Recent Posts



No tags yet.

Let's Talk About Yamahai-Moto

Our online homebrewing communities sure have come a long way, haven't they? I mean, especially when it comes to the availability of good information about brewing saké. When I started homebrewing in 1999, there was exactly one resource - Sake U.S.A. by Fred Eckhardt - that was already out of print at that time and I only came into by sheer chance and a very generous friend. Then came my realization in 2006, amid a surge of online homebrewer community interest in the subject, that the existence of sake brewing information online was exactly nil.

That's when I wrote my first article, in fact.

Now, everywhere I look, there are saké recipes! Ten years later and the recipes for legit nihonshu finally outnumber the old recipes for doburoku! There are even a few places to get honest-to-goodness saké ingredients from. My friends, through the passion of some special brewers in the community, we've done it! We've changed the Internet for the better.

You guys have made me proud!

But guys, seriously, we need to talk.

Why are you so afraid of yamahai moto?

I'm serious! Everywhere I look, recipes are relying on the shubo method to quick-start the moto!

And that's a damn shame, in my opinion. My fellow homebrewers, beginners and advanced alike, are cheating themselves out of the opportunity to add additional character and complexity to their saké, not to mention losing out on the experience of using a traditional method.

Just breaks my heart to see it.

Madness, You Say?

Now that I'm finished ranting, let's get down to business. I'm not going to go into the history of the yamahai moto method, because John Gautner is an authority on the subject and has already done a great job of relating that history in this post on his website.

The goal of a yamahai moto starter is exactly the same as sokujo moto: increase the acidity of the starter enough to discourage spoilage organisms from taking up residence. Where this method differs, however, is in its reliance upon the ubiquitous lactobacillus family of acid-producing bacteria. If you think about it, you'll see that we're employing exactly the same technique used in creating sourdough starters to cultivate just the right bacteria and wild yeast in our starter to sour it so that other, less desirable, critters can't get in there and spoil it.

Such madness! Why would we do such a thing?!

The nuance of flavor and aroma, that's why. Just like a good sourdough bread starter, our friends the lactobacillus bacteria aren't the only ones present in the moto: other complementary wild critters unique to your brewing environment also set up shop and, along with the lactic acid bacteria, produce the esters and phenols that will give each batch of saké it's final "house" character.

For half a century, this was the starter method of choice for Japanese saké brewers

It's a little more effort, yes. A little more time is required, as well. It also introduces more risk of spoilage, this is true. But the unique character produced in the final product is exactly the reason for the continued existence of sakagura who still use the labor-intensive yamahai moto and kimoto methods for their very best saké.


Ready to try it yourself now? In addition to your normal saké brewing equipment (full list here), you will need:


  • Temperature controlled environment capable of 50ºF/10ºC

  • pH test strips - Wine range (2.8-4.4)


  • 2.50 cups (591 ml) - Water, filtered

  • 0.75 ts (3.70 ml) - Yeast nutrient powder

  • 1.00 pinch - Epsom salt (magnesium sulfate)

  • 0.50 cups (118.29 ml) - Kome-koji (koji rice)

  • 1.50 cups (355 ml) - Rice, short grain sushi variety

  • 1.00 pack/tube - Sake Yeast, preferably WYeast WY4134


These directions assume a certain level of saké brewing knowledge and don't cover basics like steaming rice in favor of focusing on the yamahai moto starter method.

Day 1

Throughout the first two days of this process, keep the fermentation vessel someplace where it will stay in the 68-76ºF (20-24ºC) temperature range.

  1. Clean and sanitize your primary fermentation vessel, lid, airlock, spoon, measuring cup, and anything else that is about to come into contact with your moto.

  2. Add the following ingredients from the above ingredients list to your vessel:

  3. 2.50 cups (591 ml) Cold water, filtered if possible

  4. 0.75 ts (3.70 ml) Yeast nutrient powder

  5. 1.00 pinch Epsom salt

  6. Stir until all of the powder is completely dissolved, then stir in the 0.50 cups (118.29 ml) of kome-koji.

  7. Cover and set aside overnight.

Day 2

  1. Soak and steam 1.50 cups (355 ml) Sushi Rice in the usual way for saké.

  2. Add the hot steamed rice to the fermentation vessel containing the koji and water mixture.

  3. Stir thoroughly with a sanitized spoon or your sanitized hands.

Days 3 - 4

The lactic fermentation of the starter has begun! Your only jobs are to stir and monitor the starter.

Do these steps twice a day for two days:

  1. Stir the starter with a sanitized spoon.

  2. Test the pH of the starter. We're looking for the pH to drop to about 3.6-3.8.

  3. Smell the starter. A sour smell is expected, and fruity smells wouldn't be out of place. I have never had a yamahai moto starter go bad, but if it does you will know it. If it smells rotten, putrid, or reminds you of garbage or vomit, throw it out and start over.

  4. Taste the starter. If it smells okay, go ahead and lick your spoon and make sure the flavor is headed in the right direction. Sour and funky is okay; putrid or rotten is not.

Day 5

Once the pH level has fallen below 3.8, add the yeast and move the fermentation vessel to cold storage and allow it to cool down to as close to 50ºF (10ºC) as you can get it. Cooling down will take some time, so here it will stay until the next day (about 12 hours).

The Science:

We're using yeast's comparative hardiness to our advantage here, as Saccharomyces cerevisiae is far more tolerant of this low temperature than the wild microorganisms that have been souring the moto so far. The bacteria will go dormant as the temperature falls, but the yeast will remain active enough to begin building up a population.

Process steps:

  1. Pitch the yeast, then stir it in with a sanitized spoon.

  2. Move the fermentation vessel to cold storage and allow it to cool down to 50ºF (10ºC) for 12 hours (overnight is fine).

  • DO NOT SKIP THIS STEP! Cooling the starter down is critical for pushing the currently rampant lactobacillus bacteria into dormancy so that the yeast can take over.

Day 6

Time to let the yeast kick into high gear.

  1. Move the fermentation vessel to warm storage and allow the starter to warm back up to 68-76ºF (20-24ºC).

  2. Maintain this temperature range for 5 to 7 days.

  3. Stir the starter with a sanitized spoon once a day during this period.

Day 10~ish

Keep an eye the fermentation activity of the starter. Fermentation will likely complete somewhere around day 10 or 11, which will be apparent by the decreased bubbling in the starter. Once the starter has reached this point, move it back to cold storage and keep it there for at least 5 days.

Use this maturation period to begin preparation for the main moromi build-up.

Day 14

Congratulations! You now have a completed yamahai moto starter that is full of character unique to your brewery! The wait is over, today is the day you begin the first addition of the moromi build up.

From here, proceed with the same steps as any other batch of saké.

It's Risky, I know...

Don't let the notes about the risk of spoilage scare you off: I have used this method for every back of saké since 1999 and have never had to throw one out. In my experience, however, good home brewing sanitation practices along with the ubiquitous and vigorous nature of lactobacillus will prevent just about any gram-positive spoilage organism from ever gaining a foothold in your starter. The risk of a spoiled starter (and wasting ingredients) is minimal.

Does yamahai moto add more time and effort to your saké process? Well, yeah.

Is it worth it? Very much so, in this brewer's opinion.

Brewing saké, like baking bread or brewing beer, rewards both the technical and the artistic. One must have both to truly excel.

Until next time - 乾杯

This site was designed with the
website builder. Create your website today.
Start Now