Skillet cornbread with a crust you can hear

Cornbread in a tin is a cake. Cornbread in a preheated cast iron skillet is something else entirely: the batter hits fat at 400 °F and sets instantly into a shell that cracks when you cut it. That transformation is thermal mass doing a job nothing else in your kitchen can do.

What you need

• A No. 10 or No. 12 skillet. Nothing else, and definitely not a tin.
• 240 g stone-ground cornmeal, medium grind
• 60 g plain flour
• 2 tsp baking powder, 1 tsp bicarbonate of soda, 1½ tsp fine salt
• 400 ml buttermilk
• 2 eggs
• 60 g melted butter, plus 3 tbsp bacon fat or a neutral oil for the pan

Method

1. Put the empty skillet in the oven and set it to 450 °F. Leave it there for a full twenty-five minutes after the oven says it is up to temperature. The oven reaches 450 long before 7 lb of iron does, and this is the step that decides whether you get a crust.
2. Whisk the dry ingredients in one bowl. Whisk the buttermilk and eggs in another. Combine, then stir in the melted butter. Stop the moment it comes together — about fifteen seconds of stirring. Lumps are fine.
3. Pull the skillet out. Add the bacon fat and swirl it: it should shimmer and start to smoke within three or four seconds. If it does not, the pan is not hot enough and you should put it back.
4. Pour the batter in all at once. It should hiss loudly and the edges should visibly set before the pan is back in the oven.
5. Bake 20 to 24 minutes until the top is deep gold and a skewer comes out clean.
6. Rest it in the pan for ten minutes, then turn it out. Do not skip the rest; the base is still cooking on residual heat.

Why the heavy pan matters here

When cold batter hits a thin pan, the pan temperature collapses and the batter poaches in its own moisture before it can set. On our bench, a 4.5 mm cast iron skillet loses about 38 °F when the batter goes in. A 2.6 mm clad pan loses over 160 °F. That difference is the entire recipe.

Variations we actually make

Fold in 150 g of grated sharp cheddar and two finely chopped jalapeños with the wet ingredients. Or brown 100 g of bacon in the skillet first, tip the bacon into the batter and leave the fat in the pan to preheat.