Ume Syrup (梅シロップ, Ume Shiroppu)

Green ume come to market for a short, bossy season, late May into June, still hard, sour, and bright under the skin. This is their 旬 (shun), the moment they're at their prime, and it doesn't wait politely while we look for a prettier weekend. Buy them firm, green, and unbruised. If they're soft or browned, change the plan. Nothing hidden.

Ume syrup looks like a trick because no cooking begins it. Equal weights of fruit and kōri-zatō, Japanese rock sugar, sit together in a clean jar while the sugar slowly draws the sharp juice out of the ume. That slow melting matters. Rock sugar doesn't flood the jar at once; it coaxes the fruit, and the syrup comes out clear, fragrant, and tart enough to wake up a glass of cold soda.

The one detail that decides it is dryness. Wash the fruit, yes, but then dry it completely and make the jar clean enough to make you feel slightly foolish. Water sitting in the stem end is where mold starts, and mold is not a philosophical problem. It's a reason to begin again. Keep the jar cool and dark, turn it every day, and in three weeks you'll have honmono in a bottle: Japanese summer, sour and sweet, made without fuss.