How to Make Kome-Koji (malt-rice)

Rice serves two purposes in sake making. The first purpose is to provide a medium for the Koji-Kin to develop and create the enzyme rich Kome-Koji (malt rice) necessary to convert the rice into simpler sugars. The other purpose is as a food source for the yeast that is added to convert the sugars into alcohol; however, this is not possible without the creation of the Kome-Koji.

When making Kome-Koji, a portion of rice is steamed and inoculated with the Koji-Kin seeds, or mold spores, and incubated for about 40 hours. The rice will become covered with white soft fibers, have an aroma slightly similar to roasted chestnuts and should be firm and slightly sweet. The Malt-rice (kome-koji) is now able to convert regular steamed rice to simple brewing sugars.

Ingredients:

1 pound of short grain rice (unprocessed ready to steam), about 2 cups
1/2 teaspoon of Koji-Kin mold seeds
1 teaspoon All Purpose Flour (optional)

Equipment:

Large bowl to contain rice plus 3 – 4 quarts of water
Colander, sieve or bamboo steamer
Nylon draining bag to contain rice in steamer
One large pot with lid to contain sieve/colander/bamboo steamer
Cotton cloth to absorb water condensation from the pot lid

Procedure:

Wash the rice several times with cool water until the water runs nearly clear.
Soak the rice for two hours.
Place the rice in a colander or sieve for 1 hour to drain away any excess water.
Steam cook the rice.
Cool the cooked rice to 86° F.
Combine ½ teaspoon of Koji-Kin with 1 teaspoon of flour. The flour helps distribute the mold into the steamed rice. The spore packet contents are unaffected by repeated openings.
Put the rice into a non-reactive container and gently mix in the Koji-Kin and flour. Make sure you get an even distribution. A fine metal sieve or tea strainer is useful.
Cover the container with moistened cheese cloth or cotton towel to prevent drying. Place the covered container in a place that will maintain the 86 °F temperature for 2 days. This can be done by placing an electric heating pad (set on low) inside an inexpensive Styrofoam cooler or by using plastic bottles filled with hot water inside a cooler. The hot water will have to be exchanged periodically, such as every time you stir the grains.
Keep the inoculated rice at 86° F and stir the grains every 10 hours to distribute the mold evenly. Notice the rice becomes white after 15 hours accompanied by an unusual, but not objectionable, aroma. It has been described as similar to cheese or roasted chestnuts.
Maintain the rice at 86° F for a total of 40 hours. Your rice will become covered with white soft fibers and should be firm and slightly sweet. The Malt-rice (kome-koji) is now ready to convert regular steamed cooked rice to brewing sugars.
It is possible for the beginner to grow a strange exotic mould or bacteria in error and if used to make a brew, could be toxic and unpleasant to drink. Please use your common sense, if something is unpleasant smelling or tasting, don't consume it!

Tips to help you recognize and grow Kome-Koji.

Kome-Koji is always white or slightly tan colored.
The smell of Kome-Koji is a cheesy strong smell (not a moldy smell), perhaps not a lovely smell but not an unpleasant "off" smell.
Small white fibers are seen to be growing from the rice in the later stages. If you grow fibers that are not white in color, do not use this batch as you are growing another mold as well as Koji.
To grow a mono culture of only Koji, distribute your Koji-Kin (seeds) very evenly and liberally using a fine metal sieve or tea strainer, making sure you thoroughly mix the rice and seeds.

Stainless Kettle 20 qt. $48.95
Stainless Kettle 30 qt. $88.95

Spoon Stainless Perforated $2.95
Spoon Stainless Solid $2.95

reusable nylon 18 x 32 inch

Heavy duty coarse weave nylon mesh bag fits a six gallon pail. It is for use with grape and fruit presses and will also hold a large volume of cheese curd for draining.

reusable nylon 10 x 23 inch

Re-usable coarse weave nylon straining bag

Brew Belt $22.95
This belt is designed to wrap around most primary and secondary fermenters. It heats at a constant 75 - 80° F. It works for wine, beer and cheese making.

Cheese Cloth Fine 2 yd. $5.95
Cheese Cloth Fine 60 yd. $159.00
Used for draining soft cheeses, butter and yogurt. Easily cleaned and reused.

Sake Koji-Kin Kit $11.95
Rice that has the correct mold growing on it will act like malt and convert further rice starch to sugar. This is the principal of Sake making. This special rice is called Kome-Koji. The mold seeds are called Koji- Kin and create the enzyme rich Kome-Koji to create complex and interesting flavors similar to mold used in cheese making.

Sake Rice 5 lb. $9.95
Select California premium short grain rice. Kapika is a rice milling process that allows rice grains to polish each other without the use of water or brushes as in traditionally milled rice. The Kapika process creates highly polished rice, which increases water absorption and promotes excellent taste and texture. The more milling rice undergoes the more complex the flavor of your sake will be.