steel pans improve their easily corroded
surface by building up an artificial protective
layer. They “season” them by coating them
with cooking oil and heating them for several
hours. The oil penetrates into the pores and
fissures of the metal, sealing it from the
attack of air and water. And the combination
of heat, metal, and air oxidizes the fatty acid
chains and encourages them to bond to each
other (“polymerize”) to form a dense, hard,
dry layer (just as linseed and other “drying
oils” doon wood and on paintings). Highly
unsaturated oils — soy oil, corn oil — are
especially prone to oxidation and
polymerizing. To avoid removing the
protective oil layer, cooks carefully clean
seasoned cast iron pans with mild soaps and a
dissolving abrasive like salt, rather then with
detergents and scouring pads.
Stainless Steel