Kikkoman Australia

NATURALLY BREWED VS NON BREWED

THE NATURAL BREWING PROCESS

Brewing is accomplished in three distinct steps: koji making, brine fermentation and refining.

1. Koji making (Culturing Process)

The process begins by carefully selecting soybeans and wheat under precisely controlled conditions. Next, a seed mould, Koji aspergillus is introduced, and the mixture is allowed to mature for three days in large perforated vats through which air is circulated.

2. Brine Fermentation (Moromi)

The resulting culture, or koji, is then transferred to special fermentation tanks and mixed with salt water to produce a mash called “moromi” The next, and perhaps, most critical step is allowing the moromi to ferment for several months using lactic acid, bacteria and yeasts. During this time the soybeans and wheat transform into semi-liquid, reddish brown, “mature mash”. It is this aging process that creates the many distinct flavour and fragrance components that build the soy sauce flavour profile.

3. Refining

Following the months of moromi fermentation, the raw soy sauce is separated from the cake by pressing it through layers of filtration cloth. The liquid that emerges from this filtration is then refined, pasteurised and packaged as finished soy sauce.

THE NON BREWING PROCESS
The procedure for producing nonbrewed soy sauce is entirely different.

First, soybeans are boiled with hydrochloric acid for 15 to 20 hours. After the soybeans yield their maximum amount of amino acids, the mixture is cooled to stop the hydrolytic reaction. The amino acid liquid is then neutralised with alkali (sodium hydroxide), pressed through filter, mixed with active carbon and finally, purified through filtration.

Caramel colour, sugar (for sweetness) and salt are typical added to this hydrolysed vegetable protein mixture.

To improve chemically hydrolysed soy sauce, a semi chemical procedure is sometimes used. Here, the beans are hydrolysed with lower concentration of hydrochloric acid. The resulting hydrolysate is then fermented with yeast in the presence of wheat koji.

While this procedure is said to improve the flavour and aroma, the resulting product still is considered a chemical soy sauce with undesirable compounds.