loss of volume from condensed steam)  that could  bend and damage the metal of the cooker; and lastly, the safety systems cannot properly detect a pocket of pressurized food that may not be released until after the lid is removed causing an eruption of super-heated food onto the cook.  Beware: modern pressure cooker manuals and cookbooks still call for this opening method!  For any recipe that calls for the Cold-Water Quick release, use the Normal pressure release instead.

BASE IMMERSION pressure release

This method releases pressure by carrying a stove top the pressure cooker to a sink  or basin, that is partially filled with water,  and lowering it to partially submerge the base.   We do not recommend this method because:  the cooker could slip out of the cook’s hands and damage both the sink and cooker; and, the thermal shock could warp the metals eventually separating the aluminum base sandwich of modern pressure cookers. Manufacturers stopped calling for this opening method more than 20 years ago – however, vintage cookers or chefs who have been taught from previous generations may still use this opening method. For any recipe that calls for using Base Immersion, use the Normal pressure release instead.

 

Using the right opening method can help a recipe end on the right note but it’s also a question of safety.  The wrong opening method could clog the safety valves or even damage the pressure cooker.

Pressure Cooker Pressure Release methods EXPLAINED

 

 

56 Comments

  1. The cold water release method can cause steam to be ejected from under the lid – yes I know from experience!!!!!! You could mention this steam ejection too. Since the cook could have the cold water running a tiny bit too fast from the tap, the steam ejection is a real problem. The volume of wet steam released could result in nasty scald injuries! There’s also a scary sound of “suction” during the cold water release, maybe it’s a vacuum from the loss of steam?

    I have recipe book, originally published in 1978, that recommends immersing the pressurised cooker in shallow cold water. Very dangerous advice now! Great page.

    1. Thanks for adding to this with your comment, David!

      Based on my own, yours and other experiences I have heard from readers, I’m probably the only person who warns against the Cold-Water Quick opening method. I think I’ve completely removed it from the older recipes on the website and I don’t call for it in any of the recipes in my cookbook, either – but I’ve been wanting to outright warn everyone against using it, altogether, so this article gives me a chance to do so officially.

      Ciao,

      L : )

      1. Your pasta casserole and spicy pasta (Tonight’s dinner) still mention quick in the executive summary. The detailed instruction has been changed though.

        1. Thanks for catching those, Greg – I have updated them!

          Ciao,

          L

      2. love your advice and recipes…everything has turned out well. in regards to cold water to release pressure you are so right whats a few minutes to wait as the pot is so quick anyway

  2. My old Fagor multirapid manual only mentions two ways to release pressure, the natural way and the quick way under running water. I discovered you can push the pressure selector on the handle forward to release pressure too.

  3. Thanks for these tips, Laura! I usually use the cold water quick method if I’m in a hurry, but I guess I’ll need to reconsider…!

    1. Franco,

      I only use it for “emergencies” – those are few and far between so almost not at all!

      Ciao,

      L

  4. Hi Laura – just found this site and LOVE it. Thanks so much for all the good advice about different releases. I have a Fissler and I use the valve for quick release and wondered how the effect differed from cold water release. I also really appreciate understanding how and why different release methods are used.
    By the way, You still reference the cold water release method in you article about 5 ways to cook eggs.

    1. The two methods are fundamentally different in the way they work
      The cold water method reduces temperature. This will slow or stop cooking almost immediately and cause the gas (steam!) in the PC to condense creating a partial vacuum inside. This will pull the valve down and allow the outside air in to balance pressure. However if the valve is blocked, either by the water stream or something in the cooker blocking it, very bad things can happen. If you ever need to crush a 44 gallon drum, pour some water in. Heat it until steam is coming out the hole in the top. Screw the cap on tight, remove the heat source and pour cold water on it. Believe me it is positively scary. You DO NOT want to do this with your pressure cooker. David above mentioned the possibility of steam escaping around the rim. This is probably due to the gasket shrinking as it cools, thereby reducing the effectiveness of the seal. Remember the gasket is closer to the water steam, so it will cool faster than the contents.

