Seasoning cast iron cookware is a practice shrouded in mystic. A general consensus is unable to rise from the rabble of misconception and anecdotal evidence. Some methods are handed down through the generations others picked up amongst dinner time conversation. Everyone is an expert. But what is the best oil to season cast iron? This is the question I asked, and began my research.
Polymerized reactions, a basic polymerization reaction involves the cross-linking of carbon-carbon double bonds within fatty acids using oxygen and possibly other things, including iron, as a catalysts. This reaction is what causes the glossy coat which your food glides across. When an unsaturated fat is heated to high temperatures, it is broken down and oxidized, after which it polymerizes. This reaction occurs when the oil is heated past its smoke point. Technically, the reaction will occur to an extent below the smoke point, but we must not get hung up on semantics. We are here to determine the best oil to season cast iron.
The best oil to season cast iron is going to be an unsaturated fat. Flaxseed Oil, was made famous as an alternative to vegetable oil by a blogger named Sheryl. She claims to have done vigorous research and arrived at this conclusion via science. She has started the biggest debate in cast iron oil history. Flaxseed oil is the food grade alternative to linseed oil. The logic is that being a drying oil, flaxseed which produce the hardest polymer. Drying oils are characterized by high levels of polyunsaturated fatty acids, especially the omega-3 fatty acid ALA. Sheryl attribute the presence of free radicals to the oils ability to enable polymerization.
When the internet hears free radicals people are going to lose their minds. It is inevitable, they are one of the buzz words associated with cancer. Is this prejudice fair? This has divided people into two camps. A free radical is an uncharged molecule (typically highly reactive and short-lived) having an unpaired valence electron. Do all the free radicals find electrons to bond with and makes a nice cancer free non-stick film? Or do they wait around to poison our food who is to say?
My outlook on this was that, everything claims to give you cancer now a days and if it was really that dangerous we would know for certain. So I seasoned a pan with Flaxseed oil. I used the good stuff, all organic food grade, no additives of any kind. I rubbed a thin layer of the oil onto my skillet turned the oven to its highest setting and left it for an hour. I let it cool down in the oven as per Sheryl’s instruction and took it out two hours later.
The results spoke for themselves, the skillet was the best it has ever been. I have always used vegetable oil and found the flaxseed oil to yield a much better result. This is in my opinion the best oil to season cast iron cookware.