How much liquid do I need to pressure cook?

While many pressure cooker manufacturers will tell you that you need a minimum of 1 or even 2 cups of thin liquid to pressure cook, this is not always the case. In short, you need just enough liquid to build the steam for the pot to go under pressure, this can be anywhere from a few Tablespoons to 1/2 cup or so. The volume of your pressure cooker can make a difference in the amount of liquid you need, but in most recipes or cooking applications the amount of difference is so small that it isn't anything to worry about. The MOST important thing to consider when determining the amount of liquid you need is what you are cooking and if the food will absorb or release liquid or do neither. 

For example, I have pressure cooked with ZERO added liquid and it worked just fine BECAUSE I was pressure cooking apples for a pie filling and apples give off a ton of liquid as soon as they start to cook. If you want to see how I did the pie filling, here is the recipe: Homemade Apple Pie Filling. 

Pressure cooking without ANY added liquid is very rare though, most of the time you will need at least 1/2 cup of a THIN liquid to build the steam needed for pressure cooking. Here is a table to help you determine how much liquid you need based on what you are cooking. Please note, these amounts are ONLY guidelines and not exact measurements. There are always variables and one of them is if you are cooking directly in the inner pot or pot in pot. Another variable is other ingredients in the pot. For example, if you are cooking pasta with a thicker sauce like a tomato sauce, you may need 2 cups per every 8-12 ounces of pasta instead.