      Valve release on the other hand, reduces pressure without reducing temperature. This will cause the contents to boil vigorously which will subsequently lower the temperature of the liquid inside. But not the vapour. The hottest part escapes the liquid as steam, so the steam is hotter than the liquid. Incidentally this is why water boiling in an open pot will stabliise at 100°C the hotter molecules escape the pot. The vigorous boiling can cause foaming which can block the valve or even cause the contents to spurt out. Having a larger air gap reduces the risk of this happening which is why foods which foam should not go over the half way mark. This method can damage delicate foods like custards as the boiling can occur inside the food destroying the structure. Even things like potatoes can be broken apart. Great if you are aiming for mash. Less so if you are trying to emulate a roast potato. .

      1. Quite right about the sudden collapse of steam (as in your 44-gallon drum example). Depending on the method of doing the calculation, water increases in volume by a factor of 1600 or 1700 when it turns to steam. Likewise, it collapses by that factor when it condenses. Big difference, lots of power!!

    2. Welcome Lalyc and thanks! I have updated that article to remove the photo of the cold-water quick release.

      Ciao,

      L

  5. Can’t see any advantage in waiting 10 minutes or so for the cooker to cool naturally? Surely this time negates the advantages of pressure cooking in the first place. I drivel cold water over the lid avoiding the valves and this works fine – as per instruction book.

    1. Fairwinds, the advantages of using Natural Release are described in the article above, so I’m not going re-state them here. Since you pointed out a valid concern about negating time savings, take a look at my side-by-side comparison of conventional vs pressure cooking times in this chart:
      https://www.hippressurecooking.com/infographic-speed-up-slow-cooking-with-pressure/

      The chart includes the time the cooker needs to reach pressure and open with natural release. As you’ll see the time savings are significant – even when waiting for the superior results that are achieved by using Natural Release.

      Ciao,

      L

      1. Pressure cooker times for beef roast are drastically different on this site. https://www.hippressurecooking.com/pressure-cooking-times/ says 75 minutes, but following the link in that chart here (https://www.hippressurecooking.com/pistachio-crusted-roast-with-carrots-and-potatoes-lesson-7-one-pot-meal-pressure-cooker-pot-roast/) says 30-35 minutes, and the link you presented above (https://www.hippressurecooking.com/infographic-speed-up-slow-cooking-with-pressure/) says 45 minutes. Which is it?

        1. Thanks for your message, Dawn and also for including your lovely selfie. : )

          The Beef Roast recipe, is a tested recipe and has more accurate time (30-35 minutes). The infographic says 45 minutes but actually includes the 10 minutes it takes for the cooker to reach pressure (see asterisk in infographic).

          The cooking time chart is based on the average temperatures given by various manufacturers- though they are notoriously long so I’m going to update it with my personal testing results. You should always refer to your manual recommendations first – and if the differ from mine go with the lesser time first, then check the center temperature and pressure cook more – if needed. You can always pressure cook more, but not less.

          BTW, bringing a pressure cooker recipe back up to pressure takes much less time than the initial climb to pressure because the cooker and food are already hot – it’s usually 2 or 3 minutes.

          Thanks for writing!

          Ciao,

          L

    2. Fairwinds, you are assuming that the only reason to use a pressure cooker is the time savings. While that savings can be significant, depending on what you’re cooking, many of us prefer the flavor enhancement as well the nutritional benefits that are achieved with pressure cooking. I follow Laura’s advice; she hasn’t steered me wrong yet. She really knows her stuff!

    3. Hi fair winds and welcome,
      In addition to the points above, there is an economic saving as you are using much less fuel to heat your pot

    4. I agree. Why not just cook in a regular pot if you’re gonna use the normal methods. I just cold water everytime whether I’m in a rush or not.

      1. Welcome Danny,
        There are risks involved in using cold water release. If you are prepared to take them, then you have to accept the potential consequences.

        Also the timing of recipes includes the cooking during the cool down phase. If you negate this cooking time, you run the risk of undercooking your food. You therefore increase the risk of food poisoning. Again, if you are prepared to accept the risk that is up to you.

