Koji-kin from Scratch, well sorta

How to make koji-kin for sake on your own.

One question I get fairly regularly is how to make koji-kin. Despite this I have failed to take the time to write up a good explanation for all of you. Well, no longer. In this article I will explain just what it takes and how to do it. Almost all you need to know is in my “Video Series and Instructions for making koji for sake” at: link. The only thing missing for making koji-kin from that source is that you need to sustain the last stage longer. That is, don’t spread out and cool the koji once it has completed its coverage of the rice. Rather, continue to monitor the koji so it does not get too warm or cold. It will start to show signs of a greenish yellow tint. This will progress into a darker greenish yellow color and begin to cover each grain. Once fully covered, carefully spread out the koji to cool. The green covering has lots of tiny spores that will come off so you’ll want to minimize disturbing it. After it has cooled, it needs to be dried so that other contaminates will not find it to be a nice home. Once FULLY dry, and I mean dry, you can place it in a shaker for later use.

The following picture is some koji-kin rice I have made. Some people will grind this into a powder but I’d use it as is.

Koji-kin rice
Koji-kin rice.

One way to use it is to put it into a shaker like the one in the following picture. It was purchased at a kitchen supply store and is often used for powdered sugar and the likes. It works well for koji-kin rice.

Koji-kin rice shaker.
Koji-kin rice shaker.

Using this shaker and koji-kin rice to shake over a piece of paper I get the pattern in the following picture.

Koji-kin from shaker.
Koji-kin from Shaker.

If you regularly make koji for your sake, you can, as needed, increase the batch size by 50% and after collecting and cooling the koji when ready, let the rest continue on as described above. This lowers the extra effort required for making your own koji-kin sense you were doing all most all the work needed already. Care must be taken to ensure the koji intended to continue on to koji-kin does not lose its warmth. Its smaller batch size will not hold its own generated heat as well as the larger batch.

Let us know if you make your own koji-kin and what your experience has been like!

Rice shinpaku structure or not?

Rice structure or not rice structure? Extending the review from last post with three more papers.

Key to sake production is the shinpaku or white opaque center. The shinpaku is generally important because of its increased ability to gelatinize during steaming, has a softer center for koji to invade once it breaks through the firmer outer layer, and is more highly convertible by the koji enzymes. All of this is true no matter the milling rate. For these reasons much of the breeding of new rice varieties has involved attempts to improve the significance of the shinpaku. However, as ginjo and daiginjo become more important types of sake, high millability is also becoming more important.

In particular, the papers analyze why some are better suited for high polishing levels while others are not. This characteristic is hugely important for ginjo and daiginjo styles of sake which have been on the rise in importance for some time now. This week I will look at three more articles on the same basic topic. However, before covering the additional papers, I would like to clear up a loose end from the last article.

The papers discussed in the last article, discussed the characteristic type of shinpaku each varietal has. These characteristic types include: non-lined (I think no-shinpaku would be a better name), lined, bellied, dotted, and ellipsoidal. As I mentioned in the article I was not sure what was meant by lined. Actually, I was thinking that it was a dense shell around the shinpaku. However, this was wrong. The lead author on the three papers, Masahiko Tamaki, sent me some nice pictures that make it clear. I don’t have permission to post the pictures so I will attempt to provide a diagram that gets the information across.

In the following diagram there are five characteristics represented with each having a side angle view of a rice kernel on the left and a cross section view looking down the long axis on the right. The first characteristic pattern, non-lined, represents rice without a significant shinpaku (white area in the center of the rice). Most eating rice has this characteristic. Next is the lined shinpaku which is the best structure for high milling levels. The bottom two bellied and ellipsoidal both have larger shinpaku but they are also more brittle. This gets in the way of milling and creates more broken rice. Dotted, is the final characteristic and is somewhere between non-lined and lined in terms of its suitability for high milling levels.

