"What is shirodashi? How it differs from shiro shoyu and mentsuyu, and how to season without losing color"

No time to make dashi, but no wish to cloud the color of the dish either. That is the day you reach for shirodashi (白だし).

Shirodashi is also a seasoning whose name tells you little about what is inside. What separates it from shiro shoyu? Can mentsuyu stand in for it? Sort that out and where to use it comes into focus.

Shirodashi is "dashi plus a pale shoyu"

Shirodashi is a liquid seasoning that combines dashi - from katsuobushi, sababushi, kombu and the like - with a shoyu light in color. Most are concentrates, diluted with water or hot water before use.

The shoyu used here is either usukuchi (lighter in color, higher in salt) or shiro shoyu (pale amber shoyu). Both are pale, so the finished broth stays at amber and you can set the seasoning while keeping the whiteness of an ingredient or the green of a vegetable. It is easiest to think of it as dashi and shoyu, the foundations of Japanese cooking, gathered into a single bottle ahead of time.

The difference from shiro shoyu follows from the same structure. Shiro shoyu is itself an extremely pale shoyu, brewed mainly from wheat; its layer of savor comes from brewing rather than from dashi. Shirodashi adds dashi on top of that. So shiro shoyu, or usukuchi, is an ingredient, and shirodashi is a compound seasoning.

Mentsuyu is aiming at something else

Both are diluted liquid seasonings, but mentsuyu is after a different result.

Mentsuyu is built on koikuchi shoyu, sweetened with mirin or sugar. It is designed to cling to noodles and register, so it is dark and clearly sweet. Shirodashi is tuned the other way: to add savor and salt without adding color.

Use mentsuyu in chawanmushi, then, and the egg sinks toward brown. Use shirodashi for cold soba and both the color and the sweetness feel thin. Neither is better; the practical way to sort it is whether you want to add color or keep it.

From a katsuobushi dealer in Nihonbashi, 1699

Ninben started out in 1699 as a katsuobushi dealer in Nihonbashi (日本橋), in what was then Edo. Over more than three hundred years the house has stayed with katsuobushi and dashi.

Its "shirodashi" is a concentrate combining usukuchi shoyu with a blended dashi of katsuobushi, sababushi, soudabushi (dried frigate tuna) and kombu. Because three kinds of dried fish are layered in, a core of savor survives the dilution. On a day with no time to make dashi, this is the bottle that keeps the standard of a dish from slipping.

The "shirodashi" put together by Ando Jozo in Kakunodate (角館), Akita, has a character of its own. Its distinguishing move is a quiet addition of the local shottsuru, a fish sauce made here from iwana (岩魚, char), to a dashi of katsuo and kombu. That depth from the fish sauce means even a bottle cut with plain water tastes deep. It is carefully brewed and made with no additives.

How to use it, how to choose it

• Clear soups and chawanmushi: where shirodashi does its real work. The color of the egg and the broth stays as it is
• Dashimaki tamago: the seasoning settles in one move, and the yellow finishes bright
• Simmered dishes and takiawase: for when you want taro or turnip to come out of the pot still white
• Lightly pickled and dressed vegetables: a small amount in place of salt and shoyu. The color of the vegetables does not sink
• When choosing, read the ingredients: which dried fish and which kombu, and whether the shoyu is usukuchi or shiro shoyu, set the direction of the flavor

Start with chawanmushi, or a rolled omelette. The difference in color you can see before you taste anything.

Frequently asked questions

What is shirodashi?

It is a liquid seasoning that combines dashi, from katsuobushi (dried bonito) and kombu among others, with a pale-colored shoyu - either usukuchi or shiro shoyu. Most bottles are meant to be diluted, and the great advantage is that you can set both savor and salt without clouding the color of what you are cooking. It goes into clear soups, chawanmushi and simmered dishes.

What is the difference between shirodashi and shiro shoyu?

Shiro shoyu is a seasoning in itself; shirodashi is a compound seasoning made by adding dashi to it. Shiro shoyu is an extremely pale shoyu brewed mainly from wheat, and on its own it carries none of the savor of dashi. The difference with shirodashi is that the work of making the dashi has already been done for you.

How do I decide between shirodashi and mentsuyu?

Shirodashi for dishes where you want to keep the color, mentsuyu for dishes where you want to add it. Mentsuyu is built on koikuchi shoyu with sweetness added, so the broth finishes dark. For chawanmushi, dashimaki tamago or lightly pickled vegetables - anything where the whiteness or the colors of the ingredients matter - shirodashi gets you the look you were aiming for.