Since I wrote about my new favorite kitchen appliance, the Instant Pot pressure cooker, I’ve gotten a lot of comments and questions about if pressure cooking is a healthy way to cook food or if it destroys nutrients.
It is certainly a logical and valid question… in fact it was the question that kept me from trying a pressure cooker for years until I finally decided to research it, and what I found was fascinating.
Growing up, I considered a pressure cooker an antiquated kitchen tool that elderly relatives used and that was most useful for canning. Some pressure cookers can double as a canner, which is probably why my elderly relatives used their pressure cooker more than those in my generation, but it turns out I had missed out on a lot of important points in my quick judgement!
How Does a Pressure Cooker Work?
A pressure cooker is a pressurized (of course) pot that cooks food using a combination of heat and steam. While it would seem that high heat is required, the steam and pressure actually provide much of the cooking power. A pressure cooker has a valve that seals in the steam, creating a high-pressure environment. This is beneficial because it increases the boiling point of the water or liquid in the pot and forces moisture into the food in the form of steam. Both of these help the food cook much more quickly.
How does this work?
Consider this- water boils at a lower temperature at higher altitudes. This is because the lack of pressure allows the water to boil at a lower temperature. You may have noticed special high-altitude cooking instructions on certain recipes and this is partially why. The lower the temperature at which water boils, the faster foods start to dry out and the more difficult it can be to cook. This is also why it takes longer to cook food at higher altitude.
Pressure cooking essentially does the opposite of altitude, it increases the boiling point of water and decreases the cooking time. Since steam can’t escape from the pressure cooker, you avoid water-loss and are able to cook foods without losing heat.
One big advantage of a pressure cooker is that it can cook foods much more quickly and energy efficiently than other methods like stove top, the oven, or even a slow-cooker.
Does Pressure Cooking Use Really High Heat?
This is where some of the confusion starts to come in. Many people assume that since pressure cooking cuts down the cook time so dramatically, it must use a much higher heat. This isn’t the case at all.
As described above, the shortened cooking time is a product of the increased pressure, not increased temperature at all. When researching, the highest recorded boiling point of water in a pressure cooker I could find was 250 degrees. That is still lower than the temperature that most foods are prepared at in the oven or stove top and about the same as a slow-cooker.
In other words, a pressure cooker may cook foods at a lower temperature than most other cooking methods, utilizing the pressure to improve cooking time and efficiency.
Does a Pressure Cooker Destroy Nutrients?
I completely understand this question, as I had the same one. At first glance, the idea of cooking foods more quickly seems too good to be true and it just seems logical that there is a downside, such as a loss of nutrients.
Fortunately, in researching this question, I found that the reverse is actually true!
Readers have asked if a pressure cooker uses high heat (see above) and if this creates the similar negative effects of high-heat methods like grilling and broiling. Again, it makes sense until we delve into the science of heat and pressure and understand that the increased pressure is what creates the faster cooking environment, not higher heat.
To reiterate, pressure cookers actually cook at a lower temperature than most other methods (steaming, roasting, etc.) but do it more efficiently. All cooking methods reduce nutrients to some degree, but I was surprised how much of a difference the cooking method could make!
In fact, a 1995 study found that pressure cooking preserved nutrients in food more than other cooking methods. Another study measured levels of Vitamin C and B-Vitamins in food and found these levels of vitamin retention (the amount remaining in food after cooking):
- Boiling reduced nutrients the most with a range of 40-75% retained (up to a 60% loss of nutrients!)
- Roasting and steaming preserved up to 90% of nutrients (but in some measurements, almost half of nutrients were lost!)
- Pressure cooking did the best job at preserving nutrients with a 90-95% retention rate
This makes sense when you think about it. Since pressure cooking doesn’t require a much higher temperature and shortens the cooking time, there is less time for nutrient loss. For this reason, pressure cooking may actually preserve nutrients better than other methods of cooking.
There are a couple of notable exceptions to this rule:
Pressure cooking does seem to deactivate certain properties in food like phytic acid. I explained in this post about traditional preparation methods for grains how reducing phytic acid and lectins makes the nutrients in foods like grains and beans more absorbable and less likely to irritate the digestive system. Pressure cooking seems to do a better job of deactivating these substances than other cooking methods.
An Important Caveat
There have been conflicting studies that showed that higher levels of nutrients were lost with pressure cooking, but follow up research revealed that most of the nutrients were actually just transferred to the cooking liquid.
