Anyone wanna make Sake?

Making Sake

Author:  Bob Taylor Issue: November 2008

Grains, water, yeast . . . and koji? Learn the secrets of making sake (Japanese rice wine) and get your moto rising.

 

When making sake, the first ingredient to consider is water, which is something we’re all familiar with. The water used for making sake should meet the same requirements that hold for beer: clean, good tasting and chlorine-free. If the water used for sake meets those requirements, minimal mineral adjustment will be necessary (more on that later). 

Rice, of course, is the staple food grain for all of Asia. Japan does not, under any circumstances, export their rice, so getting genuine Yamada Nishiki sake rice is out of the question for even the largest of North America’s sake producers. Fortunately, the US grows some excellent quality, hybrid, medium-grain rice. My personal favorite is Kokuho Rose sushi rice, which is grown in California, but any medium-short grain rice you can get your hands on will produce very respectable homemade sake.

Rice for making sake must be milled (polished) in order to remove the husk, germ and bran material. This causes a couple of problems when it comes to making a fermented beverage out of the grain. First, without these parts rice can’t be malted, so how can the yeast get the simple sugars they need to ferment our sake?

The answer is koji. A small portion of the rice used to make sake is incubated with the spores of a very specific strain of mold called Aspergillus oryzae. This mold is known for its ability to create a lot of amylase enzymes — the very enzymes we need to break down our rice starches and make them available for the yeast. Koji will very likely prove to be the most difficult product to find. Asian grocery stores in your area may stock Cold Mountain Rice Koji next to the miso in their refrigerator. If you can’t find that product, you can order koji-kin (koji spores) from Vision Brewing (http://www.visionbrewing.com/sake/) and produce your own koji.

The second problem is that polished rice is very poor in the nutrients that yeast need for a healthy fermentation — particularly magnesium and potassium. For this reason, the recipe on page 55 calls for some salts and brewer’s yeast nutrient, which are available at your local homebrew supply store or your local grocery store. These ingredients aren’t required — you can make sake without them — but they’re not expensive and omitting them will slow your fermentation down and alter the flavor of the finished sake.

Then there is the final ingredient: yeast. Wyeast WY3134 Sake #9 is my choice. In fact, it’s the second most commonly used yeast strain by professional sake brewers worldwide. White Labs also produces WLP705 Sake Yeast, which is available each year in September and October. Any neutral white wine yeast is also an acceptable substitute.

Gear Good to Go?

The list of required equipment is surprisingly short, and most of it is probably already in the average homebrewer’s equipment kit. You will need a racking cane, vinyl tubing, airlocks, one-hole stoppers and a plastic bucket fermenter, which are probably already in your inventory. Besides basic homebrewing equipment, you’ll also need a few pieces of very inexpensive specialized equipment:

• A steamer. Multi-tier bamboo steamer baskets are commonly available and dirt cheap. They need to be lined with a layer of cheesecloth to steam rice with them. For even cooking, don’t try to steam more than two tiers of rice at a time.

• One-gallon glass jugs. These will serve as secondary fermenters and clarifying vessels. I suggest having at least four of them to make rotating through them easier.

• A small fruit press. This device, while not required, will make pressing sake from the rice lees later on much easier. If you own one, use it. If you don’t own one, you can get away with using your hands to press the lees in a nylon paint straining bag.

How Sake is Made

The process itself is where homebrewers are tempted to take shortcuts. At first glance it appears very complex, labor intensive, and intimidating. It’s really not that bad! It helps to think of it as all-grain brewing, but with the mash and fermentation happening at the same time over a longer period of time. Like any other complex task, it helps to break things down into steps, and sake has three main steps with only one having a series of sub-steps:

1. Moto. This is a yeast starter. The traditional yamahai moto technique relies on using Lactobacillus bacteria to acidify the mash at this point, which is why pasteurization is important later on. The low pH helps to protect the fermenting sake from spoilage.

2. Moromi The primary fermentation, but to get a complete fermentation the mash needs to be built up in stages, with each stage doubling the total amount of the mash:

a. Hatsuzoe. First addition of koji, water, and rice.
b. Nakazoe. Second addition.
c. Tomezoe. Final addition.

3. Yodan The stabilization step where the nigorizake (cloudy sake) is separated from what’s left of the rice after fermentation is nearly complete. Water can be added to dilute the alcohol content, and the sake can be fined or filtered to clarify.

