The Magic of Soya Sauce

A Collection of Escarpment Labs Shoyu Experiments Through the Years 

It's no secret that we love food fermentation at Escarpment Labs, and that includes soya sauce. In fact, we love it so much that we started making it ourselves, with around 100L collectively made over the last 3 years. This includes smoked buckwheat, spent grain, garlic cayenne and traditional varieties. Most of these sauces have been featured in our staff meals and some even in our famous hot sauces.

With everything we've learned (and tasted!), let's check out some of our findings so you can try your hand at something new in your kitchen this fall!

What is Shoyu?

Shoyu is Japanese soya sauce, traditionally made of soybeans and roasted wheat. Koji starter (Asperilligus Oryzae) is grown on these two grains, at a 1 to 1 ratio. After the initial inoculation and growth, it is mixed with water and salt. The salt ratio depends on how long you plan on fermenting the sauce before use — the lower the salt ratio, the faster the sauce will be ready. However, some of the deeper flavours can only be achieved through a lengthy fermentation, sometimes upwards of 2 years! 

At Escarpment, we have explored a variety of fun shoyu ferments, from traditional soybean and wheat to buckwheat, smoked wheat, and garlic, to shoyu made exclusively with spent grain. All present unique and inspired flavours that brighten up a dish, are packed full of umami, and tell an interesting story of flavour and in some cases, sustainability.

We tend to make our soya sauce (and other amino sauces)  a little different from the traditional way. Instead of growing the koji starter on soybeans and wheat, we use our freeze dried Koji Rice and add it to whatever substrate we like. Using this way means that you don’t need to buy a lot of the incubation equipment that is needed when growing koji from a starter. 

Note: Be careful when looking at soya sauce recipes. The term “koji” refers to both the start inoculant and the grown and finished ingredient. The koji we sell is the finished ingredient and is ready to use, but will require hydration in most cases for shoyu.

Shoyu Sensory Testing

In April of 2022, we ran a soya sauce sensory experiment to see how our soya sauce stacks up to the commercial brands. We only used commercial brands that contained “Aspergillus Oryzae”(meaning it is made with koji), since you will find soya sauce that are made with active cultures. To prevent any biases we ran the test blind.

Data provided and collected by our Data Scientist & Production Specialist, Hana Knill

Generally we found that our staff liked the commercial products better than the house-made counterparts, but our shoyu still performing well overall. This is not surprising since the commercial soya sauce has such a recognizable and mild flavour. Our sauces were definitely more funky, which can be surprising when tasted “straight up”.  However, we have found that this flavour adds more complexity when added to other sauces like BBQ sauce, tomato sauce or wherever you want the extra dose of umami. 

Making Shoyu at home with Escarpment Labs Koji Rice

While not made with traditional methods, you can make delicious shoyu at home with our freeze dried, ready-to-use Koji. This type of shoyu is best used in recipes to add umami, as we mentioned above. For example; garlic shoyu makes an excellent addition to your pizza sauce for an extra little zing.

Seeing as this recipe takes around 3 months to complete, I suggest that you make the most of your time & start out by making a bigger batch by using two of our Koji pouches so that you have enough for multiple recipes, and go from there. 

Recipe below is provided by Richard Preiss.
  1. Rehydrate Koji with 450-500 mL (per 1 Koji packet) of lukewarm water, make sure you add a little water at a time in order to not flood the koji. 
  2.  Mix 1 part rehydrates rice koji with 3 parts substrate
    • Substrates could be; cooked soybean beans, spent grain, or wheat to list a few. Have fun coming up with different blends!  
  3. Get a sanitised jar large enough to hold everything and tare it on a scale. 
  4. Add the koji and substrate. Top up with water until it is liquid/stirrable. 
  5. Measure the total weight of koji, substrate, and water. Mix in 10% of the weight in salt
    • eg: if the total weight is 1000g, add 100g of salt
  6. Stir weekly until desired flavour profile, typically 2-3 months for a light/young shoyu.
  7. Strain with cheesecloth and proceed to bottle. Keep in fridge. Dried solids can also be used in other recipes.

It is important to note that this recipe is considered a “short-term” ferment. Therefore the flavours will be lighter. A general rule of thumb when adjusting the recipe for long term is;

Short term: less salt, more koji
Long term: more salt, less koji

Examples from the Escarpment Labs Kitchen

What kind of things can you add a little umami flavour to? The possibilities are endless. If you're looking for some inspiration, check out some of these staff meals that we've made over the last couple years!

  1. Sushi with a basic shoyu (our perfect accompaniment for the sensory experiment!)
  2. Momofuku-inspired Pork Belly Shittake Mushroom Bao (Pork belly marinated in shoyu, garlic miso, and vinegars)
  3. Tacos with pork marinated in a buckwheat and garlic shoyu marinade
  4. Swedish Meatballs with a mushroom gravy with spent grain shoyu
  5. Shoyu made with spent grain (one of our efforts to use up-cycled ingredients from our R&D brewing efforts)
  6. Sausage pizza with a Koji Flour and Sahti yeast pizza crust, tomato sauce with smoked wheat and shoyu solids, house made spicy italian pork sausage with cayenne shoyu solids, in addition to lacto fermented banana peppers & smoked mozzarella.

Have any questions about koji, shoyu, or any of our other food ferments products? Feel free to reach out in the comments below! 

Special thanks to fellow past & present Escarpment Labs staff who have contributed the recipe ideas for shoyu, data, and R&D efforts towards making our Koji Rice, particularly: Jonah Greenbaum-Shinder, Hana Knill, & Richard Preiss.

Our koji is grown in an ideal environment created by a perfect balance of heat and humidity, before being harvested, freeze-dried, and sealed in our ready-to-use pouches. This versatile, single-use product can be used to make many different fermented foods, allowing for new techniques and flavour experiences.

Get your koji on!

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