Whole-soybean shoyu vs ordinary shoyu: reading "defatted processed soybean" on the label

You have probably seen bottles in the shoyu (soy sauce) aisle with "marudaizu," whole soybean, printed large across the front. So what is in the shoyu that is not marudaizu? Surprisingly few people have stopped to ask.

The answer sits in the ingredient list on the back of the label: defatted processed soybean. It is the bean after the oil has been pressed out, the solid part alone.

Use the whole bean, or press the oil out first

Shoyu is built on soybeans, wheat and salt. How you treat that soybean splits the road in two.

Steam the bean whole and brew with it, and you have marudaizu. Take the oil out first and brew with what is left, and you have defatted processed soybean. After the war, using defatted processed soybean spread as a way to use ingredients and time efficiently, and today it accounts for much of what is on the market. It is a legitimate ingredient recognized under the JAS standard for shoyu, and its strength is that fermentation moves quickly and the savory notes come up clearly.

With marudaizu, the oil that stays in the ingredients breaks down into glycerin and fatty acids over the course of fermentation and aging. That process is said to be what leads to the fullness and the rounded, edgeless quality specific to whole-soybean shoyu.

This is a difference in design, not in rank

So neither one sits above the other. Do you want the savory notes drawn sharply, or do you want roundness and a lingering finish? It is a difference in design.

As a rule of thumb, the marudaizu difference is easiest to notice in uses where the taste of the shoyu itself is out front: chilled tofu, rice with raw egg, sashimi. In simmered or stir-fried dishes, where it overlaps with other seasonings, the gap softens.

Telling them apart is simple. If the ingredient list says only "soybean," it is marudaizu; if it says "defatted processed soybean," it is the other. This is a place where a difference of a few tens of yen changes the texture of the taste, so it is worth lining the two up and tasting them side by side at least once.

12 generations since 1789, a kioke brewery in Kawajima

Kawajima, Saitama Prefecture. In this town near Kawagoe, ringed by rice paddies, stands a shoyu brewery that has run for 12 generations since 1789. Fueki Shoyu, trading under the name "Kinbue."

Their flagship "Marudaizu Shoyu" is made from soybeans, wheat and sun-evaporated salt, nothing else. Whole soybeans rather than defatted processed soybean, brewed by tennen jozo (naturally brewed, no temperature control) for over 1 year inside large kioke (wooden barrels). The full taste the bean's oil brings is what this bottle is built on.

The main shop has "Kinbue Shoyu Park" attached, where you can walk through the brewery and see the kioke standing in rows. A bottle from a brewery that opened a place to see shoyu, learn about it and taste it is also a way into the food culture of Saitama.

"Shimousa Shoyu" from Katori in Chiba Prefecture (Chiba Shoyu, founded 1854) is another tennen jozo koikuchi (the standard dark shoyu), brewed in kioke from domestic whole soybeans, domestic wheat and salt alone. Its nitrogen content, the measure of savory compounds, runs 10% above the top-grade standard, and the yeast resident in the brewery grows an aroma found nowhere else.

How to choose, how to enjoy

• Read the ingredient list first: "soybean" or "defatted processed soybean." That is the starting point
• Try it as a pouring shoyu: chilled tofu or rice with raw egg shows the roundness of marudaizu best
• Use them for different jobs: in dishes that overlap with other seasonings, the bottle that fits your budget is plenty
• Refrigerate after opening: aroma is everything in whole-soybean shoyu. Pick a size you can finish in 1 to 2 months

Precisely because it is a drop you use every day, the habit of reading that one line in the ingredient list pays off. Next time you buy shoyu, turn the bottle over.

Frequently asked questions

What is the difference between whole-soybean shoyu and ordinary shoyu?

The state of the soybean used as the ingredient. Whole-soybean shoyu uses the bean entire, while most ordinary shoyu uses "defatted processed soybean," the bean after its oil has been pressed out. With whole soybeans the oil breaks down over the course of fermentation, which is said to give a fuller, rounder taste.

Is shoyu made with defatted processed soybean of lower quality?

It is not lower in quality. Defatted processed soybean ferments efficiently, with the advantage that the savory notes come up quickly. It is recognized as a legitimate ingredient under the JAS standard for shoyu, and it is closer to the truth to see it as a different approach to designing the taste. Treat it as a matter of preference.

How can you tell whether a shoyu is whole-soybean?

Look at the ingredient list on the back of the label. If it says only "soybean," it is whole-soybean; if it says "defatted processed soybean," it is the other. Many products also print "marudaizu" large on the front, so the reliable move is to check that wording against the ingredient list.