For this reason, I make a conscious effort to use only as much cooking liquid as is needed when using a pressure cooker and to re-use the liquid in the meal by making a gravy, drinkable broth or sauce of some kind.
What Can You Cook?
I’ve personally only experimented with roasts, broth, meats, soups, stews, vegetables and rice in the pressure cooker (this is the one I use), but there are instructions and recipes for cooking virtually everything in a pressure cooker (including cheesecake and hard-boiled eggs!).
Many people love the ability to cook rice or beans in under an hour in a pressure cooker but I love that I can prepare a roast in under an hour!
Pressure Cooking: Bottom Line
Like any method of cooking, pressure cooking does destroy some of the nutrients in food, but it actually preserves more than any other cooking method.
With newer electric pressure cookers (like the Instant Pot), pressure cooking is a convenient and healthy way to get food on the table for your family more quickly and easily while still preserving the nutrients in your food.
Do you use a pressure cooker? What is your favorite way to use it?
Discussion (141 Comments)
My Mother used a pressure cooker for pot roasts on Sundays but I don’t remember what else she used it for. Unfortunately, it was one of those aluminum ones. They also used other aluminum cookware, some Teflon….both had dementia in their latter years. The pressure and hissing of the escaping steam was always a little intimidating to me. It sounds as though a good cooker would be a wise investment.
My Grandmother used a pressure cooker and had one of those events where the ceiling became decorated, LOL. I was not a witness to it, though.
Great information, WM!
Yes, my mum also had a decorated ceiling once, with a stove top pressure cooker making oxtail stew! God it was a mess! But we saw the funny side of it. And it never stopped her using it again!
Pressure cookers destroy enzymes so don’t use it them use raw food as much as possible.
The ‘decorated ceiling’ comments made me chuckle. When we began noticing our Dad forgetting, we began spending the weekends with him to assess. One day he put beans in the pressure cooker. After a short while, we heard a weird noise. A geyser of bean juice was hitting the ceiling. He tried to put the nozzle on correctly with his bare hand. Fortunately he yanked away quickly. This was a big lesson for us. Please ‘borrow’ the pressure cooker when your parents are no longer functioning at 100%. Had I not been there, it could have ended in a bad situation. Also, check the rubber ring to make sure it’s in good condition.
Here in Brazil we use it a lot. It is one of the main pots in every kitchen, since we cook beans all the time.
15 minutes after reaching pressure and they are done!
My husband loves cooking chicken breasts on it. Simply cook them with some water, then drain the water out, add seasoning, seals it back and shakes the pot. The chicken practically melts with the shaking. Voilà!
Hi Mariana, another brazilian here living in Germany but not without my “panela de pressão”! Great tipp about the chicken… how long do you cook it before “shaking it up”? Obrigada!
Thank you! Last wk. a few people helped me settle this in my mind but you have cemented it. I appreciate you & the work you do to help all of us.
I too love my pressure cooker. I have a Fagor Duo 6qt cooker that I use on a gas stove. It defiantly cuts cooking time big time. I found cooking beef short ribs 40 minutes came out so much more tender than cooking all day in a slow cooker. You can cook almost anything and flavors are so much more concentrated.
You inspired me to dust off my electric pressure cooker. I made a pork roast but it didn’t have as much flavor and wasn’t as tender as when I make it in the crock pot. Should I have cooked it longer? I’m kinda lost when it comes to cooking with it. Any suggestions would be appreciated.
I’m glad you’re extolling the virtues of your InstantPot. I’ve had mine for 4+ years and would be lost without it. Don’t forget to mention how great it is for hard or soft boiling eggs and also for making perfect rice every time. Also, don’t forget to talk about how pressure cooking destroys the anti nutrient lectins in beans which are NOT destroyed by traditional stove top cooking. So for the best digestion with beans (as well as the fastest cooking times), use a pressure cooker.
A point of correction. Breakdown of food constituents is done by time at temperature rather than pressure. Chemical reactions proceed faster at higher temperature. Cooking is chemistry.
Boiling point is directly limited by pressure in a linear relationship. Water will not get hotter than the boiling point (ignoring superheating). Sea level is a convenient reference point for boiling pure water. It is defined as 100C at 760 mm by mercury barometer. (212 F at 14.7 psi) At 15,000 ft water boils at 183 F, at 5000 ft (Denver) at 202 F, sea level 212 F. In my pressure canner my weight set produces 5 lbs over sea level or 220 F at 19.7 psi, 10 lb over 235 F, 15 lbs over 250 F. Pressure limits all cooking in water, all the time. Providing a closed atmosphere where boiling point (temperature) can be forced far above ambient is an efficient way to reduce cooking time in water, and saves energy.