        As for why not just cook “normally”…
        1. There is usually still time savings.
        2. There is always energy and cost saving. If you run your stove for five minutes to cook under pressure and then wait 25 minutes for pressure to drop, but have it on for 30 minutes cooking normally, then you are saving 25 minutes worth of energy and its associated cost. My energy costs have decreased noticeably since I started using pressure cookers.
        3. I often cook multiple things in one pot in my pressure cooker. Cooking “normally”, this rarely happens. That means more washing up. And even more energy use.
        4. Flavours often infuse better in the PC. I end up with a better tasting dish.

        I by no means cook everything under pressure. Not every dish I cook lends itself to this technique. But they are a wonderful addition to to my kitchen.

  6. “the still unopened pressure cooker should be given a few small jolts to release any super-heated seam pockets in the food.”

    Do you mean…like bang the pot on the counter??? What is “a few small jolts?”

    I love love love your site. Thanks for all your help. I just got an Instant Pot and this site is getting me through the learning curve.

  7. Hello and thank you for the great information. Regarding release methods, I’ve been reading up and practicing but am still confused. I understand that meat should be opened with natural release, so as not to dry out it out, and that vegetables should done with quick release so as not to overcook. I also read your suggestion of “phasing in” ingredients that have different cooking times – so that if I was cooking a braised type dish of meat with vegetables I would do the meat for an appropriate amount of time and then add the vegetables in later.

    However, I don’t understand which release method I would use for each phase. Natural release for the meat, then add vegetables, bring back up to pressure, then after cooking time quick release? Will a quick release at that point that not dry out the meat?

    1. Belonagaster, if you’re just popping off the lid and tossing in the veggies you can do a quick release. The important thing, to keep the meat moist, is that you don’t stand there looking at it with the lid off or put it on a serving platter. It literally takes less than a minute to evaporate ALL of the juices from a roast. Been there. Cooked that. Ruined it. : )

      Ciao,

      L

      1. laura
        evaporation may have a roll in drying meat but i think it is mostly due to the pressure change or rather the rate of change.
        one description of meat may be, closely packed fibres with moisture between.
        when you release the pressure rapidly the meat has to de-pressurise as well, it will also be at 15lb? from the centre out, the rapid change of pressure means that pressure will rush out of the meat taking the moisture with it, leaving closely packed fibres without the moisture between.
        this pressure change is exploited to vacuum impregnate timber with preservative, an inversion of the above.

        many years ago i worked at a timber yard where they had a machine they called a vac vac.
        it looked a bit like a submarine, a stack of timber on a trolly was wheeled into the chamber at one end which was then sealed and a vacuum was generated in the chamber, preservative was then added to the chamber, on releasing the vacuum the preservative was sucked into the timber as the pressure equalised.

        the first link below describes the process better than my memory, the second has some pictures of the plants, the one where i worked was a single chamber.
        also anything that has or forms a skin is likely to explode due to the rapid pressure change.

        http://www.wenbans.com/services/treatment/

        http://www.isve.com/en/vacuum-impregnation-plants-imp-vac

        1. Ian, If you’re doing things right -pressure will not quickly leave the meat. ; )

          I try not to reference everything I say, but as you become more familiar with this website, you’ll find that a lot of the information I share is well researched (mostly triggered by personal experience and wanting to find out more). That’s also why some of the things written here might also contrary to what other people often share, or believe, in Facebook groups and whatnot. For example: “sugar in a recipe scorches the pressure cooker” (uhm… no) – see my article on pressure cooking tomato-based sauces for the details.

          Here is a good explanation the physics behind my statement “The hotter the food, the faster the evaporation”
          https://van.physics.illinois.edu/qa/listing.php?id=1440

          I too, love to learn about new things and appreciate any feedback and corrections from readers, as well. Thanks for sharing the lumber treatment and preservation process – it’s fascinating!

