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Got some very thick baked on oil inside of a Lodge dutch oven with an enamel lining. Avocado oil, baked on in a 500F oven while making bread. Can I save some time by just filling it up with warm water (~175F) and soaking for a while with a lye solution before I scrub off the oil? Will this damage the surface? The surface is not pristine, it's an old DO and saw a lot of use before I got it.

A lot of advice says use baking soda, which is pH 8.5. Lye is 13 but I know it will get rid of those polymerized fats.

I'm aware of all the danger of lye, I've used it to strip cast iron pans with no issue.

edit to clarify: thinking 1 tsp of lye powder to 3 qts of water. The real question is will any concentration of lye destroy enamel?

jcollum
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    What concentration of lye? A weak lye solution will be the same PH as a strong baking soda solution. – GdD Mar 13 '23 at 09:20
  • @GdD Makings such a weak solution of lye is both impractical and unnecessary. I worked the numbers out - to match a baking soda solution (pH 8.3), you need a 2 micromolar lye solution. That's 1.6 grams of sodium hydroxyde to 10 000 liters of water. It is doable with a household precision scale and without using up a year's worth of water supply (you'll have to do a multistep dilution), but it is tedious, has all the hazards of working with lye, and none of the advantages. Pretty much all uses of lye solutions I've seen in the household are in the range of tenths of percent to a few percent. – rumtscho Mar 13 '23 at 15:22
  • I was thinking 1 tsp lye to 3qt water. I guess the real question is will any concentration of an alkaline solution destroy enamel? – jcollum Mar 13 '23 at 15:23
  • whoa @rumtscho kitchen chemist in the house :) – jcollum Mar 13 '23 at 15:23
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    @jcollum I love the compliment, but I have to admit that everything beyond the gut instinct of "the difference between pH 8 and pH 13 is huge" was Google-fu. Turns out that Sigma Aldrich has a handy concentration calculator: https://www.sigmaaldrich.com/DE/de/support/calculators-and-apps/molarity-calculator. – rumtscho Mar 13 '23 at 15:31
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    It's unlikely to destroy the enamel, but it might damage it -- particularly creating a matte surface that would then make it into "superstick" cookware. – FuzzyChef Mar 13 '23 at 16:08
  • That surface is already pretty rough but it looks like it's not worth attempting based on the answer from @rumtscho below – jcollum Mar 13 '23 at 16:54
  • I will say that the recipe for nixtamalized corn I've seen says to use an enameled pot since it's non-reactive. I would imagine that means it's safe to use lye in an enameled pot. – Esther Mar 20 '23 at 18:48

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There are two reasons why I would not do it.

"Enamel" is not a single substance, but a class of substances. They can have different chemical properties, including corrosion resistance. And the enamels used in cookware are calculated to be resistant to what is usually encounterable in a kitchen. This is certainly not lye at pH 13 or above.

The Internet supports this intuition: for example, this site lists the corrosion resistance of enamels for different use cases, and while they don't have pots, pretty much all household items they list are formulated for the pH range of 2 to 10.

A second reason is that you don't only have to worry about the enamel as a substance. You have an enamel-lined pot, and these are very prone to chipping, and sometimes crazing. I would worry about lye "finding" these discontinuities in the enamel layer and attacking them. The iron of the Dutch oven itself shouldn't have any problem with it, but the problem would be the bond between the enamel and the iron. This bond is always weaker than either of the two materials, and anything that attacks there has a chance of destroying it and letting the lining layer peel off.

I will admit that I don't know whether the bond between iron and enamel can withstand lye, but seeing that it is one of the most corrosive substances a person will ever encounter, I wouldn't try it out on a pot I value.

rumtscho
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    The chart doesn't cover cookware, but some of the listed items are fairly similar. What's called "porcelain enamel" is actually a ceramic substance that is baked onto the iron or steel under high heat, so it should have a high degree of resistance to alkalis; but as the chart says, "high degree" isn't necessarily "pH 13". – FuzzyChef Mar 13 '23 at 16:05