A cast-iron skillet is not non-stick because of its metal; it is non-stick because of a resilient layer of cross-linked polymer chains bonded directly into the microscopic pores of the iron through extreme heat.
1. Why Flaxseed Oil Flakes
Internet lore frequently recommends food-grade flaxseed oil because of its high iodine value. In real kitchen practice, pure flaxseed oil cures into an excessively hard, brittle polymer film. Under the thermal shock of daily cooking, it fractures and flakes off in black specks.
Grapeseed oil is far superior. It contains a balanced proportion of polyunsaturated and monounsaturated fatty acids that polymerize into a tough, flexible film that adheres tenaciously to the iron substrate.
“Seasoning is not grease on metal; it is an oil chemically transformed into a tough organic polymer.”
2. The Micro-Thin Application Rule
Wash the raw iron, dry it completely over a low flame, and apply half a teaspoon of grapeseed oil. Now take a clean dry rag and attempt to wipe off all of it, as if applying the oil was a mistake.
The remaining microscopic sheen is the correct thickness. If you see pooling or visible liquid droplets, your layer is too thick and will turn into sticky gummy sludge in the oven. Bake inverted at 235 degrees Celsius for one hour, then let cool naturally.