One final point of sake brewing that needs to be addressed is temperature control. The Japanese have a long tradition of only brewing sake in the winter months, much the same way German brewers used to brew. This is the “kan-zukuri” or “cold brewing” method. With modern refrigeration equipment, keeping to that traditional timetable isn’t strictly necessary, but for the homebrewer on a budget it can help.

Making sake requires frequent stirring, which means an open fermenter, so keeping the fermentation temperature as close to 50 ºF (10 °C) as you can get it during primary fermentation is necessary to keep the sake from becoming too sour from runaway Lactobacillus activity.

Steamed Rice

Rice needs to be cooked to gelatinize its starch before it can be used to make sake. When dealing with large volumes of rice, steaming is the preferred method of cooking. There are a few reasons for this, but it all boils down to ease of handling. It’s a lot easier to steam a large volume of rice than to simmer it, and the resulting cooked rice kernel is much firmer and less sticky than simmered rice, resulting in clumps that are much easier to break up. Steaming also volatizes and removes a lot of the fats that are still present on the outside of the rice kernel, resulting in a more delicately flavored sake.

The process for steaming rice is fairly straightforward.

1. Wash the rice thoroughly in cold water until the runoff is no longer cloudy.

2. Place the rinsed rice in a large bowl and add enough cold water to cover by about three inches. Place this in the refrigerator to soak for 8 to 12 hours, overnight is fine. During this time the rice will soak up the water that will actually cook it during steaming, so it’s important to get the right amount of water into the grain. Properly soaked rice is just slightly less than crunchy and breaks up easily, but is not squishy.

3. After soaking, allow the rice to drain in a colander for half an hour while you prepare the rest of your steaming equipment.

4. Place the drained rice in a bamboo steamer lined with cheesecloth (or whatever kind of steamer you own), cover, and steam for 45 minutes. Keep an eye on the water level in the steamer during this long steaming time and add water as required.

Step-by-step:
How to Make Sake
Starting with the moto, a basic batch of sake takes about six weeks to complete. There are many steps in the process, so it helps to keep a checklist and a calendar. Here are the basic steps, broken down, for making sake according to the recipe
on page 55.

Moto

1. Prepare 2.5 cups (591 mL) of cold
water by adding 0.75 teaspoon of yeast nutrient and a pinch of epsom salt. Stir until dissolved, then add 0.5 cup of koji. Cover the container and store it in the refrigerator overnight.

2. Meanwhile, rinse 1.5 cups of rice and cover with 2 to 3 inches of water. Place this next to the koji in your refrigerator and allow to soak overnight as well.

3. The following morning, drain and steam the soaked rice. After steaming, de-pan and mix the hot rice with the chilled koji and water mixture in your sanitized fermenter, using your clean hands (yes, your hands are the best tool for the job here) to mix and make sure all the rice clumps are broken up. The temperature of the mixture will fall to the 75–80 ºF
(24–27 °C) range.
Allow this mixture to remain at an ambient room temperature of around
70 ºF (21 °C) for two days, stirring twice a day with a sanitized spoon. Over the next 48 hours the koji will work its magic and the rice will almost completely liquefy.

4. After the two days have gone by, cool the rice and koji mash down to as close to 50 ºF (10 °C) as you can get it, then pitch the sake yeast. Hold the mash at this cool temperature for the next 12 hours.

5. Once the 12 hours have gone by, it’s time to allow the temperature to come back up to the 70 ºF (21 °C) range so the starter’s fermentation can carry out as quickly as possible. Stir the mash with a sanitized spoon twice a day for the next three days, then once a day for three days after that.

6. The basic fermentation of the moto is completed after nine days. The temperature should again be lowered to 50 ºF
(10 °C) and the moto allowed to rest for another five days. After those five days pass, the moto becomes ready for the moromi build up.

Moromi

In order to ensure a complete fermentation, it’s best not to add all of the rice and koji at once. Just like syruping a wine, gradually adding the fermentables coaxes the yeast into going above and beyond their usual alcohol tolerance. Rice, koji, and water are added three times over a period of four days.

Hatsuzoe

1. The first addition of rice will be
2.5 cups, which needs to be rinsed and covered with water to soak twelve hours before you plan to steam it. While you’re rinsing the rice, stir 1 cup of koji into
the moto.

2. The next morning, steam the rice for this addition. While steaming, dissolve 1.25 teaspoon of Morton salt substitute in a little warm water (this is the only time you will need to do this), then add enough cold water to make a total of 2.75 cups (651 mL). Place this in the refrigerator to chill until the rice is done.

