Having accomplished kome koji, I proceeded to attempt to make actual sake.
The first thing to realize is that sake is usually made in the colder months so the fermentation process can be kept at a lower temperature (a longer brewing cycle usually produces better flavor). Correspondingly, my first mistake was to attempt to brew sake during the summer, when the temperatures are about ten degrees (C) warmer than they ought to be. It's far too late to put this off, now, so we press on.
- 1500g of short-grain (sushi) rice were well rinsed, soaked for ~4 hours and drained/dried for another hour.
- The two levels of the bamboo steamer are loaded up with the rice (atop cheesecloth, as is necessary to keep the grains from falling through the slots in the bamboo) and steamed for yet another hour (I think I actually steamed mine for 1.5 hours owing to the fact that I had to peek every so often to make sure the water hadn't boiled away).
While the steamed rice cooled (which took another couple hours) I started working on my temperature problem. I had to figure out someway to keep the brew at ~15C. I considered building a small chamber and using an air conditioner to maintain temperature but dismissed it as ridiculous. I also considered re-purposing my basement fridge (a small, dorm sized fridge, mostly used for keeping beer cold) but I was unable to come up with a container that would be large enough to hold the ~4L brew and also fit inside this tiny refrigerator. I finally decided to put the brew in a (cleaned and sanitized) 14L plastic Stearlite container which would then fit into a [so-called] Extreme cooler. I can periodically add ice (or frozen water bottles or whatever) to the cooler to try and maintain a reasonable temperature. Who knows if this will work? There's no air-lock on this fermentation vessel and I'm not even sure if one is needed! Again, we press on. To this fermentation vessel ("tub") add:
- 4L of filtered tap water,
- 5g of citric acid (I believe this retards the growth of undesirables),
- 400g of the previously prepared kome koji (malt rice),
- 1500g of steamed rice, and
- 5g sake yeast (I could have used any brewers yeast but I happened to have a bottle of White Lab's Sake Yeast; I have no idea if this will make a significant difference).
Mix it all up and let it go. I'll be mixing it up every day to check on the process and to try to keep the temperature in the right range (~15C) to extend the brewing process. In a couple weeks I'll filter it and then [hopefully] be able to drink it.
Addendum: I just noticed that on the White Lab's page for their WLP705 sake yeast they recommend a brewing temp range of ~23C. That should be somewhat more manageable with my ridiculous cooler system.