Rice kernel characteristics of shinpaku

OK, now that we have cleared up what was meant in each characteristic it is time to move on to the three additional papers. Masahiko Tamaki is the lead author for this set of papers as well. They are:

The first of these three papers looks at differences between rice kernels with shinpaku and without where the kernels are of the same variety. Two varieties (Senbon nishiki, Yamada nishiki) were analyzed each of which were grown in three different areas of Hiroshima (Shobara, Takamiya, Miwa).

The hardness of the center of each type kernel was measured with no significant difference between the three plots but quite significant difference between the shinpaku and non-shinpaku kernels within the same type. Other locations, four more, were also tested with similar results. In addition, starch characteristics were analyzed finding again, no significant difference between the shinpaku and non-shinpaku kernels. Given all this the conclusion continues to be that the differences in the structure of endosperm cells are responsible for all the properties of the shinpaku.

The second paper looks closer at the differences in hardness of the rice kernel and its shinpaku and their likelihood of breakage. They considered four types of rice: Kairyo omachi, Hattan nishiki No. 1, Senbon nishiki and Yamada nishiki. The first two of these have a significant higher breakage rate as compared to the second two. Very cool pictures taken with a Scanning Electron Microscope (SEM) show that Yamada and Senbon nishiki have much more tightly packed starch than does Kairyo Omachi and Hattan nishiki. This tight packing makes the rice harder and less susceptible to breakage.

Paper three analyzes the same rice varieties as paper two but compares starch properties rather than hardness. This study suggests that the shinpaku tissue may also play a part as well as the temperature of the early ripening period. This is, of course, in addition to the endosperm structure’s demonstrated impact on millability.

Hiroshima’s Hattan Rice Varieties best for Futsu shu but not Daiginjo

Hiroshima’s Hattan Rice Varieties best for Futsu shu but not Daiginjo

This week I thought that I would review a couple of papers on Hiroshima rice. I came across these papers on the analysis of Hattan rice which is grown only in Hiroshima. This piqued my interest because this rice, while only grown in Hiroshima, is sold to 32 Prefectures in 2003 and 24 Prefectures in 2006. I had never heard of this rice (not that this means anything) until I came across the papers so I kept reading to learn more. As it turns out Hattan varieties are well suited for futsu shu (standard table sake) because of the shinpaku (starchy white center in sake rice) but are not as well suited for Daiginjo because of the fragile nature of that shinpaku.

Masahiko Tamaki is the first author on each of the papers I will discuss today. Rie Kiharra and Takao Tsuchiya are also authors on all three papers. There are several other authors but they vary paper to paper. The three papers are:

  1. Varietal Difference of Polishing Characteristics and Suitability for Sake Brewing in “Hattan-Type Varieties” of Rice Suitable for Brewing Original Hiroshima Sake
  2. Properties of Starch and Protein of “Hattan-Type Varieties” of Rice Suitable for Brewing Original Hiroshima Sake
  3. Varietal Differences in Endosperm Structure Related to High-degree Polishing Properties of “Hattan Varieties” of Rice Suitable for Brewing Original Hiroshima Sake

Hattan type rice goes back to at least 1875 when private growers were breeding rice based on Hattanso.  Not long after this in 1907 the Hiroshima Prefecture Agriculture Experiment Station began working on producing better strains of Hattan-type rice. The primary goal for the improved strain was to produce rice with a more prominent shinpaku, better disease resistance, lodging resistance and higher yield. Initially, in 1921 this led to the development of Hattan No. 10. It had a low yield, was susceptible to lodging and rice blast and had a long culm, none of which are advantages. Despite these disadvantages it was used for breeding material. In 1962, this continued work produced Hattan No. 35 from Hattan No. 10 by introducing rice blast resistance. Later in 1965 Hattan No. 40 was bred. Much later, or much more recently, in 1984 two new varieties were bred from Hattan No. 35 by improving its yield; Hattan-nishiki No. 1 bread for hilly areas and Hattan-nishiki No.2 bred for altitudes above 400m. These last two both have the same high yield and lodging resistance as does table rice (non-glutinous rice).

