Barley koji starter culture | for Shoyu and Miso

Koji is the mold that can do anything: miso, soy sauce, shoyu, shio koji, amazake, black bean sauce, sake, doungjun, they all owe their amazing texture and flavor to the fungus Aspergillus oryzae. These spores can also be used, for example, to perform cool experiments with the fermentation of meat or even dairy.

The instructions for making koji-kin yourself (the moldy rice that forms the basis for most of the above-mentioned foods) can be found below.

This koji variant: Barley koji starter culture

Also big fan of the Noma Guide to Fermentation? They like to work with barley,  “Mugi” in Japanese. However, it is a rather sturdy grain, and normal koji spores have difficulty growing on it. This koji type however is well suited for barley koji.

To be used for all misos and soy sauces based on barley instead of rice. Has both a strong protease and moderate strong alpha amylase power, so it handles both proteins and carbohydrates well. Gluco-amylase is low to moderate. Strong glutaminase brings out the flavor. Well-known barley-miso varieties include Mugi Miso (12-18 months of ripening), mellow barley, Amakuchi Mugi Miso (fast, 1-2 months) and Nattoh Miso.

Content Barley koji starter culture

• Available in 2 sizes: 15gr. for 5 kg or 40 gr. for 200 kgs.
• Enough for a minimum of 5 kg of barley / grain / soybeans
• Grows best on barley
• Ingredient: rice flour *, Aspergillus oryzae fungus (koji)
• Storage instructions: shelf life at least 6 months in the refrigerator, spores last more than a year in the freezer.
• Origin: Japan
• Soy-free

(*) The small standard packages contain pure spores mixed with rice flour. The spores are so light that they’re very difficult to dose accurately in small amounts of rice. The quantity is small, they tend to stick to the bag, and the slightest breeze can send them flying across your kitchen.

The bulk-use bags contain pure spores only — they are not mixed with rice flour, so the spore concentration is much higher. With just 40 grams, you can make, for example, 200 kg of product or 360 liters of shoyu, depending on the type of koji.

Note: brown/greenish color

While most koji’s grow white, this koji tends to grow brown-greenish, even before the sporulation phase.  Use your nose (flowery, sweet) and tap the fermentation vessel to see if no (or few) spores have been formed when in doubt.

How to make koji-kin

Ingredients

• 300 g white rice, preferably not pre-cooked
• 0,5-1 g (about ½ tsp) koji-kin starter culture (check your packaging, different types of koji have different strenghts)

Preparation

1. Rinse the rice until the rinse water remains clear. Let it drain for 15 minutes.
2. Steam the rice for about 45 minutes. That works better than cooking it. Cooked rice quickly becomes wet and mushy when moldy, which prevents the fungus from doing its job properly. The rice should look glassy and feel soft and a little rubbery when you bite it.
3. Let cool to room temperature.
4. Mix the koji kin with the rice and let it ferment for 48 hours in a warm humid place 25 to 35 ˚C. Check regularly. Make sure to avoid condensation dripping onto the rice.
5. During this period, mix a few times with a clean fork. The fungus needs oxigen.
6. While most koji’s grow white, this koji tends to grow brown-greenish, even before the sporulation phase.  Use your nose (flowery, sweet) and tap the fermentation vessel to see if no (or few) spores have been formed when in doubt.

Buying barley koji starter culture?

Order your barley koji starter culture at startercultures.eu, the European webshop for all your fermentation needs. By Meneer Wateetons, renowned Dutch fermentation expert and author. Order on weekdays before  3 pm and we’ll ship the same day.  Questions on the usage of barley koji starter culture? Ask them in our chat, we’re here to help!

Online Miso making course

In 25+ bite-sized English spoken video lessons you will learn all about making Miso, without the need for special tools, in this online course by the founder of startercultures.eu. You will learn to make traditional, or ANY kind of Miso, save money, by never having to buy Miso again, and incite your culinary creativity!