Henpei and Genkei: Rice polishing for a new era in Ginjo brewing.
Updated: Apr 28
The so-called "rice polishing war" is finally over. What began over two decades ago and led to the creation of some genuinely superb sake, not to mention an entirely new sub-category of the dai-ginjo classification, later descended into what at times felt more like a juvenile game of one-upmanship. And as the ratio of polishing began to reach single digits, it quickly became clear that the purpose of these ultra-premium brews was more about the bragging rights and publicity than actually trying to improve on the quality of the all important liquid inside the bottle. But a contest based purely on reaching the lowest number can only last for so long, and inevitably it all came to an abrupt and anticlimactic end earlier this year with the release of a sake claiming to have a polishing ratio of 0%.
Of course the actual polishing percentage was slightly higher than that, at 0.8%, but due to a technicality in the rules that allows polishing percentages to be rounded down at any decimal point, the producers were able to claim the latest bragging rights in having reached this definitive milestone. However, after all of the hype and fanfare that had accompanied the release of Tatenokawa's 1% sake the previous year, this latest offering felt more like a mere gimmick rather than any great feat of brewing. Even before its release, people were already starting to wise up to the headline grabbing nature of these products, and many called into question the supposed gains to cost ratio that came from polishing away so much of the original grain.
At the time, I also challenged the notion that "less was more" when taken to these extremes, and argued that the legacy of these super-premium dai-ginjos was merely a general misunderstanding as to what constitutes quality in sake. Those of you familiar with the 1984 mockumentary This is Spinal Tap may remember the now legendary scene with Nigel explaining how their guitar amps were" one louder" than regular amps because they went up to eleven rather than ten. Well, to me at least, that is how this argument sounded. It lacked any nuance, and always seemed to be devoid of any proper explanation as to how polishing to these extremes actually improves quality. The focus was often just on how the latest release was ''one lower'' than the previous, accompanied by bombastic statements about how they had achieved the pinnacle of brewing.
Some argued though that the lack of any real justification was besides the point, and that these exuberantly priced brews would no doubt help raise the profile of sake overseas, which in turn would help struggling brewers to raise the price of their products. However, the idea that in order to raise prices would first involve drastically increasing their expenses buying rice felt a bit like suggesting using petrol to put out a fire. In reality, the notion that "more polishing equals better sake" most likely only served to put even more pressure on breweries to try and keep up with the already extortionate costs involved in sake brewing. Regardless, if this was genuinely supposed to have been an effective strategy in raising sake's profile, it instead ensured that the whole trend of ultra-polishing went out with a whimper rather than a bang, and left many educators around the world with yet another misconception about sake to deal with.
However, as we enter into a new decade, some very exciting developments regarding rice polishing are afoot within the industry, and the early signs suggest that these could be genuine game changers for ginjo brewing. Unlike just indiscriminately polishing away greater proportions of the rice, these latest developments instead represent a significant step forward in the process by actually maximising the efficiency from each grain used. Furthermore, they have the potential to not only improve the quality of the sake we drink, but can also demonstrate tangible reductions in the expenses involved in sake brewing. So without further ado, let me introduce both genkei and henpei polishing, and the company behind the revolutionary technology that is making them both economically feasible.
Satake and the rise of ginjo-shu
Hiroshima prefecture is said to be the birthplace of modern ginjo sake. Their claim to this coveted title comes courtesy of the legendary brewer Miura Senzaburo (1847-1908) who developed a method of brewing premium sake using the prefecture's difficult soft water. At one stage simply deemed unfit for sake production, this method compensated for the lack of minerals in much of Hiroshima's water by placing more importance on the quality of the koji being used and fermenting for longer periods at cooler temperatures. Fortunately for Senzaburo, at around the same time that he was carrying out his many experiments of trial and error, one Riichi Satake was also busy at work in Saijo, Higashihiroshima, developing Japan's first power driven rice mill. This state-of-the-art technology would later compliment the new style of brewing that Senzaburo devised.
