The Sake of Goshu no Nikki

Alcohol may be a bit of a taboo in the modern age, but it’s always played an important role in society. Whether that be as a social lubricant in bars and taverns, a token of celebration in store openings or toasts, or a tenant of religious ceremony, and there's few better examples of a drink that encapsulates all of these than sake. Sake, or nihonshu (日本酒) as I’ll be referring to it from here on out, is the national beverage of Japan, and is made from fermenting rice into alcohol. I say nihonshu because while sake is how the beverage is referred to in the states, the Japanese word sake (酒) can actually refer to any alcohol, whereas nihonshu specifically refers to what we call sake.

Introduction

Nihonshu, much like matcha and woodblock printing, initially came from China, with the Records of the Three Kingdoms suggesting that it was first consumed in Japan in the late 3rd-century. However, the first technical recipe for nihonshu, titled Goshu no Nikki (御酒の日記), wasn’t written until much later, either being written in 1355 or 1489, depending on how you interpret the calligraphy for the date on the manuscript. This is significant because it suggests that while the Goshu no Nikki is the oldest known record of nihonshu brewing methods, the recipes outlined within it likely aren’t the same as the ones used back in the 4th and 5th centuries. This idea is supported both by the variance in complexity of the five recipes within the Goshu no Nikki, as well as the historical context surrounding the innovation of nihonshu brewing methods that occurred in the Muromachi period (1333-1573).

Evidence suggests that many of the developments that led to the methodology by which modern nihonshu is brewed were pioneered at Shōryaku-ji (正暦寺), a Buddhist temple of the Shingon Sect in Nara. The brewers at Shōryaku-ji established a number of production methods that were unheard of prior, namely the use of polished rice instead of only brown rice (諸白造り, morohaku zukuri), the use of three sequential, quantitative additions of rice, kome koji, and water to the ferment (三段仕込み, sandan jikomi), pasteurization via heat (火入れ, hiire), and most importantly the use of a starting mash (or yeast starter, as it is sometimes called) that was acidic due to the cultivation of bacteria that performed lactic acid fermentation (菩提酛づくり, bodaimoto zukuri). But to explain why these things are important to nihonshu brewing, as well as to be able to understand and break down the contents of the Goshu no Nikki, we need to first discuss the fundamentals of nihonshu brewing and the science behind it.

Notably, I say science, but as Rath notes in his discussion of Goshu no Nikki, “what is today a science was in the past a product of centuries of trial-and-error methods.” The brewers of the premodern era may not have known the microbiology behind their ferment working, but they know it worked.

Background

The main ingredients for nihonshu are as follows: rice (米, kome), kome kōji (米麴), water (水, mizu), and yeast. Biologically speaking, the process of brewing nihonshu, or any rice wine for that matter, is actually relatively similar to beer, and is outlined below.

**Figure 1. Representation of the Biological Processes that Occur in *Nihonshu* Fermentation**

In both beer and nihonshu brewing, starch from the rice or grain used is broken down into sugar, which is then consumed by yeast to create alcohol via ethanol fermentation. The two processes fundamentally differ with how the sugar is broken down. In beer-making, the enzymes that break down the starches into sugar are already present within the grain, and are activated by breaking the grain open and steeping it in hot water. With nihonshu brewing, however, since rice doesn’t naturally possess the needed enzymes an exogenous source is required, which is the mold Aspergillus oryzae (麴菌, kōji kin). Kōji kin is inoculated into steamed rice, where it grows and permeates the whole grains of rice. Once the kōji kin permeates the rice and creates a white, fluffy exterior, that is known as kome kōji (米麴), or koji rice. The koji mold contains enzymes that degrade starches into sugar. Interestingly, while in beer-making the starch is converted to sugar, and then only after fermentation of sugar is done, in nihonshu brewing, both the breakdown of starch into sugar and the fermentation of sugar into alcohol occur simultaneously in the main ferment. Because alcohol ABVs are typically determined via density readings (more specifically Specific Gravity) that change as dissolved sugar (something that is more dense than water) is converted into ethanol (something that is less dense than water), this results in the ABV of nihonshu being very hard to accurately measure without very expensive, specialized equipment, and it's an issue I address later on.

