While shopping I happened to come across a package of yeast balls for making Chinese rice wine, and bought it on impulse. The week before, I had joined a bunch of friends in brewing beer, and was in the mood for more alcoholic adventures. So I decided to give it a try, with Clara F, who was also a fellow beer-brewer, and some guidance from recipes on the web (here, here, here, and here). It turned out to be remarkably straightforward, and doesn’t require anything special beyond the yeast and glutinous rice. Here is our recipe and some pictures of how it went!
You will need:
- Glutinous rice
- Chinese rice wine yeast balls 酒饼 or 酒曲 (see picture)
- Glass jar (clean and grease-free)
- Sieve, funnel, bottles, and a clean cloth for straining
- Soak rice overnight in a cooking pot. We used about 300 g, or two to three cups.
- Rinse rice a few times, and add about half an inch of water to cover it. Cook the rice on stove with lid closed until the rice is cooked thoroughly. Add some water during cooking if it seems to be going dry, to avoid the bottom getting charred.
- Let rice cool to room temperature
- Pulverise two yeast balls until they become a fine powder. Keep it dry and in a bowl.
- When rice is cool, spread a layer about half to one inch thick at the bottom of the glass jar. Best to have a jar with a wide mouth. Sprinkle some yeast on top. Repeat until all the rice and yeast are used up. You could stab it with a fork while layering to help mix the yeast in better, and to remove large air bubbles.
- Leave in a dark, warm-ish place with the lid closed but slightly loose, so dust and vermin stay out but gas can escape.
The speed which this works depends on the temperature you have at home. It is winter now where I live and I like to keep the thermostat down to save money so the fermentation might have gone much faster in a warmer place.
After one or two days, some liquid already began to accumulate at the bottom of the jar. The yeast digests the starch in the rice to free sugars, which it then ferments to alcohol. The solid mass of rice stays floating on top, buoyed by the bubbles of carbon dioxide also being produced (hence the loose lid).
A layer of white mold also formed on the top and started sporulating in patches, after two or three days. I was at first concerned but learned that this was a consequence of the top drying out. I pushed down the dry top layer with a knife, and sprinkled some water on top to keep it moist. At the same time I tasted some of the rice mash and it was remarkably sweet and tasty, with a fruity aroma.
By the second week about half the volume was taken up by the liquid, and the aroma had an alcoholic and slightly acidic tang to it. I put the jar in a cool cupboard to slow things down, because it did not fit into my modest fridge.
Finally, the weekend came round and it was time to see if all this worked out. In place of a cheese cloth for straining I used a plain cotton diaper (unused, of course), which I had briefly boiled in water to remove any sizing and dust. We tipped the mass out of the jar, and strained it through the cloth into another pot. The mash was spongy so quite a bit more liquid could be recovered by squeezing. This was then funneled into glass bottles and refrigerated. The total yield was just under two 330 mL bottles.
And the taste? I was initially skeptical because the top of the mash was already sour and I thought it had gone off to vinegar as we had waited too long. However, it turned out to be a sweet wine with a slightly tart hint to the fruity taste. The rice flavour was present but not overpowering. Definitely alcoholic, though we did not have a means of measuring the percentage, but not fizzy. The wine was cloudy, and still full of live yeast and starch grains, which we could see under the microscope. What it reminds me of is a rice-y young wine, or Federweißer, which is also full of yeast and actively fermenting.
I had read that the rice solids could be used for cooking, but because these had already started to sour I decided not to do so. I think that the earlier stages, e.g. after about a week when it is still predominantly sweet, would be more suitable for cooking.