          Ciao,

          L

          1. thanks for that link, a lot for a non scientist to digest, but clearly evaporation plays a greater part than i thought, put the two together and create a disaster :-)

            i know it’s popular but i don’t have any social media accounts and no wish to get one, although i think i’m signed up to google + due to getting an android phone but never used it, technology wastes enough time as it is :-)

            ian

  8. I have a question about the natural release methods. If the cook is using a conventional electric rangetop, is the PC removed from the fob so no further heat is added, or does one simply turn off the fob and leave the PC on it?

    1. You need to move the cooker to an un-heated element, or trivet, to begin Natural Pressure Release.

      Ciao,

      L

      1. Hi Laura! Do make sure that is clear up in the main article, under both the main natural release methods, as well. Thanks for the answer!

  9. The terminology that has developed over the decades has certainly resulted in a lot of confusion. I commend you for using the term “opening method” — it’s actually the only clear and accurate term! “Normal” is informative and correct only if you “normally” cook only foods that require that opening method. (Most of my cooking requires the misnamed “natural release”, so THAT is what’s “normal” in my kitchen!) “Manual” is a much more accurate description of that method, and “slow manual” would be a better name for your “slow normal” method. But the worst offender is “natural release” — because in that opening method, there IS no release! Nothing exits the cooker. Rather, the pressure SUBSIDES as the pressurized steam turns back to water entirely within the cooker. “Natural cool-down” would be a more accurate and informative term.

    (I am under no illusion that my comments will result in new industry standards, but I had to put my two cents in ;-)

    When I need a slow manual release and the food is prone to splatter or foam, I sometimes lay a damp dishcloth or paper towel across the lid. (“Assisted slow manual”??) The damp cloth creates a cool but not cold patch on the inside of the lid where steam condenses more quickly. The cloth begins steaming within 15 seconds or so, demonstrating that it is transferring heat out of the pot, but not nearly as violently as the old cold-water methods. I wonder if you’ve tried this, Laura, and what your opinion would be.

  10. Dear Laura,
    I had a nasty experience with making stock in my WMF Perfect yesterday which resulted in burns to my right hand and lower arm, and I still don’t understand the physics behind what happened. Maybe you can explain? I made a bone broth on Sunday night using just a beef leg bone, some bacon bones and some salt in a perforated basket and filled the pressure cooker to 2/3 full. On Monday morning I removed the perforated basket of bones and left the stock with a thick layer of liquid fat on top on the stove for the day (not enough room in the fridge). Come Monday evening I thought: time to separate the stock from the fat and put the stock into containers for freezing, but first I’ll heat it up again. I sealed it up and brought it up to pressure and cooked it for a few minutes and then took it off the heat. I released some of the steam faster than a natural cool down period. It didn’t take long and the pressure gauge showed their was no pressure left and I could take off the lid. There was about 1 cm of clear fat on top, opaque stock underneath and the pressure cooker was about half full. It was hot, but not moving and I left it several minutes. It was sitting on a cold element. I didn’t want to pick up something so hot and heavy to pour the hot stock and fat into my 500ml fat separating jug, so instead I dipped my metal measuring cup through the fat and into the stock. At the point when I penetrated through the fat and into the stock the whole thing boiled and erupted out of the pot. I got hot fat and stock splattered over the hand that was holding the cup, my neck, my clothes, the stove and the floor. That was the end of dealing with the stock that night. I spent 2 hours cooling my burns first under cold water and with frozen free flow items from the freezer, and then went to the after hours medical centre to get them dressed. Now it’s 24 hrs later and I can report that the burns look not too severe. No raw wounds, some blisters and some red patches. However I am mystified as to why the stock erupted when I put the cup into it. Was it possible for pockets of trapped gas to exist in a watery liquid with just a bit of sediment from the meat in it? The holes in the basket are only about 5mm so sediment from meat was fine. How can I predict when a hot liquid will behave like this in the future?

  11. It sounds as though the liquid was superheated. No gas trapped under the fat layer, but the liquid was prevented from boiling by the fat layer even though it was above 100ºC (212ºF). When you pierced the fat layer, you allowed the liquid to boil vigorously resulting in the eruption you experienced all too closely.