The actual process of brewing nihonshu is broke into two phases, the moto (酛), and moromi (諸味). The moto is what the west sometimes refer to as a ‘yeast starter’, and is effectively a small, scaled-down version of the main ferment where the yeast is added to make sure it is accustomed to the environment and is maximally active. This is where the aforementioned bodaimoto (菩提酛) comes in. Bodaimoto literally translates to enlightened (菩提, bodai) starter (酛, moto), and brewers named it such because this particular method of moto led to a much lower rate of spoilage and contamination of other organisms (and because this was at a Buddhist Temple so they figured that the power of Buddha was helping them brew nihonshu). The bodaimoto works by cultivating lactic acid bacteria that create lactic acid and result in the moto becoming acidic, typically slightly under a pH of 5. This is significant because these low pHs prevent most microbe growth, resulting in the reduction in spoilage premodern brewers observed.

The other phase, moromi, consists of the addition(s) of rice, koji rice, and water made to the moto. As mentioned earlier, one of the methods pioneered by Shōryaku-ji was the sequential three-stage addition of rice, koji rice, and water during the moromi phase (三段仕込, sandan jikomi), mainly done because it maximizes the activity of the koji and yeast enzymes. In theory, premodern brewers observed that this specific method of addition resulted in faster fermentation and maturation of the ferment, something that has since been confirmed by scientific analysis.

Given this background, I’ve outlined the following questions to be analyzed, and hopefully answered: (And naturally, other insights will appear along the way.)

How does the biochemistry of the pre-modern nihonshu outlined in the Goshu no Nikki differ from that of modern day nihonshu?
What can the Goshu no Nikki and the process of brewing premodern nihonshu tell us about pre-modern Japanese society and the role that nihonshu played?
How different did pre-modern nihonshu taste when compared to modern nihonshu?

Analysis of the Goshu no Nikki

**Figure 2. Translation of the *Goshu no Nikki*.** Translated by Eric Rath

With that background on the history and science of nihonshu, we can properly examine the Goshu no Nikki (I’m using a translation by Eric Rath). There’s a lot to unpack, and for the sake of brevity and simplicity, I’ll only be focusing on the recipe for ‘glossy silk’ or nerinuki nihonshu. I chose to focus on this recipe specifically because of something Rath mentioned in his discussion of the translation, that the ‘glossy silk’ nihonshu results in an end product much like modern-day nigorizake (濁り酒). This means that it can more easily be compared to modern nihonshu. Additionally, making clarified nihonshu requires at least another week of racking and cold-crashing to remove all of the particles within the liquid, something that I didn’t have time for in this reconstruction. Now personally, as an avid coffee drinker, I believe in the art of comparative tasting, and in my mind the only way this ‘glossy silk’ nigorizake can be compared to its modern counterpart is by also making a modern version that follows the steps breweries nowadays do, but with the exact same ingredients as the pre-modern version. So that’s exactly what I did.

Looking closely at the ‘glossy silk’ recipe, we get a lot of information about the methodology used. The recipe has quantified, volumetric recipes and ratios that we can follow. There’s reference to the specific method that the rice used was cooked with (steaming). It uses the bodaimoto starter method, as the rice sits for seven days without any koji rice to convert starches into sugar. There’s mention of the use of polished rice for the nihonshu as opposed to unmilled brown rice. Also there’s a whole section on pasteurization.

But in analysis of the recipe, we can also see how much is missing, and there is very clearly a strong presence of tacit knowledge, both from the details kept out of the text itself and the commentary Rath makes in his translation. The Goshu no Nikki starts off with “Sake Journal is an oral secret that must be kept completely private”. There’s almost no mention of water or amounts used. There’s no mention whatsoever of yeast or how the sugars are fermented. There’s no information on how to press the end ferment out of the lees. There’s no discussion about how polished this rice is.

This obstacle was by far the hardest challenge I faced when brewing nihonshu. Due to the secrecy surrounding these methodologies, very important details crucial of the brewing process are missing. Given this, I did my best to fill them in without copying modern practice. Importantly, however, I will not refrain from examining the scientific knowledge surrounding the nihonshu, as some things I must take from our current knowledge of nihonshu in order to achieve the end-result that pre-modern brewers achieved in the times they achieved them.

