Only once it has reached full pressure. Steam escapes noisily through the lid locking mechanism for about a minute first (escaping steam is used to engage the mechanism, which makes it fail-safe because without the mechanism engaged it will never reach full pressure).
>It has two pressure settings
Only on the more expensive model. Cheaper version only has the higher pressure mode. But I have the cheaper version and I have never wanted a low pressure mode. It seems redundant because it already has slow cooking mode.
2. True. But the difference when I bought it was around 25 dollars, so it seemed a worthwhile investment. I have used the low pressure to cook rice for some dishes which require the rice to be hard but cooked. I could do it in slow cooker mode, but it would take a long time.
FWIW, I've found that if you push down on the lid firmly once it starts venting steam in any quantity it will lock instantly.
1. Preserve the shape of the food being cooked. The older non-electric cooker would mush all the garbanzo beans or vegetables into a mash. When I cooked with the instant pot for the first time, I thought nothing was cooked fully because every vegetable and bean still were mostly in its original shape.
2. No noise. Non-electric cookers have the steam whistle to vent out excess steam which is noisy and annoying. Instant pot does not have that.
3. It has two pressure settings - lo and high pressure. When I bought it, very few of them offered this option.
Most electric pressure cookers come with a coated aluminum pot. Instant Pot was one of the first ones to offer a stainless steel container. This was the original reason I bought an Instant Pot.