Making Koji for Sake

Making Koji for Sake

In order to make koji for brewing sake we need to go through the same steps that we do to prepare rice for brewing sake. In fact, it is often the case that a portion of the rice goes directly into the brewing sake while another portion is used for koji. So, as always we begin by washing the rice. This is to remove all contaminates, including the powder (Nuka) that remains after milling and any material added by the miller, like iron. Removing the nuka lowers the stickiness we will have after steaming. And, as mentioned elsewhere, iron is very bad for sake as it darkens the sake and speeds a reaction of residual sugars with amino acids that harms the flavors and aromas.

Washing the rice is followed by steeping the rice until we reach the desired water uptake level, usually between 25% and 35%. If the uptake of water is too little the rice will not steam properly leaving a hard uncooked center that the koji mold will not penetrate. On the other hand having too much water uptake will cause the rice to be too mushy and sticky after steaming. This results in a base that is too easy for the koji mold to penetrate and this prevents or lowers the production of transformative enzymes we want. Most rice used for hombrew sake will need to steep between 30 minutes and two hours. As homebrewers we are more often than not more guilty of soaking too much than too little. Continue reading “Making Koji for Sake”

A Pictorial Look at the TwinBird Rice Mill

A Pictorial Look at the TwinBird Rice Mill

Back in August I posted an article about milling rice with the TwinBird Rice Mill. However, I was not able to include any pictures that could prove useful to those of a mind to construct their own mill. I committed to doing so and I now have the needed pictures.

As we shall see this arrangement seems like it can point the way to a very workable small rice mill that would handle, say, 20 lbs. of rice. Anyway, let’s take a close look at this baby. The TwinBrid mill is designed to run in the kitchens of Japan, handles 4 go (180ml) of rice at a time and runs on 100 Volts, 150Watts at 50-60 cycles. This makes it a good fit for US kitchens as well. The picture below shows the mill and its control panel. The left side is used to indicate the starting state of the rice to be milled, from white rice at the top to brown rice at the bottom. The right side is used to indicate the level of milling desired. Given this, I believe the setting shown gives the longest mill time setting.

TwinBird Mill
TwinBird Mill

Continue reading “A Pictorial Look at the TwinBird Rice Mill”

So you like the Honjozo (本醸造)

This article discusses how to make Honjozo sake.

There is a lot to be said for Honjozo. It tends to be light and fragrant and can be exceedingly smooth. I was ecstatic with the first honjozo I tried. It was the Murai Family Tokubetsu Honjozo, light and smooth, fragrant but disappeared like a ghost. Very nice. Since then I have had other honjozos but this one remains one of my favorites.

Honjozo is a Special Designation Sake just as Junmai, Junmai Ginjo and Junmai Daiginjo. In fact Ginjo and Daiginjo without the Junmai designation are both honjozo. You can think about these special designation sakes as having three grades of Junmai (pure) and three parallel grades of Honjozo (brewer’s alcohol added). The top rung, Daiginjo, is one where the rice used has been milled to 50% or less with one pure and the other with added alcohol. The next rung, Ginjo, is with the rice milled to 60% or less with one pure and the other with added alcohol. Finally the entry rung to the special designation sake is Junmai (pure) and Honjozo (brewer’s alcohol added). When this system was put in place, to make this entry rung, the rice used had to have been milled to 70% or less. While this is still true for Honjozo, the milling requirement has been remove for Junmai. Continue reading “So you like the Honjozo (本醸造)”

Milling your own rice with the TwinBird Mill

This article discusses how homebrewers might use the TwinBird Mill to polish / mill their own rice for homebrew sake.

Rice milling is arguably the first step in sake brewing. For some, it may be the rice harvest or even the entire process of growing the rice. Then for others, most home brewers, milling is not much more than the story we hear about how the pros do it.  However, under the current situation this is hardly acceptable. As home brewers, we have, to my knowledge, only two options for milling levels; standard white rice (approximately 91-93%) and a rice milled for Ginjo grade sake (60%). For those who would like the chance of brewing other classes of sake other options are needed.

TwinBird MRD570
TwinBird MRD570

Recently, I got a rice mill from Japan; the TwinBird Mill. It’s not meant for sake but for home use with table rice. I was not sure that it would be able to mill the rice down as much as I wanted. That is that it would be able to mill rice to level far past those used for table rice. I wanted to be able to have rice ever where from table rice levels (about 90%) to daigingo levels (less than or equal to 50%). Maybe even lower levels. Could the TwinBird do the trick? The short answer is yes, but… Continue reading “Milling your own rice with the TwinBird Mill”

Sake Acidity – Sando ( 酸度 )

Article discusses sake acidity (sando).

The acidity of a sake or its sando is a measure of how much base liquid is needed to neutralize 10ml of sake. Acidity in sake balances its sweetness. The sweeter the sake the higher its acidity can be without being sour or annoying. In general the higher acidity the thinner the sake will seem. However, as with all the characteristic parameters of sake, we cannot say that a sake with a high acidity level will seem thin, only thinner than if it had lower acidity.

