All starters are imported from 'Hishiroku', one of the prominent Koji makers in Japan with 300 years history behind them supporting the traditional Japanese condiments industries and sake makers.
Koji spores are selectively bred and blended by Hishiroku for the best performance for the chosen purposes. For example, some spores performs better at protease production that breaks down protein into amino-acids, therefore, they are good at fermenting protein rich food, such as soybeans and meat, turning them into umami bomb. The koji spores chosen for this purpose are the best performers at the low temperate range which encourages protease production.
We recommend to use only the Koji starters from the renowned Japanese Koji makers every time you make Koji, instead of trying to reproduce the spores which could invite contamination with other microorganisms.
Please note that we are suspending the shipment of Koji starters to the EU due to tightened regulation until further notice.
Storage and Handling of Koji Starter
· Store in the fridge, preferably in the chiller drawer.
· Once opened, keep it in an air-tight container or Ziploc bag, preferably with a desiccant, to avoid the moisture and the cross contamination. Store in the chiller drawer in the fridge.
· 20g of koji starter makes up to 15kg of rice koji. For small volume of koji making, use 2-3 times more starter to ensure the best result. For example:
o 20g koji starter for 15kg rice
o 4-5g koji starter for 1.5kg rice
· The koji starter maker HISHIROKU recommends that the koji starter should be used up in 6 months. Nonetheless, it does not mean it is unusable beyond this date. Koji germination rate lowers with time, so you need to use more koji starter to compensate the reduced performance. Although the germination cannot be guaranteed, it generally lasts for a lot longer than 6 months.
Koji (Aspergillus Oryzae) is a type of mould, native to Japan. Unlike yeast which grows fast by budding, Koji grows much slower by germination.
Slow growing means that it is more susceptible to cross contamination during the propagation.
The koji propagation requires the specialist skills developed by the Koji makers through generations. Each koji starters are selectively bred and blended for the purpose, therefore, any attempt to propagate at home for continuous usage may jeopardise the intended function of the koji spores, and even risk safety.
How to store the rice koji
As soon as the rice koji is made, you need to dry them for 1-2 days in a cool, clean place out of the direct sun light and wind to stop further fermentation until you are ready to use them. After drying, store them in an air-tight clean container or vacuumed bag as follows:
· Up to 1-2 days - dark cool storage at 15°C or lower
· 2-21 days - in the fridge
· Up to 3 months - in the freezer
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