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 🙂

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.

Digging into US rice – where did it come from?

Digging into US rice – where did it come from?

Discussions with a friend challenged my understanding of some aspects of US rice production. I had focused on California rice for most of my earlier research and really, if the truth is to be known, discounted most of the rest of the country. My understandings were not all wrong but some generalizations where flat out incorrect and this led to other beliefs being wrong as well.

Most of the rice grown in California is medium grain while most of the rest of the country grows predominantly long grain rice. This fact led to my incorrect conclusion that most of the country grows Indica rice; NOT TRUE. As it turns out very little of the rice grown in the US is actually Indica rice. So, what is all this long grain rice that is being grown? It is tropical Japonica; sometimes known as Javanica. I prefer to use Javanica but this term is becoming less and less common. Anyway, tropical Japonica comes in both long and medium grain forms.

So, while being wrong about most states growing Indica, it is true that there is a distinct difference between the rice grown in most rice producing states and California. Most rice grown in California is Japonica while most rice grown in the other major rice producing states is tropical Japonica; a distinctly different rice. Even the medium grain rice grown in these states tends to be tropical Japonica.

Continue reading “Digging into US rice – where did it come from?”

Rice Malt, Not for Sake but still interesting

Rice Malt, Not for Sake but still interesting

While researching rice and enzymes I came across an article on how steep time and temperature influence rice malt enzyme production. Malting is a major part of most beer brewing but while sake is, by some definitions, a beer, it does not use malt; not rice malt, not any kind of malt. Instead the rice used for sake is milled to remove the outer layers of the grain, which destroys all possibility of malting.

Malting is the process of transforming a grain from a seed to a malt that contains not only the starches and proteins that where present in the seed but also enzymes that can be used to convert the starches and proteins in the malt to sugars and amino acids.

To malt seed, the seed is steeped in water and allowed to dry a little in order to awaken the seed to begin to grow. The steeping and drying may be carried out several times to fully engage the embryo’s growth but ensure the seed does not drown. Once the embryo has begun to sprout roots and a shoot, a maltster will halt the embryo’s transformation by heating or kilning the grain. This prevents the enzymes from fully distributing throughout the endosperm and converting it before it is ready to be used.

Continue reading “Rice Malt, Not for Sake but still interesting”

Steeping to hit the numbers

Steeping to hit the numbers

Picture the toji presiding with a stopwatch over kurabito as they steep rice for a batch of daiginjo; pull it out of the water. A 31 second steeping to reach the desired 29% uptake of water into the rice kernels. The precision required is just amazing, but why, why is this so time critical?

We need to back up a little and consider what we are trying to do. The goal is to have our steamed rice weigh 1.38x to 1.4x the pre-steeped rice.1 That is to have the rice take up slightly less than 40% of its weight in water by the time it has completed steaming. Steaming will add another 10% or so water uptake. Backing off to pre-steam levels gives us 1.28x to 1.3x for steeping. So how long will this take and why is it different for different grades of sake?

While there are differences between rice variety and milling rates, it turns out that one of the main contributors to the rate of water uptake during steeping relates to the moisture content the rice starts with. In fact it is this factor that is the main cause for highly polished rice to absorb water so quickly and hence the need for a stop watch.

Continue reading “Steeping to hit the numbers”

  1. These targets may vary a bit from place to place.

How much sake does a pound of rice make?

How much sake does a pound of rice make?

I recently saw a section in “The Niigata Sake Book” labeled “How Much Sake Is Made out of 1 kg (2.2 lb.) of Rice” and thought this would make a nice topic to cover. I may later do a more in depth look at this but for now we will just get a good idea of the basics.

OK, so if we start with rice, water and some microorganisms how much sake will we get?   Well, let’s start with brown rice as does “The Niigata Sake Book.”  To make sake starting with brown rice the first thing that needs to be done is to polish the rice to a level needed for the type of sake we wish to make. To get down to the edge of junmai ginjo type sake we need to polish the rice to 60% or less. So let’s say we will mill the rice down to 60% of the original brown rice. That is, if we start with 1 lb. of brown rice this will leave us with 0.6 lbs. of white rice.

Now, for this there is a key ratio that needs to be understood. While this ratio will change somewhat for individual sakes, we will simply choose a reasonable example ratio for this analysis. The ratio of water used to the weight of rice added is around 1.3x, so that is what we will use. This implies the water needed for the fermenting mash will be 0.78 lbs. = 0.6 lbs x 1.3. The fermenting mash (the Moromi) will then be 1.38 lbs. = 0.6 lbs. rice + 0.78 lbs. water.

Continue reading “How much sake does a pound of rice make?”

Amazake – it ain’t sake

Amazake – it ain’t sake

I have meant to post a little something about anazake for some time but I keep putting it off. Now that I have gotten a question about how to make it I can see that it is overdue and I should get my act together. Amazake is a rice and koji mixture that is most thought of as a drink but has other uses as well.

OK, so to make amazake you need koji and rice. You can make koji with the method discussed in the earlier post, “Making Koji for Sake.” In this case you will need to start with koji-kin. If you prefer you can skip making your own and just buy the koji. I have both koji and koji-kin in the store.

Once you have the ingredients, koji and rice, cook 3 cups of rice just as you would to eat the rice.  When cooked, thoroughly mix 1 cup koji with the now 3 cups of cooked rice. Leave this in a warm area (75F-85F is good but could be as high as 140F) for between 6 hours and 12 hours. You should stir this every couple of hours; each time tasting it. It should get sweeter and sweeter until it stabilizes. When it stops getting sweeter it is done. At this point it should be quite mush like. Put it in a sauce pan and boil it for 5 minutes but be careful not to scorch it. This denatures the enzymes and stops the transformation. Continue reading “Amazake – it ain’t 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”