Up until this point, the task of polishing rice had been a formidable one. Both laborious and time consuming, attaining the levels required for making what we now classify as ginjo-shu was simply not feasible. However, with the release of Satake's revolutionary milling machine, brewers in Hiroshima were for the first time able to polish down to the previously unfeasible ratios that now legally define this classification. Inevitably, the awards soon followed, and in 1907 the brand Ryusei from Fuji Shuzo in Takehara received the 1st prize at the inaugural National Sake Contest. This afforded Hiroshima national acclaim and firmly established their place as one of the top sake producing regions in Japan. As a result of this breakthrough, Satake would soon go on to become Japan's leading manufacturer of rice polishing machinery, and to this day enjoys a 70% share of the world market.
Fast forward to 2020 and Satake are once again at the forefront of introducing groundbreaking new technology in rice polishing in order to advance the production of ginjo brewing. Whereas before the focus of development was on the size of the grain, this time they have concentrated on the actual shape after polishing. Although milling to the extremes of single digit ratios almost certainly leaves only the starchy white centre of the grain, known as the shinpaku, it is also a highly inefficient operation to perform, taking weeks and sometimes months of continuous polishing to achieve. Furthermore, the jury is still very much out as to where exactly the point of diminishing returns begins and ends. Does rice that's been polished to say a 3% ratio actually have any more purity than one with say a 6% ratio?
Many people working within the industry think that the answer is no, and indeed some are even adamant that rice polishing becomes a fruitless exercise after just the 35% mark. Of course the actual figure cannot be so arbitrarily decided upon, and it most likely depends on the strain of rice being used. But at some point, surely, all that is going to be left is the starchy centre. Therefore, it seems the more pertinent challenge would be instead to try and figure out how to get as much of the unwanted outer layer removed in the most efficient way possible. And with their new state-of-the-art machinery that utilises bespoke grindstones, that is precisely what Satake have achieved.
Henpei (Flat) Polishing
Those of you already familiar with henpei, or "flat polishing", will know that these days it is actually nothing new, and was originally conceived in order to more efficiently remove the unwanted fats and proteins found in the outer layer of the rice, whilst at the same time leaving as much of the starchy centre portion intact. The crux of the problem with the conventional method is that it can only polish grains into a spherical shape. However, the shinpaku often has the same oval shape as rice does in its original unmilled form. Therefore, by polishing away evenly from both the length and the breadth, much of the unwanted outer layer still remains, even when done to dai-ginjo qualifying levels. The henpei method on the other hand polishes with a bias towards the breadth of the grain, resulting in a flat oval shape that more closely matches that of the shinpaku.
What this translates to in terms of benefit to the final product is that it should result in a much "cleaner" sake that is comparatively lower in amino acids. For example, henpei rice with a polishing ratio of 60% is said to have the equivalent protein content of rice polished to 40% by the conventional method. However, up until now, henpei has only been achievable by making power intensive alterations to conventional milling equipment. Broadly speaking, this involves substantially reducing the speed at which the machine mills, which of course drastically increases the time it takes over conventional polishing, thus making an already expensive process even more costly. As a result, very few breweries currently use this method, and the limited sake produced from it are very much considered a niche segment of the market.
The machinery that Satake has created differs in that it deals directly with this energy usage issue by utilising a new grindstone that can flat polish without making any of the costly adjustments to the running of the machinery. However, there remains one problem in that it doesn't account for the numerous characteristics specific to each of the different strains of rice. As the form of the shinpaku varies in size and shape between these various different strains, there are some that don't match the flat oval shape it produces. For example, whereas the most widely used brewer's rice, Yamada-Nishiki, has a linear shaped shinpaku, the rarer Omachi has a more rounded one. Therefore, although much more effective than standard spherical polishing, henpei is unfortunately not quite the one size fits all solution to better polishing, and in certain circumstances could also even be removing some of the all important shinpaku. This is of course no fault of the machine itself, rather a fundamental characteristic of henpei polishing in general.
