Not terribly much here, and I’d never call a $150 folding proofer an “essential.” I just like it, is all, both for rising and proofing (proofing being the second rise just before baking). For rising you really don’t need anything more than a large bowl or pot and a cloth to cover. However proofing containers like those on the left there are quite helpful. The hash marks on the sides let you gauge how fast your dough is rising and to what volume. They have many other uses in the kitchen as well, like measuring large quantities of fruit or brining chickens. Trust me, you need some.