How big should my MOTO be?

I just set out to make my first batch of sake, following BoB Taylor’s instructions (Yamahai-MOTO-style). And I’m running into some questions.

In making beer I adjust the volume of my starter to the batchsize I intend to end up with.
Should I do the same in making the MOTO?

Let me scetch the details:

I want to make a 22 Liter ( ) batch of sake.
I have prepared 2,4 Kg ( ) kome-koij
I have just smacked a WYeast Aktivator 4134 #9 Sake Yeast pack.

How big should my MOTO starter be?

The recipe that I’m following here is Bob Taylor’s.
In this recipe he aims at 11 Liters of sake, using 1 pack of WYeast.
This amount of Yeast (straight out of the smackedpack I guess), combined with 2,5 cups of water, 0,5 cup of Koij and 1,5 cup of rice makes up the MOTO for his intended 11 Liter-batch.

Is Bob taylor referring to an Aktivator or Propagator in this recipe?
Would the MOTO he describes be sufficient for a batch twice the size?
Should I not double the size of the MOTO, since I want to arrive at twice the batchsize?
If so, will my XL Aktivator #9 be adequate for this job?

Any advice would be highly appreciated,

You should be fine scaling everything (with the exception of the yeast starter pack) by two. I followed Bob’s instructions but scaled everything up by 10 (except the yeast pack) and the result was excellent. I used koji and polished sake rice from FH Steinbart and good spring water…

My reasoning is that the whole point of the starter is to capture some yeast (originally from whatever was in the environment, they didn’t know about yeast back then) and give it a chance to propagate up to the optimal population counts and activity for subsequent rice and koji additions.

Thanks Chuck,

You just saved my day!
Didn’t know how to proceed actually.
Now I know I can confidently go with the one XL #9 smackpack.

Another question presents itself though: I am in the process of growing Koji right now.
I am in doubt whether to wrap the process up in plastic bags tonight (and put them in the freezer) OR let the little koji-thingies have their go at the rice for another 20 hours or so (for I won’t be able to harvest in the meantime due to work, kids andsoforth).

The kome-koji started sprouting little tentacles, I guess 12-20 hours ago. I just tasted some of the rice, and it tasted absolutely sweet. Not sweet like a sugargrain, but defenitely SWEET. Now I don’t know if that is anything to go by? I mean, sweet tasting rice: does that mean the koji-kin has done it’s thing?

By the way, I tried cutting a ricegrain in the middle and see how far the koji-kin “mold” had eaten it’s way in, but I can’t really tell.

again, any advice would be very welcome

How long has the koji been growing? If your rice is all covered white and it tastes sweet, then I’d say its ready. Should be somewhere between 36-60hrs or so.

Don’t let it go green on you. When the koji is to the point of being done, spread it out on an oven tin and heat for an hour around 120 or so. Dry it out as quickly as you can. Then store either in a tub in the fridge, or in the freezer up to a year or so…

I’ve placed completed good koji directly into gallon zip-lock freezer bags to just have some of the koji spore because (I scared the crap out of it) the freezer didn’t drop the temp fast enough in the bags :slight_smile:

Hello Dray,

This Koji has been growing since last saturday (55 hours ago), but I guess I heated too much in the beginning. I have a temperature contolled fridge, and I guess the hot-air vent was directly heating the bottom of the kettle I’d put the koji in.
The Koji had become too hot (and dehydrated I guess) and the spores didn’t do much of anything.
The actual process of “growing” started some 30 hours ago after I’d spinkled quite a bit of water on the lot.

Anyway, I’ve just freezed the Koji in plastic bags and put them in the freezer.
It was then that I read your post. So I did NOT dry them beforehand.

I sure hope the Koji freezes in a satisfying way, but I now understand there might be a problem there.
Is there any way of telling the Koji survived in good shape, once out of the freezer?

and thanks for the reply Dray,

The koji itself is pretty much done when you freeze it. As long as its white to light yellow it should be fine. Green means spores - mature koji which is not good for Sake.

Freezing is fine. At this point, the enzymes left in the koji are needed. I’ve just observed my koji going from good to over-done in just 8 hours. I didn’t cool it down enough or arrest the mold from growing any more. It took about 8 hrs inside those bags I used. Since the mold was still generating heat, it fought off the freezer long enough to finish maturing.

Once frozen, the mold won’t grow. You could take out some frozen and thaw it and bring it up to incubation temp. But the mold won’t grow, instead it will mature and spore.

You will know how well its working when you make the moto.

For what it’s worth, I add frozen koji directly to my fermenter. No thawing required.

Yes, I too add the frozen koji to the moto.

If an experiment wanted to be done to see if the koji is killed by the freezing, thaw it out and incubate it. I don’t think I made that clear in my previous post. Another contributor did this very thing and was able to make it go to spore I believe. Its pretty hardy stuff. Basically you want the koji to grow but not mature ie: begin to spore.