Case in point, the amount of water added to the ferment and the resulting water:rice ratio. If there’s too much water relative to rice and koji rice, then the enzymes of the koji rice and yeast will function slower than they’re supposed to due to the enzymes and the produced glucose being too dilute. However, if there’s too little water and the resulting koji enzymes, yeast enzymes, and glucose become too concentrated, then activity will slow too. This is because too high of a concentration of sugars and other substances dissolved in the ferment will result in osmotic pressures that are too high, conditions which hamper yeast cells’ intake of nutrients, slowing their activity. To maximize enzymatic activity, modern brewers use a rice:water ratio of 1:1.5-1.6, so I’ll be using a ratio of 1:1.5 for this recipe.

Regarding the use of polished rice, modern nihonshu typically uses rice that is polished down to 70% or less of its original size, with the increase of the amount of outer shell milled off generally corresponding to more delicate, floral flavors, and higher prices. But the term ‘polished rice’ can also be referring to table rice, which is milled down to ~90-93% of its original size, depending on the brand. Thus in theory, the term ‘polished rice’ can refer to any of the above. But more likely than not the ‘polished rice’ the Goshu no Nikki is referring to is akin to something like modern dinner rice. This comes down to the machinery, energy, and time required to mill rice. To mill brown rice down to dinner rice levels (~90-93%), the process takes a few hours at most, and can be done with relatively simple equipment. To mill it down to ~70% (the standard for junmai nihonshu), it takes several hours. But to mill it down to ~50% (the standard for daiginjo), it takes more than 48 hours. Milling rice down past dinner rice levels results in diminishing returns on the time invested, and requires significantly more advanced machinery. Therefore, pre-modern brewers likely used dinner rice, if not something coarser. Because of this, for both brews I used Kokuho short-grain rice.

Then, the issue of yeast. There actually isn’t a clear answer on whether the brewers added a selected yeast to their ferments or if they relied solely on wild yeast from the environment. The bodaimoto method typically isn’t thought to involve the brewer adding a yeast strain of their choice to the moto, but the answer becomes complicated when you consider the two methods of moto that evolved from bodaimoto: kimoto (生もと) and yamahai (山廃). Both kimoto and yamahai involve the use of lactobacillus to create an acidic environment within the moto, but while kimoto additionally relies on wild yeast from the environment finding its way to the brew, in yamahai brewing the brewer selects a specific strain of yeast to be added to the ferment. In addition, in the ‘glossy silk’ recipe the ferment is covered with a mat the entire duration of fermentation, vastly limiting the exposure of airborne microbes to the moto and suggesting that wild yeast couldn’t have been consistently introduced into the moto this way. However, Rath theorizes that mats used to cover previous batches of nihonshu could’ve potentially trapped some yeast cells from the former ferment, and subsequently propagated to new batches through re-use of the mats. In short, the answer is unclear, and I ultimately chose to introduce yeast to the pre-modern ferment because 1) cultivating wild yeast takes weeks, and 2) using the same yeast as the modern ferment helps us better isolate the effects of the lactic acid bacteria and difference in methodology in the tastes of the two brews. That isn’t to say that the difference in yeast wouldn’t make a difference in taste, in fact I believe the contrary, but that is a test for another day.

Pre-Modern Nihonshu Methodology

Finally, we have a reconstructed recipe for ‘glossy silk’ nihonshu:

Measure out 10 parts rice and wash it, steaming 1 part of it and allowing it to cool

Put the 9 parts uncooked rice in 10 parts water in a food-safe container, then put the 1-part cooked rice in a bamboo basket and place it in the center of the uncooked rice, covering the basket with a mat

After 7 days, remove the mold at the top of the water, remove the cooked rice in the basket and set it aside

Steam the remaining 9 parts uncooked rice and allow it to cool
Take the water from the bodaimoto (now called soyashi mizu, or blessed water) and boil it down to ~80% volume
Take 1 part of this soyashi mizu and pour it on top of the freshly steamed rice
Let that mixture sit for an hour, then stir it, and let cool overnight

The next day, combine the previous day’s mixture (the 9 parts rice), the remainder of the soyashi mizu, an additional 6 parts of (cooked) rice, 6 parts of koji rice, and 13 parts of water, all into a fermentation container

If adding yeast, that’s also done here
Stir this twice per day, and if it stops bubbling
Cover with a mat and allow it to rest for 7 days

Add the initial 1 part cooked rice from the bodaimoto that has been set aside, another 1 part koji rice, and 1 part water into the ferment.
- Wait 20 days
Press the nigorizake