Genkei (Original Form) Polishing
In trying to solve the aforementioned issue, Satake has come up with an altogether new and revolutionary method known as genkei. By this method, the rice is actually polished in a way that maintains its original shape, ensuring the final grains have been evenly polished on all sides. Indeed, the name comprises of the Japanese kanji characters for original (gen, 原) and shape, style or form (kei, 形). Therefore, genkei can be translated into English as either "Original Shape" or "Original Form". I am choosing to go with the latter, as when you hold the grains in your hand you really get the sense that they have been polished in the same mould as their original form. It is as if the machinery is able to trace around the outline of the rice kernel, and you can actually see the affect it has on making the shinpaku more prominent from the opaque kernels that glisten slightly once steamed.
Whereas sake that has been made using Satake polished henpei was only first trialed last year at Imada Shuzo in Akitsu, Hiroshima, and again this year in an all new product series, that made from genkei has now reached the open market here in Japan. What this new technology means for brewers is that even rice with rounded shinpaku, for example many of the heirloom strains like Omachi and Hattan-So, can now also be polished by this more efficient method. This increases the potential for this technology even further, and Satake anticipate orders for their new machinery from not only local breweries, but those out with Hiroshima prefecture as well. With more and more regions in Japan either reviving once forgotten heirloom strains, or creating altogether new ones, the timing of this technology appears to have come at a fortuitous time in an industry that is fast becoming increasingly more experimental with rice varietals, not to mention seeing an increase in the all important consumers who seek them out.
Pros and Cons
As tempting as it would be to just finish here and start the new decade on a completely positive note, it would be remiss of me not to mention some of the finer pros and cons to both of these new methods. In brief, the good news is that the former very much outweigh the latter, yet there are still some fundamental downsides to exposing so much of the soft shinpaku before brewing. Furthermore, these points specifically relate to key stages in the brewing process, and can make the already complex process of sake brewing all the more challenging. These are especially true in the case of henpei, and are already well known to the handful of brewers who have been pioneering this technique for many years now.
First and foremost is the tendency of these very delicate rice kernels to crack during washing and soaking. I have covered this crucial stage of the brewing process in the past, so I won't go over the process again in any detail here. However, the more of the outer layer you remove, which is harder in comparison to the shinpaku, the quicker the rice will absorb water. This makes them both more susceptible to cracking or splitting, and also increases the risk that they will take on too much water before being steamed the following day. The small flipside to this is that due to the lower polishing rate, they tend to have less of the rice bran remaining (nuka) that needs to be washed off before being steamed. This means that although the risk of over absorption is higher, the rice requires less time to actually wash. Not really a game changer in terms of costs, but a welcome conciliation for brewers nonetheless.
Of much more importance to those keen to reduce costs is the significant reduction in the time it takes to polish the rice, not to mention the reduction in the actual volume needed in the first place. Indeed, the majority of the benefits to both henpei and genkei stem specifically from the fact that they don't require heavy polishing in order to achieve a low percentage of protein in the finished rice. For example, during testing, henpei rice polished for just over twelve hours to 60% achieved a protein content of just 3.56%. The same rice polished conventionally for over thirty hours, to the dai-ginjo qualifying ratio of 40%, only managed a figure of 3.83%. As I alluded to before, the cost of both the rice and the electricity required to run the machinery needed to polish it is formidable to say the least. That such a low protein content can be achieved in such a relatively short period of time marks a significant step forward in lowering the costs involved in sake brewing, and also further highlights the scale of inefficiency in ultra-polishing by the conventional method.
Indeed, efficiency is perhaps the single most important factor in any comparison with conventional polishing, and it permeates into the brewing processes long after the rice has been milled. So often, the quality of sake is determined by the ability of the rice to behave as it should during brewing. Specifically, this relates to its predictability to "melt" or dissolve in the main mash. Whether a particular strain of rice's tendency to be fast melting or slow is deemed as a positive or negative really comes down to a matter of style and preference in the sake. However, what's important to know is that it does greatly affect the final outcome of the finished product. In the case of henpei and genkei the early indications are that they will be of the easy melting variety, yet despite this the low protein content means that this doesn't necessarily lead to more "off flavours" in the final sake. They also don't produce a particularly high percentage of lees, or kasu, meaning the crucial yield of actual sake should be higher than that made from conventionally polished rice.
