• Common Product Name: Kiippon Kuromame Shoyu（生一本 黒豆醤油）— pure black soybean soy sauce See our guide to Japanese soy sauce types.
• Volume: 200ml (6.8 fl oz)
• Ingredients: Black soybeans (Japan), wheat (Japan), salt — no additives
• Allergens: Contains soy and wheat. No preservatives, no coloring.
• Best Before: Approx. 24 months from production date (unopened)
• Storage: Cool, dark place; refrigerate after opening. See our full storage guide.
• Origin: Yuasa, Wakayama
• Producer: Yuasa Soy Sauce Co., Ltd.（湯浅醤油有限会社）

Yuasa, a small coastal town in Wakayama, is recognized as the birthplace of Japanese soy sauce. In the 13th century a monk returning from China introduced a fermented soybean paste called kinzanji miso; local brewers, noticing the savory liquid that drained from the aging paste, began collecting and refining it — and shoyu was born. The tradition never left. Yuasa’s brewing method now holds GI protected status, and Yuasa Soy Sauce still works in the town’s original way: whole soybeans, wheat, salt, cedar barrels, and time. Kiippon Kuromame — made from Tanba black soybeans prized since the Nara period for their size and sweetness — is the brewery’s statement of what Yuasa soy sauce can be at its finest.

Black soybeans make a soy sauce noticeably different from conventional yellow-soybean shoyu: a deeper, reddish-brown color, and an aroma that is rounder and slightly sweeter beneath the familiar savory note, with a woody warmth from the barrel. On the palate the umami is full and long, without a sharp salt edge; the finish is clean, gently sweet, and genuinely satisfying — the kind of soy sauce that quietly changes what you think soy sauce can taste like.

Start with a single drop over sashimi, sushi, or cold tofu, where its rounded sweetness needs nothing but itself. Brush it onto grilled fish, chicken, or yaki onigiri in the last moments of cooking for a glossy, caramelized finish, or add a splash to simmered dishes for a depth ordinary soy sauce cannot reach. For the home cook drawn to the fermentation and gut-health movement, this is the real thing — live, additive-free, slowly aged in wood. And it makes a teriyaki from scratch — with a little mirin and sake — that tastes nothing like the bottled kind.