If the belt on your R&D budget hasn’t tightened already, it’s bound to start pinching soon. While formulators always aim to trim the fat, now more than ever they require the product-development equivalent of the “little black dress,” an ingredient that’s functional, economical and versatile.
That little black dress may already be hanging in your test-kitchen closet, but it’s more amber than black, and it’s more liquid than lace. It’s soy sauce, which in any of its process-friendly forms enhances flavor, balances flavor profiles, and coexists peacefully in clean-label and even reduced-sodium formulations.
Great taste in the making
The natural brewing process for soy sauce hasn’t changed much in the past 2,500 years. In its specifics, however, modern soy sauce fermentation is a tightly controlled practice.
“At Kikkoman, it starts with the inoculation of a blend of American-grown soybeans and wheat with the seed mold Koji aspergillus,” says Mike Evans, vice president, sales and marketing, Kikkoman Sales USA, Inc., San Francisco. After several days of maturation, the resulting culture, called a koji, is mixed with a salt brine to form a mash known as a moromi. The moromi ferments for several months, during which osmophilic lactic acid bacteria and yeasts turn the wheat and soybeans into a reddish-brown, semiliquid “mature mash.” Then a sequence of pressing, filtering, pasteurization and refining hones this mash into finished soy sauce.
With the moromi tied up for months in fermentation, natural brewing will never qualify as a quick-turnaround process. But during that 6-month maturation, soy sauce develops the complex fingerprint that accounts for its character and functionality.
“The defining quality of a stellar soy sauce lies in its flavor balance,” Evans says. “And that flavor balance is a direct result of fermentation.”
The elements of enjoyment
The savory sweetness and complex richness of brewed soy sauce results from fermentation and a combination of ingredients. Among these is salt, which tops out at between 12% and 18% in a naturally brewed product. This salt comes from the brine, not from the fermentation, but it’s essential to the process, as it creates an optimal osmotic environment for the bacteria and yeasts.
Those yeasts feed on at least a dozen different sugars liberated from wheat starch by moromi enzymes, generating ethanol and other aromatic alcohols in the process. Some of those alcohols react with other portions of the sugars to produce more than 10 different organic acids, including lactic and succinic. A finished soy sauce will have a pH of about 4.8, and 1.0% lactic acid, which helps temper the sauce’s saltiness and introduces a pleasing tang. Organic acids interact with the ethanol to produce the aromatic esters that give a fine soy sauce its bouquet.