Acidity levels tend to range from 0.8 to 1.7. As we saw previously, the nihonshudo values (SMV) tend to be between -5 and +10. Using these two metrics together is more useful than individually. Recall that the more negative the nihonshudo value the sweeter it is and the more positive the dryer it is. So producing a sake with SMV -4 and acidity of 1.7 (two extremes) could create a heavy dry sake; that’s right, dry. This is because the acidity balances out all of the sweetness. We must keep in mind that these are only trends and not absolutes. In the same way, if we produce a sake with high SMV of +7 and a acidity of 0.8 may be sweet and thin or watery. Continue reading “Sake Acidity – Sando ( 酸度 )”

Preparing Your Rice for Sake Brewing

This article discusses the process of preparing rice for brewing sake or making koji.

An important step performed several times during the sake brewing process is the preparation of the rice. We prepare rice for the moto, then again for each step of the san-dan-jikomi, the three step addition of rice, koji and water to build up to the moromi or the main fermentation. Another addition is sometimes done new the end of moromi called yodan. The preparation of the rice is the same for each of these additions.

Rice preparation consists of washing, rinsing, soaking, draining, packing, steaming, cooling and finally adding it to the brew. Rice for koji also goes through the same process except rather than adding it to the brew it is inoculated and then incubated. But this will be covered in another article. Let’s cover each of these steps separately. Continue reading “Preparing Your Rice for Sake Brewing”

How Sake is Brewed

Brief introduction to how sake is brewed.

Sake is brewed in a strung out process that can take quite a long time but none of the steps are particularly difficult. In the traditional method, brewing sake starts with the rice and its milling. The objective is to remove the outer layers of the rice which cause sake to be less stable and to have harsher flavors. These layers contain the bran and the highest concentrations of oils, fatty acids, proteins and minerals like magnesium and iron. Table rice (white rice) is generally milled to around 93% of its original size. Sakemai (Sake Rice) is usually milled somewhere between this for futsu-shu (table sake) and 35% for the most refined Daiginjo. Removing these components leads to a more stable and refined sake.

Once the rice has been milled to the proper level we need to steam the rice. We used steamed rice both for making koji and to directly add to the brew. In order to steam the rice properly we need to first wash the milled rice to remove the outer layer of rice flower, talc or whatever may be on the rice. After a good washing the rice is soaked to absorb the needed amount of water for proper steaming. This amounts to about 30% by weight. The higher the milling rate the faster the rice will absorb the desired amount of water. Kurabito (brewery people) working with the most highly polished (Milled) rice often use a stopwatch to time the soaking period so the rice does not take on too much moisture. Here the goal to get enough moisture into the rice so that the steaming process gelatinizes the rice by heating the water already there. If the rice has too much moisture it will become soggy / mushy during the steaming process and will not form a nice home for koji. Continue reading “How Sake is Brewed”

Some Koji History

A little history on Koji

Koji has been used in the orient for two to three thousand years. Its use on a substrate of rice, soybean and wheat bran seems to have originated in China. Use of koji migrated to Japan in the Yayoi period around the change in the western calendar from BC to AD. Somewhere in the Heian and Muromachi period between the thirteenth and the fifteenth centuries AD koji became commercially available.

This was, in part, possible because of the use of hardwood leaf ash. These leaves where burned in an environment with limited oxygen to produce an ash/charcoal that was protective for the koji-kin. Koji-ken base packed, layered, in boxes with a layer of koji-ken then ash and repeated. The use of ash in packing to preserve the koji-kin led to the discovery that adding the ash directly to steamed rice produced more consistent koji production. We now know the alkaline environment from the ash prevents other micro-organisms from getting a foothold and that the minerals in the ash help mold growth.

Moyashi or fermentation starter suppliers, two of them, were established in the Muromachi period about 1400AD. The Koji-za did not license more than these two prior to 1700AD. Currently, there seems to be about five such producers.

Koji What?

This article discusses what koji is and what it contributes to sake.

The most mysterious ingredient use to make sake is koji. What is it? Why is it so important? What does it contribute to sake? Well, these are all important questions we will address here. Koji is a general term that is almost always used as a specific term by those talking about sake. In the general case koji is some kind of substrate with some kind of mold growing on it. How’s that for a technical description. Koji used for making sake is, in most cases, yellow koji consisting of  Aspergillus Oryzae growing on milled rice.

Yellow koji is also used for making Shochu, a distilled beverage, but has been mostly replaced by other forms of mold and substrate. The two most common molds now used for koji in the production of shochu are Aspergillus Kawachi (white) and Aspergillus Awamori (black). In the general case the substrates also very quite a bit. Substrates of buckwheat, sweet potato, barley and rice are common. Rice is always the substrate used for sake. Continue reading “Koji What?”

More Sake Yeast

This article contains information on the yeasts that the Japanese Central Brewers Union collects and distributes.

Last week I wrote about sake yeast but the post got to be longer than I intended so I cut it short. I left off a little of the more commonly mentioned information about the yeast strains collected and distributed by the Central Brewers Union.

You may recall from the last post that back in the early 1900s the Central Brewers Union in Japan started collecting pure strains from particularly good batches of sake. The Central Brewers Union then made these pure strains available to all breweries. These pure strains where given numeric designations. So far there are from #1 to #16 and the low foaming strains. Many breweries now use these yeast strains but many also use of private strains. Continue reading “More Sake Yeast”