Greg Blonder – Cast Iron Seasoning:
Cast iron pots are heavy. They can rust. The dark black seasoning will not stand up to hours of simmering if the liquid is acidic, like tomato sauce or sauerkraut. And once the seasoning layer is broached, excess iron can leak out of the pot into your food, risking iron overload disease. Thermal conductivity is eight times lower than copper, which is why cast iron fry pans are notorious for hot spots. The surface is mildly non-stick, but requires a bit of oil or fat to reach its full potential. Cast iron can be cleaned, but not aggressively. And I never use my cast iron pots to cook caramel or make crepes or to scrape off a tasty “fond”.
Thus starts an in-depth analysis and recommended method of cast iron seasoning.
As for myself, I don’t bother with fancy oils and use plain old canola/rapeseed oil. It has worked well for the past several years.
A few months ago, I reseasoned my Lodge 10.25″ cast iron pan for the first time (and seasoned a new 12″ seasoned steel pan) in order to remove any potential allergens from our pre-allergen-free cooking days. We had gone on for over a year without using these pans due to our concern with lingering allergens in the pan, which was pretty painful. I didn’t do the piranha etching, but built a large fire in our Weber grill and placed the pan directly on top of the fire for about an hour. The vents were wide open on the grill, and the high heat burned off all of the old seasoning. After three sessions of wiping on a thin layer of canola oil and putting the pans in a 450°F oven for an hour, a suitable seasoning was achieved.
While over time the seasonings have taken a beating, I’m not going to bother with reseasoning since it is still reasonably non-stick, and anything that does stick will scrape off easily after burning it off and scraping with a spatula.