Craig A Qualls wrote:
I real enjoyed your article on the production of Sake, I found it easier to follow then the article from Spangol's Wine making handouts written by Fred Eckhardt. I find no real criticism of your article except for the temp that you suggest to place the koji (latest style yeast mash) Day two) at a 122 degrees. Most cultures of this type cant survive temps of a 104 to 107 degree for a prolonged time.

GEM Cultures is still in business they sell the Light Rice Koji Culture in powdered form for around 2.50 which will make a minimum of 2.5 pound of Rice Koji if you know what you are doing you can get a lot more.

GEM Cultures
30301 Sherwood Road
Fort Bragg, CA 95437
707 964 2922
www.mypage.mainone.com/gemculture

I have tried the web site and have not been able to open it, but have ordered cultures form them and they are good.

Craig A Qualls

We're trying to make koji and sake. We've been using the procedure in Fred's book, and your summary of it in the following post. (The summary is very helpful. Thanks a lot.)

We bought some koji starter from GEM Cultures, and set out to make 5 pounds of koji. Well, we overheated it on day 2, and we'd never seen *real* koji, so we didn't know what we had.

We had the good folks at GEM send us 2 packs of koji (3 #'s), and the industrial sized packet of koji starter(40 gramms). We mixed the asperiligus culture w/ flour in the 1:10 ratio (440g), (over) cooked our 5 pounds of rice, and again over heated it on day 2. (DOH!!!) This time, since we had a quart jar full of koji starter, we simply re-innoculated the koji. Trouble is K1, K2 and the GEM Koji are all slightly different. K1 has a slight gym sock aroma (as does the GEM Koji) while K2 seems to be clean, but is oh-so-gummy from the over done rice.

Any advice on Koji making? Have you done it? The 3 we have are similar, but not the same. We plan to make 2.5 pounds this weekend, since we don't have enough GEM Koji for the entire batch.

On to the sake. We're in the tale end of the yeast mash, started chilling it this a.m., and plan to begin the main mash on Sunday. We're wondering what temp we should keep the main mash at? The book mentions having it at 70^F to begin with, and at the finish, but 23 keep doubling it by adding the 85^F mixture of rice and water.... Do we want to keep the main mash at 70 during the rice additions? Will we need to cool it to do this? The yeast mash is in a gallon jar, and we've been using a water bath w/ an aquarium heater to monitor and maintain the temps.

I think the main mash is good. It smelled of rotten eggs prior to adding the Wyeast. The yeast took off, and now it smells strongly of very healthy happy yeast.

We are wonding about damage to the yeast due to cooling the mash. I know that with lagers, they recommend a very slow cooling. I also know that temperature shocks can stunt and even kill yeast. Do you have any thoughts on how fast we can chill or warm the yeast?

Sorry for the rambling.

Cheers,

*  James Lee (Jim) Ellingson                     jellings@me.umn.edu  *
*  University of Minnesota, 125 Mech. Engr.         tel 612/696-0260  *
*  111 Church St.SE, Minneapolis, MN 55455          fax 612/625-8884  *

the Outsider's Response

Well, it's interesting to see that our sins live on, long after we've forgotten them! As you can see, my long ago posting was almost 2 years ago, so perhaps my memory of what I had done is a little, well, rusty. However, I'll try to answer what questions you had...

I did 2 batches of sake in sucessive years. The first time, I used commercially prepared koji and random wine yeasts, while the second time, I made my own koji and used Wyeast sake yeast. I didn't have a steamer, so I was unable to steam rice, therefore I boiled just like I would according to directions on the rice bag. When I made Koji, as best I could according to the directions from GEM, I used a big cooler (my beer grain mash tun in other incarnations) with a variable resistor controlled light bulb for a heat source. I tried making my own power cord, but that only shorted out the outlet's circuit! The next time I went to the hardware store and bought a control circuit used for adjusting the power to lamps. Using this, I was able to adjust the power to the light bulb, which functioned as a heater inside the cooler (I worried about the light sensitivity of the koji, so I encased the bulb in a can, a jar, and a cloth. I don't know if that was necessary, but I did it anyway...) Every once in a while, I'd peek into the cooler and check the temperature. If it was too hot, I'd turn the lamp down a bit more...

When all was said and done, it looked like the rice was covered with a greenish/brown sort of slime. It was VERY different from the commercial koji which I had purchased, but I used it anyway. I put the rice that had been slimed into zip-lock bags, and put them into the freezer, taking them out to thaw as needed in the sake schedule.

As far as your temperature schedule goes, you'll have to wing it! There shouldn't be any problem with temperature shock as long as the yeast is being introduced into a warmer environment than it already is, which is to say it's OK to heat up the yeast, and it's probably OK to do that quickly. (Temperature shock is only a problem when introducing the yeast into a COOLER environment...) The way I interpeted Fred's stuff (and believe me, there is a LOT of interpetation required!) is that the temperature should be close to 'room' for the yeast, although the koji would like the temperature to be closer to 'blood' or even warmer. One reason that sake takes so long is that the koji (aspergil) mold supplies enzymes that would enjoy a higher temperature, but that temperature would stunt or even kill the yeasts. Therefore, a compromise is made so that both yeast and enzyme can work at the same time, i.e. in my closet. I didn't worry too much about the temperature being 70 vs 65 or whatever. I just put it in the closet and stirred it when I could. (Doesn't every stirring every 2 hours over 24 hours sound like much? I need more sleep than that!) In any case, as long as the yeast, asp. enzymes, and rice are all in a happy little environment, then all should be fine.

All of the above should be taken with the proverbial grain of salt. My sake experiments came out OK, if not outstanding. I only have the advantage of experience, but not perfection, or even much practice! Find what works for you and go for it! And I hope that this helps...

If you have any more questions, feel free to communicate. I love telling people how ignorant I am!

Good luck with your experiment, and let me know how it turns out...
Rich Webb

Thanks for the insight. Your Koji sounds more **interesting** than either of ours. I admire your fortitude in going ahead w/ it... Good to hear that it was drinkable anyway. Was either better than the other?

I try to take your approach in brewing. It ain't rocket science. Treat your enzymes, yeast w/ a little respect, and all should be fine in the end..... After 50+ batches and 600+ gallons, I hope I've learned what to get excited about. :)

We popped for a 35 cm double decker steamer. It's too big to fit on the stove, but it can make nice "nutty" easily seperated rice. (It can also make mush, but that's another story = K2).

We got a very nice SS food tray form Superior Prods. We keep it in the oven. The idea is to run the electric oven up to 150^ F once in a while to get it up to temp. W/ K1, I had the thermometer in the middle of the big ball o' rice. By the time the center was warm, the outside was "cooked". W/ the second one, I forgot to turn the oven off on my way out the door in the a.m. Oh well. The house smelled great after that!

Neither batch is as white as the GEM koji. K2, w/ it's double dose of starter, is the darker of the 2. Neither was "slimy" although K2 was gummy. K1 is inconsistent. Some of the kernals are whiteish (Like the GEM description) while most are grey/green.

Am curious how you pressed the lees, if you used any finings, and what size batches you made....

Also, did you pasturize at day 51, age 2 months, bottle and age 2 months? Was aging important?

Thanks again for the very informative post. Will try to keep you posted the the sake.

Cheers,
Jim