8

votes

Cast Iron -> Really Safe?

Answered on August 19, 2014
Created September 20, 2011 at 4:24 PM

Cast-iron cookware seems to get a lot of paleo love. I have trouble understanding how it could really be healthy. But perhaps my concerns can be dismissed. (I would love to have a healthy non-stick option).

1) The seasoning process seems to involve oxidized, polymerized oils, unsaturated fats and high temps even preferred. Regardless of type of fat used, it seems to very much be a chemical breakdown-free radical sort of process. Exactly what we WOULDN'T want going on while cooking. So are we confident the resulting seasoning layer does not leech harmful bits into our food during normal cooking? Is anything 'bad' gone after the seasoning process or safely 'locked away' in some sense?

2) The typical process of using it seems to involve intentionally leaving oil on the pan in between uses. Won't this go bad, even saturated fats? And even what we think of as predominately saturated fats would probably be some % unsaturated, hence definitely go bad.

3) Similar to #2, wouldn't old food bits tend to be left, perhaps in very small quantities, due to limited cleaning methods. (Perhaps not an issue with thorough cleaning, but that tends to go against protecting the seasoning)

4) I've seen it mentioned that iron itself can act as a catalyst to increase fat oxidation.

5) Have also (once) seen the claim that the form of iron we would get is not the kind our body can use (and potentially harmful). No idea if there is any merit to this.

Any thoughts?

361bc16cfdad25411a6f93e10c45aadc

on February 24, 2012
at 03:14 PM

I'm interested in having the oxidation part of the question answered..

F52b51135f2c47eb46c986fdc9760b9b

(180)

on October 11, 2011
at 01:40 PM

nice article, very useful.

03fa485bfd54734522755f47a5e6597e

(3944)

on September 21, 2011
at 11:57 AM

My mom's egg skillet has about 1/4- to 1/2-inch of lard in it. Makes it easy to get the whites cooked and leave the yolks runny -- just swish some of the hot grease over the top of the eggs as they're firming up on the bottom. Now and then she cooks french fries in it, which she says cleans the oil, because the potatoes gather up all the tiny burned bits of meat and egg that have accumulated.

65660697ed243c7980725fd014eb00e0

(494)

on September 21, 2011
at 02:13 AM

Thanks for linking this, Jack! I hadn't seen it before and there's a crap ton of good info in there.

Aead76beb5fc7b762a6b4ddc234f6051

(15239)

on September 21, 2011
at 01:18 AM

my eggs slide right out of my great grandmas griswold cast iron pan. if i was evacuating, that would be the first thing i grabbed running out the door. it never sees any water, and was seasoned for the first 40 years of its life with bear grease.

77877f762c40637911396daa19b53094

(78467)

on September 21, 2011
at 12:20 AM

They do it in restaurants, too. Keep using it until it gets too brown.

77877f762c40637911396daa19b53094

(78467)

on September 21, 2011
at 12:19 AM

Matthew, we don't need no fancy science talk round these parts. And no goldurned logic, neither!

0bc6cbb653cdc5e82400f6da920f11eb

(19245)

on September 20, 2011
at 08:38 PM

Bacon grease is mostly unsaturated fat (about 60% unsaturated).

0bc6cbb653cdc5e82400f6da920f11eb

(19245)

on September 20, 2011
at 08:36 PM

Bacon grease is mostly unsaturated fat.

8e1876a74536739ecf7bef97d5d97b76

(747)

on September 20, 2011
at 07:52 PM

I thought my mom was the only one that reuses the oils for days

77877f762c40637911396daa19b53094

(78467)

on September 20, 2011
at 07:39 PM

Good luck with that. You can pull it off with a very well sesaoned skillet with a good amount of oil/fat. I consider it a true test of how well seasoned cast iron is, though. Let us know how it turns out. I always "mini-season" my pans after I use them. Scrub 'em out with a brush, rinse (no soap of course!), then apply a small coat of fat and let it sit on the stove on low for at least an hour.

77877f762c40637911396daa19b53094

(78467)

on September 20, 2011
at 07:28 PM

Never tried it, because bacon grease works so well. Sausage grease is a close second, but I bet beef tallow would work pretty nicely, too. I doubt pioneers using cast iron skillets used Flax oil. They used lard, bacon grease, or some other animal fat. And to me, that is the gold standard.

Da8e709acde269e8b8bfbc09d1737841

(1906)

on September 20, 2011
at 06:49 PM

Flax oil is considered the gold standard for seasoning cast iron.

C4134ed417dbc0a6b79ab2cee32632d3

(1811)

on September 20, 2011
at 06:41 PM

Joy, everyone used to do this with lard/dripping before switching to unsaturated fats. There's a thread about it somewhere (on phone, sorry).

D1728f99db66ff91d695a6df5cd38b02

(1368)

on September 20, 2011
at 06:02 PM

Uh Oh is it bad to keep oil after it has been used once? Is it bad to leave food in the oil?! Is it bad to leave oil in the frying pan for another use the next day??!!! I'm in deep trouble if it is

1ccc0b0b7a756cd42466cef8f450d0cb

(1801)

on September 20, 2011
at 05:42 PM

I found that emperor beef tallow worked pretty well too.

6229cd9a7ca9882590259fae022e2647

(3209)

on September 20, 2011
at 04:44 PM

Hmmm...I wonder if my Magnalite cookware is safe.

C1c86f42410cd4788bd9c5cf801dcd8f

(2246)

on September 20, 2011
at 04:39 PM

Don't you dare take away my Cast Iron pans... really what does that leave us with. Interesting question however.

