Cast Iron isn't a good conductor

For all of the great benefits of cast iron for skillets, flat tops, etc. One thing that I overlook is that it doesn't actually conduct heat very well. It has great thermal capacity, but it needs careful treatment if you want even cooking temperatures.

This thought came about when I was making the excellent English Muffin's from Stella Parks' book "Bravetart".  The muffins had all the flavor, but weren't as puffy as I wanted. So I pinged Ms. Parks on twitter. She opined that the griddle was too hot, so the outsides set up before the middle could rise properly. Her recipe was quite specific - heat to 350F. If I had an electric griddle with a temperature control and a thermostat, it would have been easy. But I don't. So I had to guess using my cast iron flat top.

After that less than satisfactory outcome, it was clearly time for a gadget - in this case a surface temperature thermometer. I didn't want to go the full Alton Brown, but I did want to do a little experimentation. Off to AceMart (my local commercial kitchen supply store) where I found this jewel for $39.

Quite a revelation. I turned the burners to medium and started heating the flat top. First mistake! I had them too high. After 5 minutes the surface over the burners was about 375 and the middle was 280.

Turned burners down to their lowest setting. Waited another 10 minutes. Now the ends where the burners are was 410 and the middle was 375. Everithing far too hot for what I needed/wanted.

Moral of the story:

• Believe the experts when they say heat your cast iron slowly
• It gets up to temperature unevenly
• It's really hard to tell when it is at the temperature you want (unless you practice a lot)
• It's still the best surface for  stove top frying