Some posts are sexy and mouth-watering but this post, The Instant Pot® Liquid Myth – (How much liquid do I need?), is completely practical. If you own an Instant Pot®, this is just the kind of useful information you need to understand the concept of cooking vegetables you and your family will enjoy time and time again.
The Instant Pot® Liquid Myth
Recently, a student at one of my Instant Pot® classes asked me why she had to use 2 cups of liquid when she was cooking vegetables. A week later, someone else asked me about using 1 cup of liquid. Instant Pot® cooking techniques and information inconsistencies run rampant across the internet and I think it’s important to de-mystify these kinds of liquid conundrums. A good meal often depends upon it.

Instant Pot® Recommendations
It’s important to note that Instant Pot® has changed its official recommendation from 2 cups of liquid for cooking all foods to just 1 cup. Those with older models and old issues of the brand’s manual and recipe booklet may be following outdated information. In fact, a student at a recent class told me as much; she’s been cooking all foods with 2 cups of water because that’s what the booklet instructed. She grew to like the leftover liquid from cooking veggies because it was there but it certainly didn’t improve the flavor of her food. (If you do end up with a lot of leftover liquid, you can save it for soup or use it for other cooking, depending upon what it was that you were cooking.)
Let’s clear up this myth. While 2 cups of liquid is certainly way too much for cooking most foods, even the new 1 cup recommendation may be too much as well. It really does depend on the type of food being cooked.
Cooking Vegetables and Dried Beans in the Instant Pot®
In my book Vegan Under Pressure, I provide cooking charts for liquid measurements and many people consider the cookbook the “vegan or plant-based cooking Bible.” For some whole grains, 2 cups of liquid might be just right and the often-suggested water-to-rice 2:1 ratio is just too much liquid as well. In fact, I can’t think of any type of vegetable that requires 2 cups of liquid; even if you’re making a lot of them. For instance, when making Garlic Parsley Mashed Potatoes with just 4 medium potatoes, you need only 1 cup of liquid in which to cook them. Most other vegetables need even less.

Vegetables like bok choy and mushrooms naturally contain a lot of liquid and do not need much additional water for cooking. The same goes for summer squash and zucchini. Too much cooking liquid makes for a soggy side dish!
Steam potatoes, sweet potatoes, and winter squash on a rack over 1 cup of water.
For dried beans, soaking 1 cup of beans in 2 to 3 cups of water is sufficient for rehydrating the beans in order to cook them. Drain the beans and cook them in 1/2 to 3/4 cup of liquid. A lot of people think they need to cover the beans with 1 to 2 inches of water over them in order to cook, but this results in overcooked, mushy beans. The Instant Pot® does not cook by boiling; this pressure cooker cooks with super heated steam and that is why the lesser amount of water is enough.
In my experience, cooking vegetables in the Instant Pot®, using 1/2 cup of liquid is plenty and for some vegetables this may even be too much. You may be asking, “so how do I know?” and the answer is: there is no magic number. If there is a number, 2 cups of water is certainly not it!
I hope my explanation is helpful and that you experiment with the water-to-vegetable ratio using my guidelines. If you are new to the Instant Pot®, or any other pressure cooker, please join my Instant Pot Beginners Veg Support Facebook Group for tips, tricks, recipes, and cooking chit-chat.
Happy Instant Pot® cooking!
Whenever I cook large baby Bella mushrooms my IP will spew steam and some water upon quick release. I noticed this when I added just 2-4 T water for cooking. Today I added NO water. I washed the shrooms drained them – and really let them drain 10 minutes. Still, I had steam and water spitting out. My cook time was 2 minutes. Just FYI – this has happened with 2 different seals, so I don’t think that’s it. I do cur these into quite large pieces because I enjoy them chunky. I’m beginning to think the IP may not be the ideal way to cook these. I have done them stovetop but that requires tending.
I am sorry to hear this. I cook a lot of mushrooms and don’t have issues. Usually, I only cook a minute or two. Maybe it has to do with how full your pot is. Hard for me to know.
Does this steam problem happen with other foods? If not, how about if you do a controlled quick release? OR just do a natural release and then there won’t be any steam issue.
I hope that you are able to figure this out.
Hi Jill,
I finally got an instant pot, 8qt.Pro. I’ve been using your pot in pot recommendations from a Chef AJ video with my stovetop pressure cooker and had great success.
However, my first Instant Pot attempt pressure cooking 2 cups soaked pinto beans in 1 1/4 cups of water on high for 10 minutes resulted in the burn warning. The water was level with the beans. The beans were not buttery. I only used a bay leaf in the cooking water.
My second try, 2 1/2 cups soaked/drained pinto beans, 1 1/2 cup water, and a warning with a 12 minute cook on high. I used a salt-free seasoning in the cooking water.
Thankful for the warning as I rescued both batches with more water and time.
Do you spot any glaring errors in my technique?
Do any of your cookbooks address this type of newbie experience with the Instant Pot?
Thank you
The newer 8 quart pots seem to present their own challenges with burn warnings and the amount of liquid. You DO need more in the 8 quart but I don’t have one so I am not sure how much. I would go with a minimum of 3/4 cup per cup of dry beans that have been soaked. You can go up to 1 cup and see what happens. In their infinite wisdom, the Instant Pot company added the burn warning, which sometimes alerts you to a real issue and sometimes just stops the IP from working well.
Please keep trying, paying attention and writing down what works with your new 8 quart IP.
I see Instant Pot recipes for frozen shrimp say to use 1/4 cup water or broth. Perhaps there’s enough water in the ice around the shrimp? Maybe I’ll compromise for my first try, and use 1/2 cup.
This is vegan/plantbased site so I know nothing about shrimp and liquid. And it isn’t my recipe. Just be aware that recipes that aren’t tested or well written can ruin your ingredients. Good luck.
I was taught by my Asian mom to use a 1:1 ratio of rice (jasmine)to water. With the Instant Pot, I usually use a little less water than 1:1. The rice cooks perfectly.
If you read my post on “perfect” rice, you will see that we all like our rice a different way. I always suggest doing what works best for you.