Making real soy sauce is a journey of patience and skill. It cannot be rushed. Each step is done on purpose, guided by knowledge passed down through generations. This process is how we unlock the deep, complex flavors that make a truly great soy sauce. Let’s walk through this old method.
Step 1: Selecting the Foundation – The Purity of Raw Ingredients
Everything starts with the ingredients. You cannot make a great product from poor materials. That is why the first step is picking the best possible foundation. We choose only whole, non-GMO soybeans. Their rich oil and protein are needed for developing a smooth feel and deep smell after months of fermentation.
These soybeans are paired with high-quality roasted wheat. The wheat gives the starches that tiny organisms will turn into sugars. This adds a light sweetness and complex smell notes to the final sauce. It balances the savory depth from the soybeans. The only other ingredients are salt and pure water. This simple list is the mark of real soy sauce.
Step 3: The Moromi Mash – A Slow & Gradual Transformation
Once the Koji is ready, we mix it with a salt-water brine. This thick, fragrant mixture is called “moromi.” The moromi goes into large fermentation vats, where it will rest and age for at least six months, and often much longer.
During this long, slow change, a second and third stage of fermentation happens. Yeast and lactic acid bacteria, which were sleeping in the Koji, begin to work. The yeast eats the sugars to make alcohol and other smell compounds. The lactic acid bacteria add a slight tang that balances the flavor. Brewers are aware that such patient aging is the only way they can get a unique complexity developed over time. This is the heart of unveiling the craft of naturally fermented soy sauce.
Step 4: Pressing and Refining – The Art of Squeezing Liquid Gold
After the moromi has fully aged, it is time to extract the soy sauce. The mash is wrapped in layers of cloth and placed in a large press. Over several days, pressure is slowly applied. This squeezes the dark, fragrant liquid from the solids.
The liquid that comes from this first pressing is the highest quality. It is often called “first press” or “raw soy sauce.” It has the most vibrant flavor and richest smell. This raw sauce is then gently heated to stop fermentation and ensure it stays good. After a final filtering, it is ready to be bottled. This careful extraction is the final step in a long and beautiful process.
Some ask how we can keep this level of quality at a larger scale. Does “traditional” mean old-fashioned or uneven? For us, true craft is not primitive; it is about controlling the factors. It is about honoring the time-tested traditions with modern precision to make sure that each bottle has the same quality.
This philosophy is at the heart of our work. For instance, to achieve the perfect balance of real flavor and purity, we perfected our High-Salt Dilute Authenticity Brew™. This method respects the slow, multi-month fermentation process but it also uses precise controls over heat, moisture, and brine strength. This ensures that every batch develops the deep, complex flavor profile that is the hallmark of a true, naturally fermented soy sauce. It is this marriage of art and science that defines the modern master’s touch.