    It is also possible that there were no nucleation sites in the liquid, so boiling point was raised. Adding the cup provided a nucleation site and the boiling resulted. I have seen this when microwaving water, but never in a PC. I also think the cloudiness of the stock would have provided plenty of nucleation sites so I think this explanation is less likely to be the reason.

    If you are unfamiliar with nucleation sites, it is what causes the bubbles in a glass of champagne to stream from specific points in the glass. The bubbles form around tiny imperfections. Mythbusters once exploited the idea by dropping a mint into a bottle of soda. The mint provided LOTS of nucleation sites and the resulting eruption was spectacular to say the least. Nucleation is also why cloud seeding can result in rain.

    I am not sure why you reheated at all. Your plan was to separate the fat. Surely it would have been easier to scrape the cold solidified fat off the top of the stock with a spatula or fish slice. Beef/bacon fat should have been fairly solid at room temperature unless it was a very warm day. Oil would be a different matter, though I have used a basting pipette to remove oil in the past. Then with most of the fat removed, it would have been a simple job to scoop the stock out.

    If you really did need to reheat it, doing so with the lid off would have helped. Or if your aim was to kill any bacteria that may have grown, then removing the fat BEFORE reheating under pressure would have been best.

  12. Hi Greg
    Good to get your thoughts. Yes my first theory was that the stock was super-heated and unable to boil under a 1 cm layer of fat, but others with a technical mind discounted that idea. I still think that it is the most likely explanation though so thanks for your vote on that one.
    I agree with you that cloudy stock means there were lots of nucleation sites available so lack of these does not adequately explain the phenomenon.
    Given my experience I now know that boiling without pressure would have been a preferable choice, and that is what I did on Tuesday evening.
    Why I reheated it? The fat did not solidify adequately at about 15 degrees Celsius for me to scoop it off. It was semi solid. I have a best method for removing liquid fat (using a fat separator – a jug with a spout that pours off liquid from the bottom) and a best method for removing solid fat (a fork or slotted spoon) but half way in between renders both these methods less effective. It was easier for me to heat it up than cool it down (lack of space in fridge).
    I’m pleased to report that my (remaining) stock is now in the freezer in cups to create large ice cubes of stock for future use. I find this a very convenient way to store home made stock. And the fat I removed is in the garden feeding the birds (it is winter here in the southern hemisphere).

    1. Alicia, Greg is a former science teacher – so I would say that his “vote” carries a bit more weight than one from someone “technically minded”. When I read what happened I suspected trapped heat – the same mechanism of what happens in the microwave with “explosive” water – but I would not have been able to explain the “how” the mechanism works as Greg has!

      Ciao,

      L

    2. Alicia, I know my comment is coming 11 months late but in case you get notified and for anyone else reading this I wanted to point out that leaving stock sit at room temperature for a day or even several hours is dangerous. Even if you do it “All the time” and everything was OK. In reading many cookbooks over the years I learned that homemade stocks made from meat are so filled with nutrients that bacteria attack and grow in this food faster than any other. It is highly recommended that you chill stock to below 40F as soon as possible (even if you have to remove other items from your fridge or put ice in a cooler chest). Even then it will only keep for a couple of days before going sour. The minute mine is cool enough to handle, I package and freeze it. I stir the fat through it and separate it out when I take it out of the freezer to use. Sometimes (especially with chicken stock) I want a small portion of the fat for the recipe.

      1. Thanks RK, and Welcome!

        Ciao,

        L

  13. That’s strange. It’s winter in my hemisphere too. :P but your winter is a bit warmer than mine. Currently 8° here at midday. I have a fat separator but don’t use it much as it only holds 250ml. Not much use when making a several litres of stock. What I do use for semi solid fat is a skimmer I picked up somewhen. It is basically a very flat fine sieve. As long the bowl is big enough to slide it in, it works really well. But my baster works really well too both for sloppy and liquid fat layers. In essence it is a giant eye dropper. I think it was called a turkey baster in the shop but I have never in my life cooked a turkey.

