barsoap , 3 months ago

To reseason cast iron, you need an oil high in poly-unsaturated fatty acids.

In other words: Linseed.

Though I wouldn’t go so far as to say “need”. Linseed works much better, builds a nicer patina very quickly, but pretty much any fat works. In practice mine is getting seasoned with olive oil because that’s what I have standing around in the kitchen.

Proper technique is much more important in practice: First and foremost heat empty, then add oil and fry, then clean, ideally without degreasing (boiling water and a spatula do wonders), then (if necessary) add a drop of oil and try to rub it off with kitchen tissue, then put back on the stove to dry and maybe polymerise a little. Always have that thin layer of oil otherwise the pan is going to rust.

You can have a perfect patina, if you don’t heat up the pan before putting stuff in there things are still going to stick. You can have practically no patina, if you bring up just a single thin layer of any fat up to its smoke point and after that add oil (so the thing isn’t completely dry) things aren’t going to stick.