/ck/ - Food & Cooking

>>12664677
I don't know what to tell you but this is literally (literally) what is happening, as explained to a layman.

Metals from which you could make a pan (stainless steel, carbon steel, cast iron, aluminum, copper, etc.) can be polished smooth during manufacture, but no polish—even one taken to a mirror—can completely eliminate defects in the surface of the metal. This is because metal is crystalline.
When liquid metal is allowed to cool it tends to crystalize in whichever way the metal prefers (this is evocatively called a substance’s crystal habit). These crystals start out as islands of ordered metal atoms in the cooling liquid steel or copper or iron. The crystals grow larger and larger as the liquid cools and eventually meet each other. The solidity of a piece of metal as we experience it is a result of these crystals locking together when the last of the liquid metal is crystallized. The borders between these crystals, in metallurgy called the grain boundary, determines many of the bulk metal’s properties. Here are the very small grain boundaries between crystals of steel.