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)
I recently bought an Instant Pot SMART and I’m amazed by it! I always thought pressure cookers were for cooks who didn’t have the time to do it the ‘right’ way (i.e. a nice long braise). I’m amazed that the recipes I used to braise come out way better in the IP! The meat is tender but also so juicy. I’m having a ball with this thing! Great for rice, grains, and beans of course … Just made a great soup with a ham hock and dry beans. So many other fun things I can’t wait to try. You can make ricotta cheese with this but also I think I can use the bluetooth feature to make some of my other fresh cheese recipes more easily! I’m very excited about this purchase, I’ve only had it about a month. Have a great time experimenting and collection recipes to adapt …
I’ll be curious to hear how you do with cheese making in the IP. I tried to program my Smart IP for some cheese making recipes, but it didn’t work well. ?
Nancy: Could you tell why it didn’t work? I haven’t done it yet, can you tell me anything that might help? I know that the temperature sensor is at the bottom, that could be a problem I guess …
Thank you so much for writing this post!
You’ve gone above and beyond answering my question that I posted on your insta pot review.
I was actually quite sure I would pass on these appliances because I believed it was ‘risky’ in terms of food quality.
You’ve converted me with logic and reasoning! I am excited to find a good sale and give this gadget a go.
$115 on Amazon!
I’m glad you researched this because long ago I heard that pressure cookers were not good to use and that’s what held me back from getting an InstaPot. Thank you,
Thank you, was thinking about this when i read your instapot post!! Makes sense 🙂
Hilda M Smylie
I have been feeding my 3 scotties with home made dog food at least once /day. I love the pressure cooker for quick cooking chicken breasts, with or without bones.No added onion to the broth so I can use the chicken breasts for anything I want. I usually cook 4-5 at a time and store in a container in the ref. I can then use the cooked chicken breasts for quick soups, chimichangas, salads, stir fries, plus for my dogs. So much better than the canned chicken I used to buy Takes 10 mins. to cook and 10 mins to de-pressurize.My other favorite is for corned beef and cabbage but that is not so frequent.I have a fagor pressure cooker with 2 sizes of pans and I use a gas stove. I have not tried rice in it because I have an excellent rice cooker and I use that to cook brown rice with veggies for the pooches.
Thanks a bunch for writing this Katie. I use pressure cooking on everyday to cook different kind of lentils for my whole family. I was always concerned about pressure cooking but never did the research on this. So glad that you did the research for all the other families. Thanks!
I also use the pressure cooker mostly for bone broth.I use the slow cooker in the past but now sice several month with the pressure cooker I get the best bone broth ever.
I am concerned about AGEs. If the temperature is only 250 I would think we’d be fine, but I’d be curious to see if pressure (which I think is configurable) or brand affect temperature. Have you experimented with different settings and temperature?
I have never been able to understand how a pressure cooker
can make great “gelatin” bone broth?
The term “pressure” to me means, that the minerals/gelatin etc.
can’t be released from the bones into the water.
It must work because several posts here love it.
Does it produce thick gelatin once refrigatrated or is it
a runny liquid broth?
I do it in a slow cooker for days and get great gelation.
If pressure cooking produces the same thick
gel as to a runny liquid broth, I’m buyin’
a pressure cooker!!!
Since I use the pressure cooker for making stock I can eat my stock with fork and knife.
Mine turns out perfect! It really ia almost like jelly ?
How do you adapt a “traditional” recipe to cook properly in the InstantPot. I just got an IP for Christmas and am a little lost. I have done beans and rice successfully, but I make soup every week and would love to know how to adapt my soup recipes to cook in the IP.
I would google for a similar recipe, for example “cheddar broccoli soup in pressure cooker” and follow the heating guidelines using your recipe measurements.
This is helpful: https://www.hippressurecooking.com/pressure-cooker-recipe-converter/