Anvils allow you to rename items, repair enchanted items, and even combine the enchantments from different items, at the cost of experience points. Crafting. You'll need 3 blocks of iron, plus 4 more iron bars, for a total of 31 iron bars.
Passivation is the treatment of the surface of stainless steels, often with acid solutions (or pastes), to remove contaminants and promote the formation of the passive film on a freshly created surface (e.g. through grinding, machining or mechanical damage).
It's deactivated yeast, frequently the strain used is Saccharomyces cerevisiae. Totally dead yeast. Usually it is cultured in something sweet for a few days, then heated to deactivate it. It adds a nutty, savory, almost meat-y depth of flavor to recipes. (The term is 'umami').