  14. I agree with Greg’s diagnosis. Several years ago, I led a rehabilitation project on the steam-heating system in my 90-year-old building, first spending many months educating myself about such systems. One of the first things I learned (and observed, in the sight glass of the boiler) was that even a thin slick of oil on the surface of the water in the boiler reduces the ability of the liquid to turn to gas. Small steam bubbles that form first would normally escape the surface easily, but oil prevents that from happening. The small bubbles must consolidate into larger bubbles in order to have enough buoyancy to penetrate the oil. (The sight glass revealed a wildly fluctuating liquid level as the uneven boiling caused the water to slosh from one end of the boiler to the other.) If the bubbles cannot leave the liquid, then their heat energy remains below the surface, and the temperature rises. A full centimetre of fat on top of your liquid stock would wreak havoc with the liquid-to-gas conversion, leading to a superheated liquid.

    (Also interesting to note that the WMF web site features a prominent photo of the cold-water release method — time to get on their case, Laura!)

  15. Hello,
    I was reading your web page on pressure cooking and have a question. I have an electric pressure cooker, and I made some beef with various vegetables, and after the pressure went down and I was able to remove the lid, I stirred the contents and it erupted violently throwing liquid and veggies well over 12 inches into the air (and all over the cabinets as well).
    My question is; what caused this eruption? I’ve made this dish many times before without issue.
    Thanks,
    Bob R

    1. Bob, this can happen if the liquid was thickened with flour or starch, flavor packets or condensed soups. Basically, after the pressure was released the thickened liquid maintained a pressure steam-filled pocket and stirring freed the pocket. I don’t recommend pressure cooking with the aformentioned ingredients – they can always be simmered in at the end without any detriments in flavor. A well-written pressure cooker recipe that has an eye on safety will automatically include these steps, or preculde those ingredients.

      The previous times you made this dish and this didn’t happen is just luck.

      Ciao,

      L

  16. Thanks for this article! I’m just getting started and this is a big help. If the industry ever wants to clear things up, terms could be clearer for newbies like me… maybe “quick valve release”… “slow valve release”… combination release and natural (lid) release…? Would be nice… : ) What do you think?

    1. I agree, for a long time I would mix up normal and natural release. Maybe “remove from heat and let her rip” and “remove from heat and take a catnap” would be more understandable or a simple image of a hand releasing the steam.

    2. Totally agree. So glad I finally found this page, as I looked directly for the recipes first and was confused. What makes it worse is that other sites seem to have settled on Quick Release (QR) or Natural release (NR) so therein lies some of the confusion.

  17. hello laura

    ignore the nay sayers, your descriptions are just fine!
    i too did not know what you meant by normal, natural so i clicked on normal and that is how i’m on this page, it’s one of the things that makes this site the best i’ve seen and i’ve seen quite a few.

    by detailing what you mean by the terms you use, and giving additional information relating to the use of water to release pressure and the potential effects of doing that, it makes this site better than any other i’ve seen, your charts are the most comprehensive i’ve seen, few include anything about elevation effecting operation, i shall no doubt return as it’s very clear that you know your subject, unlike so many others on the net.
    bookmarked!

    1. Thanks, Ian. I think the enthusiasm brought on by pressure cooking motivated lots of people to jump into sharing their trials and errors. Perhaps, before they became familiar with this cooking method themselves. Unfortunately, this has created a huge glut of low-quality recipes, websites and e-books. The problem being: recipes are just asking for a scorch or just down-right dangerous. If you follow the few websites that collaborate directly with manufacturers or, as in my case, have worked as consultants for them you’ll immediately notice the difference in quality and consistency.

      Personally, I’m fascinated with the science behind things so I really enjoy sharing what I find in a way that is easy to understand in the hopes of sparking ideas and new recipes from my readers.

      Welcome, and thank you for sharing your appreciation!

      Ciao,

      L

  18. my pressure cooker lid got stock due wrong and tilted to one side. please what can I do to open it?

    1. Hi,
      Can you explain the exact problem more clearly. I think you are saying you cannot get the lid off. But I am not sure.