The breeding program has succeeded in producing rice with larger grain size, higher percentage shinpaku and a higher percentage of the grains having this characteristic shinpaku. It also resulted in rice characteristics that are advantageous of sake brewing; better absorption of water and higher digestibility (that is the koji enzymes can convert more of their starch to sugar and protein to amino acids). These characteristics have made Hattan No. 35, Hattan-nishiki No. 1 and No. 2 well suited for sake brewing.

However, both Hattan-nishiki No. 1 and No. 2 are easily broken during polishing while Hattan No. 35 has a smaller harder shinpaku that is not easily broken. The level of breakage for No. 1 and No. 2 make them unsuitable for ginjo and daiginjo brewing, so only Hattan No. 35 is used for this. But Hattan No. 35 is by no means ideal because its cultivation characteristics are lacking.

It seems that one characteristic of the shinpaku between those that are fragile and those that are less so, is a “lined-white-core” or, in the terminology I have been using, a “lined-shinpaku.” I am not sure what a lined-shinpaku is, I will have to watch for more on this. Yamada-nishiki also seems to have just such a shinpaku, a lined-shinpaku that is.

The analysis in these papers show that the starch and protein composition of the various Hattan varieties are virtually the same so the composition does not account for the fragility. Maybe the endosperm structure can account for the fragility? The final paper looks at just this question. It concludes, yes, the structure seems to be the main cause. Hattan-nishiki No. 1 and No. 2 both have large shinpaku but also large number of interstices (gaps in the structure) while Hattan No. 35 has fewer gaps. In addition Hattan No. 35 has a lined-shinpaku while Hattan-nishiki No. 1 and 2 do not.

Comparing the Hattan-type rice with Yamada-nishiki the authors find that Yamada-nashiki has the same lined-shinpaku as Hattan No. 35 but with even fewer gaps. All of this (lined-shinpaku with low number of gaps) leads to less fragility for Yamada-nishiki than Hattan No. 35.

So, while a large shinpaku is important for sake brewing it is not enough by itself to make a rice type suitable for daiginjo.

 

P.S. Furukawa, S. is referenced in the 2ed paper 🙂

How much moisture? How dry is dry?

How much moisture? How dry is dry?

I decided to do a quick experiment to determine the amount of moisture in my soaked rice. It had been a while since I looked up how to do this and I miss remembered how much time was required. I was thinking that it required 6 hours but in fact the procedure takes 16 hours for the drying phase. This is more than twice the time I was planning. Well, I got started and weighed out two 30g samples each of Hitomebore 90% seimaibuai, Calrose 90% seimaibuai and Calrose 60% seimaibuai. Recall that the seimaibuai is percentage of rice remaining after milling the outer portion away. Having weighed the samples, I added water to one of each of the types of rice to soak for an hour. At the end of the hour, I drained and weighed the rice again and prepared it all to go into the oven at 265°F.

With 10 hours in the oven, I removed the rice and weighed each sample. While 10 hours is a little short of 16 hours I was not willing to stay up till 3AM to complete the experiment. If 10 hours is close enough I’d expect that the dry weight of the wet and dry samples of each type should be the same. This is close to what I found but not quite. The final weight of the wet sample for the 90% seimaibuai was a little lower than the dry samples. Well, at least I know that there was enough time to remove the water weight from the wet samples.

Init Dry Weight (g)Wet Weight (1 hr. soak)Final Dry Weight (10 hr. @ 256F)
Hitomebore 90% Seimaibuai

30

27

30

39

26

Calrose 90% Seimaibuai

30

27

30

39

26

Calrose 60% Seimaibuai

30

29

30

48

29

Based on this data we can see that both the 90% seimaibuai types had 3-4 grams of water weight. This works out to be about 13% of the wet basis (Init Dry Weight). This is well within the range of expectation for table rice. Rice milled to 60% seimaibuai would be expected to have a much lower moisture level after milling and until it has had time to absorb enough moisture to come back to the 10% expected level. The 60% rice used here was milled by SakeOne and shortly after bagged bye Steinbart’s in a sealed plastic bag. So, it is not given the chance to absorb much moisture after milling. This is just what we see in the data as well; only 1 gram of water weight. One gram works out to be only 3% of the wet basis.

