Japanese Dark Soy Sauce (Koikuchi)

濃口醤油

Used in 7 recipes

Japanese Dark Soy Sauce (Koikuchi) ingredient photo

What is it?

Standard Japanese soy sauce — balanced salt and umami.

Culinary role

Seasoning, marinades, and dipping sauces across all categories.

Buying guide

Koikuchi shoyu (濃口醤油) is standard Japanese dark soy sauce — balanced salt and umami, not as heavy as Chinese dark soy and not as light as usukuchi (light soy). It seasons everything from dashi-based soups to gyudon simmering liquid and ramen tare on this site.

Buy Japanese-import Kikkoman or Yamasa in the glass bottle when possible; domestic US Kikkoman is brewed in Wisconsin and is good for daily use but flavor profile differs slightly from Japan-brewed bottles. Check for "naturally brewed" (本醸造) on premium labels.

Store at room temperature; soy sauce keeps months opened. Refrigeration slows flavor loss after opening in hot climates. Low-sodium versions exist — adjust recipe salt if substituting.

Budget pick: large jug of domestic Kikkoman.
Premium pick: yuuki (organic) or marudaizu (whole soybean) artisan shoyu from Japan. Never use "sweet soy sauce" or kecap manis — completely different products.