Simmered Black Soybeans and Grapes

When sourcing dried black soybeans, sort out ones that are cracked or undersized to some degree and even out the sizes. Beans with split or dented skins are an obvious problem, but occasionally you also get beans that were simply over-dried from the start. Those aren't good either. So we make a point of sourcing good-quality beans to begin with. Because these are dried beans, if the skin around them takes a hard knock or gets scratched, they crack just like glass, so when spreading the beans out on a tray to sort them, we lay down something like a cloth underneath first. We always handle them carefully and never roughly. If a bean cracks, the starch inside dissolves and leaks out, which causes spoilage and shortens how long it keeps. Black soybeans made at home are wrinkled quite deeply on purpose, so the starch doesn't tend to leak out from inside, but the ones we cooks make are finished so the skin and the flesh reach the same firmness, which inevitably makes them more prone to cracking.

Put the beans in a pot — what's added differs from shop to shop, but at ours we use just a little baking soda, pour boiling water over them, seal the pot, leave it until morning, and then put it straight on the heat. We do this over the course of several days until the skin and the flesh of the beans reach exactly the same firmness, and once they've fully rehydrated, we rinse them thoroughly in water and sort out any beans that have split further in the process. That's why a single black soybean can, depending on the case, end up costing several hundred yen.

By the way, the inferior beans set aside at the start are rehydrated along with the rest, and together with any that crack along the way, they're passed through a fine sieve and used as is, or combined with things like mashed sweet potato to make a cloth-wrung bundle shape, or used in appetizers and the like.