While researching about pressure cookers, I found a comment in a review that says:

As with all aluminum pressure cookers, the metal will react with some foods and can overheat if you are not careful [...]

This is news to me. Further research seems to mention only a couple of salient points:

  • Aluminium is very reactive in general
  • Acidic foods may react in a pressure cooker

Since I don't see myself puting lemons or tomatoes in a pressure cooker, I'm really at a loss as to why this could be an issue.

What foods commonly react in an aluminium pressure cooker, and what do I do about it?

  • baking soda is one of the most corrosive to aluminum among all food ingredients. Oct 27, 2017 at 15:10

2 Answers 2


Aluminum isn't exactly toxic or harmful to the same degree as lead, but it's not exactly good for you either. And as you've identified, aluminum is fairly reactive. Higher acidity, salinity, and cooking time will all contribute to further reaction and absorption in any aluminum cooking vessel (or utensils for that matter).

This is an issue for three primary reasons:

  1. Absorption of aluminum is, as noted above, not necessarily healthy.
  2. Absorption of aluminum can result in a metallic flavor in your food, which is generally unpleasant.
  3. Absorption of aluminum into your food also corrodes the cooking vessel.

That third is probably of the most concern here, since you're talking about a vessel that's under pressure when in use. Sufficient corrosion and the resulting structural weakness could (in very rare cases) cause a rupture and sudden pressure release, i.e. hot stew explosion. This would take a long while to occur, and you'd almost certainly notice the corrosion on the inside of your vessel before it became truly dangerous, but this type of problem is exactly why modern pressure cookers have such fancy pressure-sensitive locks and come with warnings all over them. They can pop if abused, and they do this in your kitchen, possibly while you're nearby.

So, extended cooking of certain acidic items (what if you wanted to make, say, tomato sauce in your pressure cooker?) could be dangerous with long-term use, hence the warning. Such foods will also contain more aluminum than they would otherwise, and taste like it as a result. Here's a thread with information on the general pH levels of common foods, which may help you identify specific items of concern.

Another good way to avoid this is to select a stainless steel model instead of aluminum. Stainless is more expensive and doesn't heat up as quickly, but it's not as reactive as aluminum either, so there's less concern when cooking acidic ingredients over a long period. Here is a decent buying guide with comparison of features and some more specific recommendations.

  • If I understand your first paragraph right, you're suggesting that aluminium is a poor vessel for pressure-cooking because of higher cooking times. Is that right? Then why, coupled with your third point, is it such a common choice for pressure cookers? Is it just plain economics?
    – ashes999
    May 25, 2014 at 16:36
  • 2
    Specifically, aluminum cookers can degrade faster than stainless steel if used repeatedly to cook acidic ingredients. Most home cooks will probably not do this often enough to cause any issue, but it's possible. Aluminum is still commonly used because it's cheap, lightweight, and has better thermal conductivity compared to stainless steel, so it heats up more quickly. So yes: economics.
    – logophobe
    May 25, 2014 at 21:03
  • 1
    Alternatively, place the dish being cooked in a stainless steel container that fits neatly inside the pressure cooker.
    – Buddho
    May 28, 2015 at 21:50

Aluminium may mix into the food if heated for a long time and lot of metals do. I always cook in aluminium pressure cookers with stainless steel containers inside so that will serve both purposes or using aluminium for getting high temperatures and also not contaminating the food since it doesn't directly get in contact with the food.

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