The first thing I ever brewed was sake! I read some all grain stuff and thought 'too much money and too expensive' and my roommate made the mistake of saying that his relatives make it all the time in Taiwan. I started doing research and found visionbrewing.com too.
I wasn't overly impressed with the first batch because there was way too much lemon flavor and acidity. Also, we had to drink the entire thing in the first couple days because I didn't know how to pasturize it. We got pretty drunk.
My current favorite sake procedure involves the following :
2-2.5 lbs koji, home made all at once, half frozen
3.5 lbs steamed rice
Korean brand short grain brown rice
Fleishman's Bread Yeast
bottled spring water
I soak the rice before I steam it.
I steam the rice in the stainless pot I use for fermenting, so its sanitized.
Once the koji is ready, and the rice is cooled, I add a gallon of spring water to all the steamed rice and about half the koji.
I seal it with the lid and wrap it up in Saran wrap to keep it nice and sterile.
I try to leave some small air holes for the CO2 to escape.
I let it ferment in a dorm fridge on the lowest setting (~60F) for about 2 weeks.
I take it out once a day and give it good agitation without unsealing it.
Usually agitating it results in lots of bubbles rising up from the rice at the bottom.
After 2 weeks, I thaw the remaining koji and pitch it in.
I let it ferment for another week or two and then drink it!
I pasturized it at whatever the recomended temperature was (130F for 5 minutes?)
I bottle it in beer bottles.
Once I did an experiment where I pasturized a bunch of it and then made 2 "specialty bottles".
One was still fermenting, so after about 3 days it was lightly sparkling.
One was fermenting unsealed.
The people that have tried my sake say it's good, and I like my sake better than most of the commercial sake I have tried.
The sparkling sake was well liked.
The one allowed to fermented longer was driest.
The pasturized sake was a little flat tasting.
One pasturized bottle was left in a fridge for a year, and was quite good when we tried it.
I recently learned that brown rice is exactly the opposite of what you should use since it still has its entire husk. Interestingly enough, soaking brown rice in water is supposed begin the germination process and releases GABA predicesor protiens/amino acids. It works well with mine. *shrug* I think mine tastes great with raw shashimi grade tuna and rice.
My vague understanding of the biochemistry of sake is that the koji mold produces alpha and beta amylase (that's what does the work in the mash for beer). The yeast float around and eat the sugars that the amylase produces. I cannot explain why the amylase works correctly at ~60 F, since the beer literature says it isn't active til near 155F. I would guess that the amylase probably works at the low temperature, but very slowly and inneficiently, but that's not really a problem because the yeast are working slowly too. I know that the koji rice itself is sweet (I've eaten some of it raw before, it's tasty, kind of like a sweet cheese), but I can't imagine that without some amylase action that 2 lbs of rice would produce enough fermentables for the high ABVs that occur.
Here are some potentially useful resources courtesy of brewery.org :
Hope that helps.