However, in truth, much of the previously mentioned reductions in cost are currently being offset by the comparatively higher fees that Satake charge for their in-house polishing. These are not punitive, but must still be factored into any discussion on overall expenses. Furthermore, those that wish to invest in the technology themselves will also have an initial outlay to consider, albeit Satake have made it that existing machinery can be updated rather than needing to be replaced outright. An increase in polishing costs are to be expected though, with the amount of research and development that must have went into bringing this technology to the market naturally coming at a cost. Of course, if that required for henpei polishing also becomes as readily available as genkei is, breweries will also need to decide which of the two differing styles of polishing is best suited to their own individual needs. The fact that they have to make a choice between one or the other, might yet prove to be one of the limitations to the new technology though.
In summary, although we are very much in the early stages of what is known about these two methods, it would be a safe assumption to say that the henpei method is better suited to rice with a linear shaped shinpaku, such as Yamada-Nishiki, whereas those that have a more rounded shaped one would be better suited to genkei. Therefore, the decision as to which of the two represents the best solution for each brewery will most likely be dependent on which types of rice they each want to concentrate on using. Although both methods have their own individual pros and cons, what is important for now is that a step change has occurred in the rice polishing game, and that Satake may just have opened the door to a new exciting era in ginjo sake brewing.
Opening a new chapter: The end of the current classification system?
In closing, I just want to lastly open up a debate as to some of the possible ramifications that henpei and genkei could have, on not just the production side of sake brewing, but that of the consumer experience as well. Specifically, what I am alluding to, or perhaps better to say who I am alluding to, are the small but growing band of consumers and producers alike that think it's time to entirely rethink the classification system currently in place. Famous brands such as Senkin already omit the industry standard tokuteimeishoshu classification from their labelling on the grounds that they believe it creates preconceptions with customers and that it distracts them from focussing on the true characteristics of the sake.
In my own humble opinion, they have a point, as the current system is of course primarily focused on dividing up the classes by simply the polishing percentage. As we now know from the data available on henpei and genkei, this percentage becomes far less relevant when you consider how low the protein content is at a comparatively higher ratio. Keeping that in mind: Does the term dai-ginjo really have the same meaning in a world where we know that the rice used for say a ginjo could actually have less of the unwanted proteins as those from the supposedly highest classification? Perhaps doing away with the system altogether could actually make sake more easy to understand for consumers? Or perhaps it would have a negative effect, and instead leave people who once relied on this admittedly flawed strategy for choosing sake even more confused...
These are all valid and pertinent questions, however, personally speaking, I am in two minds as to whether or not abolishing the current system altogether would be a good or bad thing. On one hand, I feel that the tokuteimeishoshu system puts far too much emphasis on rice polishing as the metric for deciding the quality of sake. As a result, the dai-ginjo category is often misunderstood, and regarded as being of the highest quality. As such, it is given much more of the limelight than it perhaps deserves. Indeed, I have stated on many occasions, and I am certainly not alone with this opinion, that in order to increase the popularity of sake outside of Japan it needs to concentrate more on the supposedly lower classifications like junmai or even honjozo. Furthermore, the crossover that exists nowadays between the various classifications greatly blurs the lines that separate them, and further detracts from any significance they have. Maybe breaking down the barriers altogether will level the playing field somewhat, and instead put more focus on the various other styles of sake...
However, I do admittedly quite like the fact that at least some form of classification system is currently in place for sake, if only to give the slightest of clues as to the profile of a particular sake when buying blind. With the plethora of interesting styles and varieties currently available to the modern consumer, this can often be meaningless, but it does offer at least some guidance, specifically when considering the price. However, this last factor would ironically also lose most of its meaning in the current classification system, with more efficient polishing surely replacing lower polishing ratios as the highest standard. Regardless, as we enter into a new exciting decade for sake, one filled with so much potential, the efforts made by Satake with henpei and genkei represent real positive change for the industry, and might just be leading us into an exciting new era that entirely alters our perceptions of quality in sake.