Init Dry Weight (g)Wet Weight (1 hr. soak)Soak % increaseSoak % Water
Hitomebore 90% Seimaibuai

30

39

30%

33%

Calrose 90% Seimaibuai

30

39

30%

33%

Calrose 60% Seimaibuai

30

48

60%

40%

As discussed in “Steeping to hit the numbers,” this data shows that having a lower initial water weight results in a higher rate and amount of moisture uptake. Both samples with 13% initial water weight gain only 30% while the 3% initial water weight sample gains 60%.

A moisture content of about 38% after steaming is considered optimal for ginjo-shu koji. Assuming steaming adds 10% moisture content (this is another experiment), we would like to high 28% water weight after soaking on a wet basis. Notice that, the 90% seimaibuai rice is closer to this ideal than the 60% seimaibuai rice.

Based on this it would be a good idea to lower the steeping time some or raise the initial moisture content of the 60% rice to be more on the order of 15% before steeping. Tweaking this a little could improve your sake.

 

Shio-koji?

Shio-koji? What it is and how to make it.

Recently, there have been a few different articles and mentions of shio-koji. I had never heard of this until these articles. I came across shio-koji through a chain of retweets from @seishu and @theprovenance originating with @ChrisPellegrini Anyway, these tweets were pointing to an article by Makiko Itoh  in The Japan Times: Kōji — Japan’s vital hidden ingredient. Of course the thing that caught my eye was the use of koji. I am familiar with amazake but shio-koji with a third of the koji’s weight in salt? That seems like a lot of salt to me but most of the articles seem to imply that shio-koji used as a replacement condiment for salt would reduce salt intake.

Having read Makiko-san’s article, I thought it was interesting and that I should give it a try some time. Really was not thinking about doing this anytime soon though. Then I saw another reference and another… What is going on with this stuff. Finally @keyope put up a page (now gone) with the amounts of all three ingredients, koji, salt and water. This matched very closely with almost every other recipe I see so what the heck, I’ll give it a try.

I didn’t want to make a lot so @keyope’s recipe size seemed just about right to me; only 30g of salt, 100g of koji and 150ml of water. I combined this together this morning and stirred them up. They are sitting on the counter now.

It turns out that 150ml of water is too much for use with my fresh koji. It would probably be a better amount for use with koji like Cold Mountain’s. I guess the best advice here is to add a little, maybe 100mls worth in this case and then add more if needed.

This stuff is pretty salty tasting but we will have to wait about a week to see how it turns out with the koji enzymes transforming the basic ingredients. I’ll add and update in a week.

First “Special Ginjo” Koji-kin for homebrewers!

First “Special Ginjo” Koji-kin for homebrewers!

We have just added the Akita Konno “Special Ginjo” koji-kin to our offerings in the store. This new koji-kin has been developed at one of Japan’s leading koji-kin suppliers specifically for making Ginjo sake.

Unlike most koji-kin available for homebrewers, Akita Konno’s special ginjo koji-kin is specifically for making sake. We provide two 1 gram packets, each of which will make more than 3 lbs. That’s enough for two standard batches of sake.

The instructions provided have been reviewed by Akita Konno to insure the information given meets their high standards.

 

Ode to the rice farmer

Ode to the rice farmer, 2011 California Rice Farming

This week I thought that it would be interesting to look at the rice production in the US. This quick look will actually be narrower than the whole of the US in that I am using material exclusively from the Sacramento Valley in California. However, many of the themes will be true for the US and are in stark contrast to what we often see related to rice for sake, our primary interest.

