In my Instant Pot FAQ, I have the following question:
Q: What about natural pressure release? When the Instant Pot finishes cooking, it switches to Warming mode – is that OK with a natural pressure release? Or should I cancel it?
A: Cancel warming mode to speed up natural pressure release.
I was reading the Instant Pot Community Facebook group, and saw a heated debate: Keep Warm and Natural Pressure Release. One side was strongly in the “warming mode doesn’t matter” camp, the other was in the “turn warming mode off” group - and used my FAQ post as evidence.
After reading the debate, I started to wonder - am I wrong about warming mode? I assumed that turning off the heat would speed up the natural release - that the pot would lose heat quicker without any heat being added by warming mode.1 The argument against cancelling Keep Warm mode is the pot’s thermostat. Warming mode keeps the temperature between 145°F and 172°F, so it won’t turn the heat on until the temperature drops to 145°F. That’s well below the temperature where pressure will release.
I ran a quick test - I set my IP-Duo and IP-Smart next to each other on the counter, added a quart of water to each, set them for 3 minutes of high pressure cooking, and waited for it to finish. They both came up to pressure and counted down the three minutes at about the same time. I cancelled the Keep Warm mode on the IP-Smart, and waited for the pressure indicators to drop. Much to my surprise, the IP-Duo finished manual pressure release about five minutes before the IP-Smart!
But…is that a valid test? Maybe there is something about the IP-Smart that slows down cooling. To reduce the variables, I ran the test over and over again with my IP-Duo, a quart of water at high pressure for 3 minutes, and alternated leaving Keep Warm mode on and off.
Sitting and watching natural pressure release is only slightly less interesting than watching grass grow. So, instead of babysitting each run, I set my Phone on a tripod and filmed it using time-lapse video mode. Here are the time-lapse videos from the third run, side by side:
You can see them finish within a minute of each other - this is consistent across all the tests. Sometimes Keep Warm mode finishes first, sometimes cancelling it does - but the difference between them was always less than a minute, and it kept moving around as to which was faster. 2
In summary...
Keep Warm mode doesn’t affect natural pressure release. It finishes at about the same time either way, so don’t bother canceling it. I was wrong in my Instant Pot FAQ; I’m sorry I gave you bad information. (And, of course, I updated the FAQ to match this new info.)
Kristina P says
Thank you so much for taking all that time to explore this empirically. I was really wondering why some recipes said to turn the Instant Pot off, while others allowed the natural release to happen on keep warm. I thought it had something to do with whether or not the meat would overcook or get dry or whatever the reason may have been. Thank you for solving that it's irrelevant. I can leave the Instant Pot on because, as Ed Bragg pointed out, I want the count up for the natural release. Way to go, Mike! Second time your site has come through for me. (Awesome cheesecakes, by the way!)
Mike Vrobel says
You’re welcome!
dave divelbiss says
thank you for this! tip given,
and with heat on, you get the bonus of the timer function!
Renee says
Thanks very good info!
Melody says
Thank you for your time and trying to answer this question. Appreciate all your info.
Marilyn says
How great to have this very vital question and have such a valid response. I think my life can go on enjoying my Instant Pot even more. Trying a bread pudding this afternoon and will just let the keep warm mode take care of the natural release.
Franck says
Great information ! Thanks a lot !
Liane says
Thanks, Dad!
Mike Vrobel says
You're welcome!
Charlene says
I’ve been searching for an answer to this question for about a year. Your detailed and well reasoned explanation makes perfect sense. Thank you!
Mike Vrobel says
You're welcome!
Norma says
Thanks for testing I too am a new user and thought I read you had to cancel keep warm so Im glad to know it is not necessary
Norma Burroughs says
Love that there's even a dad who's got this figured out ...Whoever used to think that only Mom's knew all about cooking appliances were not really noticing how many great dads there out there today.. Keep it up Thanks for your "dads cook dinner.com Wishing you the Best...
from Longmont Colorado...
Pam Heiser says
I am so thankful for people like you who post answers to these kinds of questions! There is no helpful information in the user manual that addresses what you explained so thoroughly here. I am using my IP for the first time and using all the online help I can get. Thank you! Misty has it right about the heavens shining down...
Kia says
Agreed!! I was searching everywhere to this answer because everywhere talking about natural release is involving the older models. Thank you so much!!
James Ortiz says
Not all heroes wear capes.
Kate Bates says
Great info! I was sure that the natural release would be greatly delayed by the Keep Warm mode. Duh. Makes sense that they thought of that. Thanks for doing the test.
Ed Bragg says
No one mentioned the best feature of keep warm mode, vs. turn off. If you turn it off and recipe specifies X-minutes of natural release, a timer must be set. Keep warm begins counting up when cooking time is up. Very helpful if you need to know how long to let it sit while pressure is releasing.
Not sure release time is critical, but many recipes call for 10-20 minutes, and if not naturally released, to release it. Whatever - In keep warm, I don’t have to set a timer for that, if it’s important.
Terry says
Thanks so much for the clarification! I was getting annoyed at having to turn off the "keep warm" setting all the time because I didn't want things to overcook. Now I know I don't have to worry!
pam Craig says
I just got my instant pot pressure cooker and was reading the recipes. the recipe for kalua pork has only 1/2 C of water and !T of smoked liquid in it yet it has 4 pounds of pork. I thought he rule was to have 2 C of some type of fluid???? I am confused! please help
Mike Vrobel says
See the "minimum liquid amount" question in my Instant Pot FAQ: https://www.dadcooksdinner.com/instant-pot-frequently-asked-questions/