Name: Soy Sauce
Yield: 1 gallon

Soy Sauce

This recipe uses dried soybean and an added yeast culture specifically designed for making soy sauce.

The left over mash soybean mash can be used as miso. Miso paste can be added to other sauces or mayo, stir fries or used to flavor soup bases.

Ingredients

1200 g dry soybeans (the white or beige type)
1200 g wheat berries Soft wheat gives better flavor than hard wheat
7.5 g aspergillus orzyae starter meant for shoyu
825 g sea salt
3.8 l water

Steps

Step 1
Prepare the soybeans
1. Rinse the soybeans and cover them with water in a large glass jar or another suitable container. They will double in size when they absorb the water. Soak for 12 – 16 hours.
2. Step 2
3. Drain the soybeans and cook them in boiling water for 6 hours. A slow cooker is a good option in that case. When fully cooked, you should be able to easily crush the soybeans with your fingers.
Step 3

Prepare the wheat

Brown the wheat berries in a skillet for several minutes until they turn golden brown or broil them in the oven, spread over a baking sheet, stirring every couple of minutes to prevent burning, if you prefer.
Step 4
Grind the wheat coarsely using a food processor or grain mill. A course grind is fine.
Step 5

Preparing the koji

Mix ground wheat berries and soybeans in a large bowl. Allow to cool.
Step 6
Sprinkle a koji starter over the wheat and soy mixture. Stir well to thoroughly incorporate into the mixture.
Step 7
Spread over glass or stainless steel trays or bowls. Make furrows in the mixture every 2 inches.
Step 8
Place a thermometer in the koji and cover the trays with either a plastic wrap or a tight weave cloth to help keep the moisture inside. Incubate the trays at around 85ªF (32ºC).
Step 9
Check regularly to make sure the temperature remains at 80-95ºF (27-35ºC) range. If the temperature gets too high for too long (over 104ºF (40ºC), unwanted bacteria can grow in the koji and spoil it. Breaking up clumps by stirring as needed, respread and add the furrows back in, re-cover and continue incubating for 2 – 2.5 days. A white mold (may have some yellow or light yellow-green coloration.) Remove any dark green or black mold or that is sticky or shiny.
Step 10

Brine

In a large container (about 2 gallons), mix together 1 gallon water with 3.5 cups of sea salt. Stir until the salt has fully dissolved. Add the koji and cover with a tight fitting lid.
Step 11
Keep in a warm spot, stirring daily for 2 weeks. Store in a warm place (about 77ºF (25ºC)), stirring once a week for 6-12 months. It will darken and may separate.

Step 12

Straining

After fermentating, strain. The easiest way is probably to pour it into a cloth-lined strainer sitting in the opening of another food safe plastic bucket. Pour the mixture into the strainer. Fermentation will continue as long as the liquid is left in the original bucket with the wheat and soybean.

Obtaining a dark-colored soy sauce

Allow the sauce to ferment in the hot sun after bottling. This will cause a bit of residue to collect on the surface. Skim off and throw away or strain through cheesecloth again.