Japan — tonyu production documented since at least 8th century with Buddhist tofu introduction
Tonyu (豆乳, soy milk) is Japan's traditional soy milk — the liquid extracted from soaked, ground, and cooked soybeans before tofu coagulation. Japanese tonyu is categorically different from Western soy milk: unsweetened, thicker, with more pronounced beany flavor appreciated as a healthy breakfast drink. Multiple grades: regular tonyu (50g soybeans per 1L — thinner), and adjusted tonyu (80g+ per 1L — cream-like). Applications in Japanese cooking: tonyu hot pot (tonyu nabe), tonyu ramen broth, tonyu soup base for winter warming dishes, and drinking straight from the street vendor machine (a Tokyo market tradition).
Clean, beany, lightly grassy — unsweetened milk of the soybean; richer when concentrated
{"Tonyu production: soak soybeans overnight, blend with water, strain through cloth, boil","Yuba (tofu skin) formation: skin forms on surface during heating — a byproduct and luxury product","Concentration affects flavor: higher soybean ratio = richer, creamier, more intense","Boiling required: raw soybean liquid contains enzyme inhibitors — must be cooked","Tofu production: add nigari (magnesium chloride) to hot tonyu to coagulate into tofu","Refrigerate immediately: tonyu spoils quickly; consume within 3 days"}
{"Yuba harvest: heat tonyu to 80-85°C, wait 5 minutes — skin forms, lift with chopstick","Tonyu ramen: replace one-third of tonkotsu broth with tonyu — creamy, white broth variation","Tonyu nabe: simple winter hot pot using tonyu as broth — add dashi to dilute","Okara (soybean pulp after straining): use in karaage coating, simmered dishes, or baked goods","Tonyu dressing: blend with sesame paste + rice vinegar + mirin for creamy salad dressing"}
{"Not boiling sufficiently — raw tonyu enzyme inhibitors cause digestive issues","Straining too fine — some residue (okara) in tonyu adds body to cooking applications","Sweetening for savory applications — commercial sweetened tonyu inappropriate for cooking"}
Japanese Soy Product Culture — Tofu Making documentation; Traditional Soy Foods Japan