I have been watching the youtube channel RiceNews for a couple of years now and find it to be very interesting. All of the videos here have been selected from their offerings.

While the rice farming families in the US can’t go as far back as those of Japan can, many of those in the Sacramento Valley go back to the beginning of California production.

In the following, I have pulled together views into each stage of rice growing. There was nothing on drying, husking, milling and bagging so that is a missing piece. Maybe I can fill that in some time in the future. Continue reading “Ode to the rice farmer”

New US kura, the “Texas Sake Company” grand opening on Nihonshu no hi!

New US kura, the “Texas Sake Company” grand opening on Nihonshu no hi!

Today, Nihonshu no hi or international sake day, is not only a day to celebrate sake but, beginning this year, also the opening day for a new kura, sake brewery, in the great state of Texas. Texas Sake Company becomes the 7th currently active US sake brewery.1

Using a strain of organic Texas rice that is said to have a heritage that traces its roots back to rice from a Japanese delegation that came through Texas in 1904, The Texas Sake Company will specialize in local organic ingredients. Yoed Anis, the founder and Toji of Texas Sake is truly excited about using Texas grown rice with roots that go back to Japan.

Texas Sake has actually been operating for some time while getting ready for the grand opening, October 1, 2011. They began at least as early as February to produce test batches of sake which they gave away to their followers in Texas; a nice way to build the following. Their grand opening is being held at the brewery: 5501 N Lamar Blvd, A115, Austin, Texas.

It is wonderful to see a new kura starting up; welcome Texas Sake Company.

 

  1. I have documented the other US sake brewers here.

Possibly the first ever Bodai moto made outside of Japan!

Possibly the first ever Bodai moto made outside of Japan!

I have just completed the pressing of a sake made with a bodai moto and while the story is still not complete I think this may be a good time to look at what we have so far. The bodai moto is the original method of creating a moto. As I have written before in this venue, the bodai moto was created from a sake brewing method known as bobaisen. Bodaisen was sake made using the same method used for bodai moto but there is no additions added later. For bodaisen you put all the ingredients together at the beginning and then ferment to the end with no additions. Over time it was found that adding a bit of the mash of a good brew to the beginning of a new brew helped make better sake as well as make it more reliable. As the properties of the sake improved while adding a “starter” from a good batch, this became the norm and even the first batch needed to have a starter and this push for better sake is how the method for making bodaisen became the method for making bodai moto.

Bodai moto is also called mizumoto or water moto. The name mizumoto makes a lot of sense once you begin to look at the method used and what it produces. The outcome of the first step of the method is a special water called soyashi-mizu that contains, along with the water, lactic acid that will protect the moto and the ferments made with this moto. There are also other compounds from various bugs that became active before there was enough lactic acid to kill them off. These bugs and their effect on the moto bring distinctly different contributions to sake. Similar to yamahai moto sake, bodai has its own funk.

To start a bodai moto we need to make the soyashi-mizu. Soyashi-mizu is created in the soyashi process which consists of mixing a small amount of cooked rice with raw rice and water and letting stand until the lactic acid reaches the desired strength. Now I should say that in the original process this is also key to cultivating a good yeast population. Because I will add yeast I am not really looking for this but it may also be a strong contributor to the resulting characteristics. Continue reading “Possibly the first ever Bodai moto made outside of Japan!”

New Page on Koji Making with Video

New Page on Koji Making with Video

OK, so I have finally pulled together a complete page on making koji for sake brewing along with the videos. As with the videos for brewing sake there is nothing amazing here but that may, in fact, be the amazing thing. When it comes to making koji, like brewing sake, it is all very doable.

I believe the text for the koji making page is very readable and stands on its own without the videos. However, the videos may help to solidify what is said in the text. All in all I hope you find the page useful and enlightening!

Oh, FYI, I have linked the koji making  page into the top of the Recipe page for convenience.