15

I've been investigating getting an enamelled cast iron dutch oven and am surprised to find that most of them don't recommend going over 400-450°F (200-230°C) (most even on just the base, so the lid handle doesn't appear to be the only factor there).

Given that normal cast iron can go much higher and I wouldn't have expected that heat limitation on the enamel...what is it about the pots that causes that limitation? What risks are there in going above it?

Improve this question
1

3 Answers 3

Reset to default
4

They sometimes have plastic (cast phenolic resin) knobs on them that are only rated for just over 200°C (400°F), or other decorative trim that is not suitable for high heat due to deformation etc.

They do tend to start crazing (surface cracking) at over 200°C too

The enamel (a special soft glass powder) is fused on at over 800°C (1470°F)

You cannot melt glass enamel on a domestic stove. It would have to get to over 1100°C (2000°F) to melt!

Improve this answer
2
  • I don't think its the just handles, because as stated in the q - the recommended temps are for the base only even. In regards to the crazing, does this happen due to the difference of the thermal expansion between the two materials?
    – rfusca
    Sep 19, 2011 at 18:09
  • Surface crazing is certainly related to thermal expansion and would have something to do with it, but this usually happens when over heated above 200°C. But then again it does happen in enameled bathtubs with gas coliphonts, so it may happen as a result of temp and number of cycles
    – TFD
    Sep 19, 2011 at 20:59
4

I think its because of the difference of the thermal expansion between the two materials.

Since the ceramic has very low thermal expansion coefficient and cast iron seems to have a rather high coefficient comparatively, then the metals will start to pull apart too much at higher temperatures. The metal expands more than the ceramic under equal heat, so they start to separate and crack. Apparently, at just above the recommended point, it may start to cause the surface cracks which are common (thanks @TFD).

Improve this answer
3

The problem is, the enamel will melt at high temperature.

My brother once managed to ruin a pot when making ramen. (started to boil the water, forgot about it, all of the water boiled off, the pan heated up, the enamel melted, and then when we realized & cooled it off, the pan had fused to the burner)

Improve this answer
5
  • 1
    I'm just surprised the enamel is that low...craziness.
    – rfusca
    Sep 16, 2011 at 19:39
  • @rfusca I'm not sure what the actual temp was ... it was an electric stove on high, with no moisture in it, so it could've been much higher than 450F ... they likely have a safety window as ovens are inacurate & may have hot spots.
    – Joe
    Sep 16, 2011 at 21:15
  • 1
    Before the enamel hits Joe's extreme, high temps will also cause discoloration. It makes the pot look like something is burned to the bottom.
    – MeltedPez
    Sep 17, 2011 at 1:18
  • 2
    Wikipedia (take it with a pinch of salt) states that these dishes are fired between 750-800 F. I could see a empty pan on a stove getting towards that on high heat with a good stove. But that's a pretty hefty margin, double 400 to 800, for the oven (and the manufacturers specifically talk about oven temperatures).
    – rfusca
    Sep 17, 2011 at 2:17
  • 1
    @rfusca that would be 800°C (1470°F), must be a wikipedia error
    – TFD
    Sep 18, 2011 at 11:15

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.