3. After the rice is finished steaming, de-pan it and mix with the chilled water from step two. Use your clean hands to break up all the clumps and then, when the temperature of the rice drops below 85 ºF
(29 °C), mix it into the moto. The temperature of the moromi mash should settle somewhere in the 70–74 ºF (21–23 °C) range. Keep the mash at room temperature and stir every 2 hours for the next
12 hours, then twice a day for the next
36 hours.

Nakazoe

1. On the evening of the day after you started the hatsuzoe step, prepare 6 cups of rice for steaming. At the same time, stir 1.5 cups of koji into the moromi mash.

2. Steam the rice the next morning as usual, then de-pan and add 8.75 cups of well-chilled water. Mix well and, as before, add it to the moromi when the rice is sufficiently cool.

Tomezoe

1. Immediately following step two of nakazoe, allow the moromi to rest at room temperture for twelve hours, then stir in all of the remaining koji (20 ounces). Afterward, wash and soak all of the remaining 5 pounds of rice for the final addition.

2. The following morning, drain and steam the soaked rice. Work in batches if necessary, this is a lot of rice for even the most ambitious of steamers. The freshly steamed rice will need to be mixed with 1 gallon plus 1 cup (237 mL) of cold water before being added into the moromi.

3. Let the moromi, now at nearly 4 gallons (15 L) volume, rest overnight at room temperature. You can observe the odori or “dancing ferment,” which is sake’s version of the high kräusen that homebrewers are familiar with.

Now that the moromi is built up and fermentation is well underway, it’s time to get the temperature down. Move the fermenter to a location that will maintain it at as close to 50 ºF (10 °C) as possible and allow it to ferment undisturbed for the next three weeks.

Yodan

As the fermentation nears its close, it wouldn’t be a bad idea to keep an eye on the specific gravity. Once the gravity has dropped below 1.000, it is time to separate the sake from the rice lees (called kasu). Use a racking cane to siphon the cloudy nigorizake out from under the floating cap of kasu and into sanitized one gallon glass jugs until you can’t draw off any more liquid. Things will tend to clog up here, and that’s okay, you can just pour the remaining liquid and kasu into a nylon straining bag and use either your hands or a small fruit press to extract as much sake from it as you can. Aeration isn’t a huge concern here because there is still a little bit of active fermentation going on to help clean things up, but do try to keep things sanitary and splashing to a minimum.

Secondary, Clarifying, Maturing and Packaging

You should now have about three gallons of milky white nigorizake with an alcohol content somewhere between 18% and 22% by volume. Put stoppers and airlocks on the secondary fermenters and keep them at 50 °F (10 °C) so they can finish fermenting. In a couple weeks the cloudy rice particles will settle into a fluffy white layer of sediment on the bottom of each jug and you can just siphon the clear sake off into another sanitized vessel.

At this point in the process, you will have pale yellow sake that is no longer milky, but can’t quite be called clear. To render it brilliantly clear (and largely colorless), commercial sake producers use activated charcoal filters. For homebrewers, take a page from the winemaking book instead: bentonite. Used in a ratio of 1⁄2 teaspoon per gallon (3.8 L), bentonite finings will remove most of the haze from homebrewed sake in a matter of days.

To use bentonite, start with 8 fluid ounces (237 mL) of very hot water and slowly whisk in 1.5 teaspoons of granular bentonite. Once it has become a smooth slurry, divide it evenly between your containers of hazy sake, cap, and gently shake to distribute. In about three days, all of the bentonite will have settled out, taking almost all of the haze particles with it.

While you’re at it, there’s no reason why you can’t stabilize the sake by pasteurizing it immediately after adding the finings. It’s very easy to do. Place your jug of sake in a pot large enough to hold it plus a water bath, then add enough tepid (to avoid shocking the glass) water to come up to the shoulder of the jug (or the pot if the jug is much taller than the pot). Place a thermometer down the neck of the vessel and apply heat. Watch the thermometer carefully, and when it reaches 140 ºF (60 °C), remove the sake from the water bath, take out the thermometer, and cap the sake tightly. Allow the pasteurized sake to cool completely before refrigerating.

Once pasteurized, you can bulk age sake like this for up to six months before siphoning into smaller bottles and re-pasteurizing. Clarified, double-pasteurized sake has a shelf life of up to a year at room temperature, and considerably longer if kept refrigerated and away from light.

Conclusion

Once you know the technique, where to find the ingredients and have a few pieces of inexpensive equipment, making a batch of sake can be rewarding. For more information, visit my Web site http://www.
taylor-madeak.org.

Bob Taylor is a homebrewer from Anchorage, Alaska. This is his first feature story for BYO.

 

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