This archived forum used to be called 'Peatarian' (in reference to Ray Peat).

metal absorption from stainless steel cookware

Pretty much any stainless steel kitchen stuff you buy is going to be 18% chromium and either 8% or 10% nickel. I recall Peat mentioning that it's best the steel be magnetic, indicating a lower nickel content. Well, anything you'll realistically buy will be the same nickel content of maybe 9%. Maybe if you deliberately bought some chintzy dollar store Chinese made crap the metal is worse, but other than that it's all the same 304 grade stainless steel.

I use a stainless steel digital pressure cooker constantly, even with acidic stuff. Anyone got info on toxic metal absorption from cooking with modern stainless steels? I would imagine any of the chromium, iron, or nickel could be a problem in the long term. I'm not too worried about it, just curious.
asked Mar 27, 2015 by 4a552f55cbb9

2 Answers

After using them a couple of times metal migration is negligible. Choose a high quality product, they use better steels that cause less metal migration.

Glas ceramic cookware could also cause migration, I have not seen analyses that those are really toxin free when used for cooking.

Magneticity is a bad indicator of nickel content. There are non-magnetic 18/0 pans and magnetic 18/10 pans, the extend of magneticity also relies on other factors than nickel content.
answered Mar 28, 2015 by Bukowski
There really aren't any toxic compounds in high quality Pyroceram / Calexium cookware (original corningware/visions) that could leach out. It's mainly silicon dioxide and boric acid with a few trace minerals.

Cheaper glass ceramic is a different story of course.

"After using them a couple of times metal migration is negligible."

What about scratches on the bottom of your pot that occur during stiring or cleaning?

The small amounts of metals leaching into your food might be negligible if you consider all the other toxins we are exposed to daily.

I personally would still try and avoid it
I started freaking out about that a while ago.
Tried out different glas cookware but most of them broke after a few weeks.
I have been using the glas pots from "visions" for almost a year now, completely indestructible.

Not advertising for the shop or anything, it's just the first link that came up. I bought them on german amazon.

If you are thinking about getting something i can recommend the 1l saucepan with the little dent for pouring stuff out.
For the bigger pots you need to use a ladle and cant just directly pour it onto your plate without making a mess (i guess because they are a lot thicker than regular stainless steel pots)
answered Mar 28, 2015 by skally
edited Mar 28, 2015 by skally
There is no such thing as a ceramic or glass pressure cooker.

Those look nice. You can also get oven and microwave safe ceramic casserole dishes for about $20.

I'm more curious about What hard data is there that stainless steel is something worth worrying about at all?
High quality Pyroceram / Calexium ceramics is a relatively complex process that has been around since the 50's.

Using some cheap off-brand chinese cookware with possibly toxic components just to save $10 seems unwise.
Also like I said, I've tried quite a few different ones. The cheap stuff will blow up at some point, sending shards flying through your kitchen. Pretty much guaranteed.

What do you use the pressure cooker for?

Like I said above, the metal leaching out of stainless steel is probably negligible if you're looking at the bigger picture. Just living in a large city will expose you to a greater amount of toxins in the air than your pot could ever leach out.
No studies to ease your mind, sorry
I use the digital pressure cooker for rice and potatoes and tough cuts of meat. It's super convenient because you can set it and walk away from it for an hour or more with no worries. The food will be ready and waiting.