      Please explain exactly what the problem is and how it happened. Include the make and model in your explanation.

    2. Tap the handle lightly with a hammer to “unscrew” the lid, then tap it lightly in the other direction. Then try to open it again. Continue, until it yields!

      Ciao,

      L

  19. Natural cooling is great in that it keeps using your heat to cook food way after the stove is turned off. I have been experimenting with placing the cooker into a box that has a circular hole packed with old towels and rags with a spot that the handle pokes through. I know that some will see safety problems with moving a pressurised PC but it can be very close to the stove. The extra cooking time this gives is amazing and you can get up to 40 minutes before the cooker has lost all pressure. This enables you to cook the food for even less time because it cooks longer in the hot box. Great if you want to have the meal two hours after cooking as it is still hot enough to eat -just leave it in there and open before you eat. I’m a major burns victim (not through anything I did or pressure cookers) so I would not do anything stupid. I would not move a PC very far if it is pressurized and more than half full. Afterall my mum and I used the cold water method for vegetables at least 2 nights a week and that was a three metre hike from the stove to the sink. Do what you are comfy with. I want to make a hotbox for my cooker that is polyurethane with an aluminium foil coating. I will let you know how it goes.

    I understand if you don’t approve this post but I love getting more for less. It saves fuel and the food is tasty.

    1. Dale, it might be a little easier to just wrap a thick blanket around the pressure cooker, and then slide the box on top of that. Heat rises so there is no need to lower the cooker into the box. I would re-think using Polyurethane. I did a little google search to find out the melting point and this is what I found out…

      “Polyurethane does not have a melting point because it is a thermosetting polymer, so when it is made, it becomes irreversibly hard. When exposed to extreme heat, polyurethane ignites and burns”

      So, no, I don’t approve of the materials for your new hotbox design.

      Ciao,

      L

      1. You might want to consider a wool fire blanket – since they are both fire retardant AND insulating. In other words, you won’t have to worry about it igniting.
        http://amzn.to/2vM50jT

        Ciao,

        L

      2. Interestingly, Kuhn Rikon has a model that does just this. I think it is called Duratherm. They have a range of non pressurised insulated pots. But I am pretty sure there is one pressure vessel done the same way.

        @Laura, i came across this:
        Polyurethanes Melting Point: 85°-121° Ignition Temperature: 416°
        I assume ºC as other temperatures on the same page are.

        Source: http://www.tcforensic.com.au/docs/article10.html

        But yes. I agree a fire blanket would be better.

        1. I checked further and found this on the Wiki:
          “While most polyurethanes are thermosetting polymers that do not melt when heated, thermoplastic polyurethanes are also available.”

    2. if i remember correctly it’s known as haybox cooking, and came about to conserve fuel etc.
      you could google it, you may find out others have tried it.
      this may get you started.

      https://en.wikipedia.org/wiki/Haybox

  20. Thanks guys for the feedback – I have another insulator here called Rock wool that I grow seedlings in -it melts at 1000c so should be OK. I just need to have a cooler spot for the PC handles – I will use an old pc

  21. I’ll be checking more of your cooking site after my comment so please excuse this if it’s already been addressed before as this is the first time I’ve come across your site.

    I rarely use recipes except for something I’ve never tried before and then, mostly as a guide. Usually I only use quick release (normal pressure release) for steamed vegetables or dim sum foods which would be ruined by further cooking. With most other foods, I take into account the additional time at heating up and cooling down and shorten the time I cook at either low or high pressure. (I have an Instant Pot.) That way, I can use natural release and nother worry about splatterm during pressure release. I especially like it for thicker sauces, congee and rice pudding.

    I’m guessing many recipes are similar for foods that would otherwise gunk up valves but I do it for everything (except for those I mentioned). Does anyone else do similar?

Leave a Reply

Your email address will not be published. Required fields are marked *

 notify me of new comments

upload a photo with your comment (max size 500k)

Comments containing links, photos or from new members are moderated may take a few hours to display.

Please note that by commenting you will be automatically subscribed to the newsletter.