We usually prevent food reaching the equilibrium temperature of a hot oven. The air temperature may be very much greater than 250 F but cooking temperature is again limited by the boiling point of water in the food. Food cannot get much above this until the water in the dish has evaporated. Then, the temperature can zoom up and quickly burn the food. Searing by direct contact with hot metal or fire is controlled to the very outside layer of the food and is possible because the water at the surface flashes off, hence the sizzle.
Flavor infusion comes from opening the structure while immersing the food in flavored liquid, the same occurs at lower temperature but requires more time.
So what are you saying about the nutrients?
So how does that impact the nutrients?
Hi! I used an old-fashioned Presto 6qt for the last 10 years, or so & absolutely love it! We cook mostly chicken and bone broth in it with different Thai curry recipes & our new favorite is gf BBQ chicken quarters. The flavor goes all through the meat, every time. Sweet potatoes are a great addition to most meats.Thank you Katie for posting this, as I have always wondered about the nutrients even though the flavors are always yum!
Please post some recipes for pressure cooker bbq and thai curry. Sounds delicious.
I dont understand how you would get any stock from this method, I have used a pressure cooker for veg etc when I was first married 34 years ago.
When I’be done this you use so little water that there is barely any liquid, do you ignore the less water and fill it to the top.
Thank you! I have always wondered this!
I love my pressure cooker. I makes the best bone broth! That is what I mostly use it for. I also have an excellent beef soup recipe that we love, and a cauliflower curry I love. I would love to get a trivet for mine and try doing roasts or chicken!
I haven’t had luck doing beans, I find the outsides don’t soften up enough.
You still need to pre-soak them overnight or use the quick-soak method (bring to a boil for 2 min and then let sit, covered for an hour.) I make legendary bean soups… Add the salt AFTER cooking.
Pressure cooking beans for an additional 30-40 minutes really softens beans.
Over night soaking is necessary for cooking beans of any type in Pressure Cooker. Adding a small pinch of sodium bicarbonate (cooking soda) softens and well cooks beans much faster. Only a very small pinch is required.
I just made navy bean and ham soup in pressure cooker it took 42 minutes no pee soak and it was perfect beans were soft.
I definitely do NOT suggest a pee soak! 🙂
I was glad to learn that pressure cooking in general doesn’t reduce the nutritional content of foods, as much as certain other cooking methods do. Currently, my only pressure cooker is a microwave pressure cooker. Can I expect to get the same good nutrition from foods cooked in my microwave pressure cooker, as we can get from foods cooked in a conventional pressure cooker?
You have to disk the beans overnight in most cases.
Fill cooker with beans, add boiling water and close the lid.
Next morning, or 8hr later, cook them like you would normally.
(Vegetraian family from India, thats how it is cooked there.
Hi Katie! I love what you’ve written here. But I did have a question, not about nutrients, but about digestability. I’ve been battling Lyme disease for over 10 years now. One of the side effects is that when I get really worn down, my digestion also weakens. I’ve noticed that pressure canned meats are particularly difficult for my stomach to process. Could it be possible that pressure canning/cooking destroys something my gut needs? I haven’t noticed this issue with slow cooked or oven-cooked meats and it has me wondering???
That’s interesting… I usually find that pressure cooked meats are easier to digest, but every body and gut can be so different. Have you tried using HCL to help stomach acid? I can’t think of what might cause this reaction but I think it is always important to listen to your body!
I adore my pressure cooker, I do remember my elders (Grand Mother, Grand Aunts, Aunts and Mother) using it all the time on the Aga stove ( I would love an Aga but living in a concrete jungle like New York it is not possible. I do soups all the time even the beef bone broth and the chicken bone broth in stead of 24 – 48 hrs of cooking I do it on low heat for 6 hours.
I make a herbacious green soup with chicken bones for a recent flu and I was truly cured in 48hrs.
My Ox Tails and Osso Bocco stews are done in 50- 70 minutes compared to nearly 3 – 5 hrs
I’m having a freezer delivered Thursday because I’m running out of room for my bones and bone broth! It’s the best. I can’t wait to my hand pork bone broth! I have a pig foot, tail, and assorted shoulder, ham hocks, and rib bones all ready!
Where do you get all your bones?
Karyn, you can purchase bones from local farms. Find a couple farmers markets in your area – there are almost always small businesses there who sell the meat from their farms. Contact them directly to inquire about purchasing the bones.
What is your recipe for the herbaceous green soup please