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7 Answers

5
77877f762c40637911396daa19b53094

(78467)

on September 20, 2011
at 05:13 PM

Who told you to season with unsaturated fat? Bacon grease is the king when it comes to seasoning cast iron cookware!

All hail king bacon!!!

77877f762c40637911396daa19b53094

(78467)

on September 20, 2011
at 07:28 PM

Never tried it, because bacon grease works so well. Sausage grease is a close second, but I bet beef tallow would work pretty nicely, too. I doubt pioneers using cast iron skillets used Flax oil. They used lard, bacon grease, or some other animal fat. And to me, that is the gold standard.

0bc6cbb653cdc5e82400f6da920f11eb

(19245)

on September 20, 2011
at 08:38 PM

Bacon grease is mostly unsaturated fat (about 60% unsaturated).

0bc6cbb653cdc5e82400f6da920f11eb

(19245)

on September 20, 2011
at 08:36 PM

Bacon grease is mostly unsaturated fat.

77877f762c40637911396daa19b53094

(78467)

on September 21, 2011
at 12:19 AM

Matthew, we don't need no fancy science talk round these parts. And no goldurned logic, neither!

1ccc0b0b7a756cd42466cef8f450d0cb

(1801)

on September 20, 2011
at 05:42 PM

I found that emperor beef tallow worked pretty well too.

Da8e709acde269e8b8bfbc09d1737841

(1906)

on September 20, 2011
at 06:49 PM

Flax oil is considered the gold standard for seasoning cast iron.

1
32f5749fa6cf7adbeb0b0b031ba82b46

(41747)

on September 20, 2011
at 07:34 PM

In a properly seasoned pan, the oil shouldn't ever see the raw iron surface, only polymerized cooking oils from previous uses should come into contact with food. Minimal iron should leech and the catalytic effects (if any) should be minimal.

1
Af1d286f0fd5c3949f59b4edf4d892f5

(18472)

on September 20, 2011
at 06:14 PM

Don't forget to check out Jae's cast iron thread with a lot of info on how to do it. I recently bought 4 unseasoned pans of all sizes and haven't started the process but I will be digging into this pretty soon...

http://paleohacks.com/questions/5031/how-to-season-maintain-a-cast-iron-skillet#axzz1YW9y4sNK

65660697ed243c7980725fd014eb00e0

(494)

on September 21, 2011
at 02:13 AM

Thanks for linking this, Jack! I hadn't seen it before and there's a crap ton of good info in there.

1
E34fbfa1bca9ae970c9c7313bf9de9f8

(1436)

on September 20, 2011
at 05:58 PM

I think stainless steel is superior in most situations. Stainless steel is easy to keep clean and I don't need the extra iron in my food. It heats quickly and evenly especially if you get 18/10. Also, you can't do acidic sauces or reductions in cast iron.

I do like a searing a good steak on my cast iron, though.

1
C6fefe21174920b7e6f2a7f4f37f5291

(20)

on September 20, 2011
at 04:54 PM

the production of a crosslinked polymerized surface (seasoning) on cast iron is well documented; but if it truly concerns you, consider purchasing a stainless steel All-Clad pan for your cooking; when new they are polished to an almost mirror finish, which helps the food slide right out. drawback is you must use nylon/silicone/bamboo/wood cooking implements, as metal spatulas and such will cause scratches, which will impair the 'non-stick' -ness by giving the food molecules something to catch on. hope that is some kind of helpful!

F52b51135f2c47eb46c986fdc9760b9b

(180)

on October 11, 2011
at 01:40 PM

nice article, very useful.

0
345c1755efe005edd162b770dc6fb821

(8767)

on September 20, 2011
at 07:35 PM

I just bought two cast iron pans, yet to use or season them, but plan on using bacon!!! I remember an old boyfriends greek grandmother who cookesoakot and used her cast skillet but obviously not for everything. She also prided herself in her oil mix left sitting in the pan, French fries made in this pan were to die for.

I have mostly stainless pans now 18/10, eggs seem to be the only thing you you can't do in them. I'm hoping the tiny cast pan I bought will work well for eggs.....

03fa485bfd54734522755f47a5e6597e

(3944)

on September 21, 2011
at 11:57 AM

My mom's egg skillet has about 1/4- to 1/2-inch of lard in it. Makes it easy to get the whites cooked and leave the yolks runny -- just swish some of the hot grease over the top of the eggs as they're firming up on the bottom. Now and then she cooks french fries in it, which she says cleans the oil, because the potatoes gather up all the tiny burned bits of meat and egg that have accumulated.

8e1876a74536739ecf7bef97d5d97b76

(747)

on September 20, 2011
at 07:52 PM

I thought my mom was the only one that reuses the oils for days

77877f762c40637911396daa19b53094

(78467)

on September 20, 2011
at 07:39 PM

Good luck with that. You can pull it off with a very well sesaoned skillet with a good amount of oil/fat. I consider it a true test of how well seasoned cast iron is, though. Let us know how it turns out. I always "mini-season" my pans after I use them. Scrub 'em out with a brush, rinse (no soap of course!), then apply a small coat of fat and let it sit on the stove on low for at least an hour.

77877f762c40637911396daa19b53094

(78467)

on September 21, 2011
at 12:20 AM

They do it in restaurants, too. Keep using it until it gets too brown.

Aead76beb5fc7b762a6b4ddc234f6051

(15239)

on September 21, 2011
at 01:18 AM

my eggs slide right out of my great grandmas griswold cast iron pan. if i was evacuating, that would be the first thing i grabbed running out the door. it never sees any water, and was seasoned for the first 40 years of its life with bear grease.

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