I have meant to post a little something about anazake for some time but I keep putting it off. Now that I have gotten a question about how to make it I can see that it is overdue and I should get my act together. Amazake is a rice and koji mixture that is most thought of as a drink but has other uses as well.
OK, so to make amazake you need koji and rice. You can make koji with the method discussed in the earlier post, “Making Koji for Sake.” In this case you will need to start with koji-kin. If you prefer you can skip making your own and just buy the koji. I have both koji and koji-kin in the store.
Once you have the ingredients, koji and rice, cook 3 cups of rice just as you would to eat the rice. When cooked, thoroughly mix 1 cup koji with the now 3 cups of cooked rice. Leave this in a warm area (75F-85F is good but could be as high as 140F) for between 6 hours and 12 hours. You should stir this every couple of hours; each time tasting it. It should get sweeter and sweeter until it stabilizes. When it stops getting sweeter it is done. At this point it should be quite mush like. Put it in a sauce pan and boil it for 5 minutes but be careful not to scorch it. This denatures the enzymes and stops the transformation.
If you let it go longer before boiling the amazake, it will start to pick up a sour flavor. The sourness will continue to increase until the amazake is no longer desirable. So be sure to continue to taste it to meet your liking. Amazake will keep for 1-2 weeks in the refrigerator.
However, what we have just created is not the amazake drink but rather an amazake base that can be used to make the drink, or as a sweetener that can be used to replace sugar. As a sweetener, use a quarter cup amazake base per tablespoon of sweetener and reduce the liquids by 3 tablespoons.
For a hot drink use 1 part of this base with 2 parts water, heat and mix well. You can season this with ginger, cinnamon or whatever appeals to you. For cold drink use the same proportions but you can choose to change out the water for juice if you like. Blend for a smooth drink.
That is about all there is to it; surprisingly simple and, at least for me, incredibly amazing. I started making amazake as a way to “test” the koji I was making. It is really amazing how the koji can transform the rice. The more diastatic power the koji has the faster the conversion.
Geek alert: Diastatic power is measured in degrees Lintner which the JECFA defines as:
A malt has a diastatic power of 100 °L if 0.1cc of a clear 5% infusion of the malt, acting on 100cc of a 2% starch solution at 20°C for one hour produces sufficient reducing sugars to reduce completely 5cc of Fehling’s solution.
Diastatic power is most commonly used to discuss the ability of a malted grain to self-convert, that is, the level to which the enzymes in the malt can convert the starches in the malt into sugar. This requires a diastatic power of around 35 degrees Lintner. The most powerful malts, diastatically speaking are above 150 degrees Lintner. Koji, while often using the terms malted rice or rice malt is really very different from what is discussed in malted grains. Sorry for the confusing language here but the reuse of the term malt gets in the way of a clear discussion. The malting process for grains is one of causing the grain seed to begin to sprout, and then halting the process. The seeds create enzymes to transform itself during this process. Rice, also being a grain can go through the same process but once the rice has been milled it can no longer be “malted” or have the sprouting process begun. So, rice malt after milling, is referring to rice with mold growing on it (i.e., koji) that will supply the needed enzymes.
The diastatic power of koji must be quite high in order to, not only self-convert, but also to convert the rest of the rice in the mash which is generally 4 – 5 times the amount of koji. If I can find a reasonably easy way to measure the diastatic power of koji I will post the method, but for now I don’t have one.