Before I discuss the actual reconstruction, a few notes on the reconstructed recipe:

In total, the recipe requires 7 parts of koji rice, 16 parts of rice, and 24 parts water (using the aforementioned 1:1.5 ratio).
The distribution of water across the additions made were done based on other recipes within Goshu no Nikki, notably from the ‘goshu’ recipe, where the moto involves using equal parts of rice and water to start, but notably not having that same equal ratio in the moromi addition
Whenever I ‘set something aside’, I stored it in the fridge using plastic wrap to seal it, covering that with aluminum foil to make sure the plastic wrap doesn’t slip, and additionally prevent excess exposure to light
Using rough estimates of obtaining ~1 gallon (~3.78 liters) of end-product nigorizake leads me to 1 part being about 147 mL
All the water used for both this and the modern equivalent was dechlorinated tap water, where it was left out for >24hrs covered with a cheesecloth so that the chlorine in solution had time to precipitate from solution into the air, but distilled water works too

Pre-Modern Nihonshu Reconstruction

To begin the reconstruction, I washed 10 parts of rice, and 1 part of rice was steamed using a bamboo steamer, then cooled. Since I don’t have a bamboo basket to serve as a semi-permeable container of sorts, I opted to use a cheesecloth to wrap the cooked portion of rice and placed it in the middle of the bodaimoto, and waited. For the food-safe containers, I used the cheapest option available to me, mylar bags. I placed them inside non-food-safe buckets to support them. Since I don’t have mats to seal my ferments, I used another cheesecloth as my ‘airlock’ of sorts, as many homebrewers use cheesecloths as pseudo-airlocks to great effect. However, I waited a week and nothing grew. I grew puzzled, and did some digging online, where I found Fred Eckhardt’s website, Homebrewsake, and discovered that he actually documented his own bodaimoto nihonshu, and he left his bodaimoto open to the air. I then left it open to the air for a week, and sure enough there was plenty growing in the moto. There was mold on the surface of the water and a pinkish-red hue to the water below. To ensure that the right bacteria were growing, I purchased some pH strips on Amazon, and sure enough after a week of open-air exposure the bodaimoto reached a pH of about 5.

During this time I also grew koji rice. Koji rice is itself a very simple thing to make, as the packet of spores has instructions on the back that I followed: steam rice and then let it cool, add 2g of spores for every 400g of rice, then stir and mix until the spores are all throughout the rice, then let it sit at room temperature covered for two days in order to mature.

After 7 days, I quenched the bodaimoto, separating the cooked rice, the uncooked rice, and the soyashi mizu. The soyashi mizu was extremely cloudy and almost milky in appearance, as a result of the microorganisms that grew during the week. The (1 part) cooked rice went into my fridge, then the uncooked rice was steamed, and the soyashi mizu was reduced. As per the recipe, 1 part of the soyashi mizu was added to the cooling rice, and then both were also placed in my fridge to cool overnight.

The following morning, I started the moromi, adding the (9 parts) steamed rice from the day prior, the soyashi mizu, 6 parts of rice steamed that day, 6 parts of koji rice, 13 parts of water, and yeast. After this point, there was near-constant bubbling, to the point that it was audible even when the container was sitting still. I intended to use the ‘sake yeast #9’ strain from Wyeast Labs, but USPS delayed the package by 5 days, and delivered the yeast entirely dead. Because of the extended period of time fermentation requires, I had to pivot on a very short time-scale, and ended up using champagne yeast (specifically EC-1118) instead, as I read several accounts online who mentioned that they had success with the strain.

This was another obstacle I encountered. As far as I’m aware, in the states sake yeast is only sold in liquid form, which is a pain in the butt to obtain. Shipping it in warmer months is basically out of the question and most brew shops recommend against it. And not many stores keep it in stock since it’s relatively rare for someone to brew nihonshu at home. I actually encountered a very unique issue, however. I called Missouri Malt & Mill, the closest home brew shop (and the only one reasonably close that had the yeast in stock), only to find that someone would always buy out the store’s entire stock of sake yeast to brew mead. Great. Champagne yeast it is.

At this point I placed the ferment under ‘airlock’ with a cheesecloth and waited 7 days, stirring twice a day. Then after those 7 days I added back the initial steamed rice, another part of koji rice, and another part of water. From there, I waited.

Modern Nihonshu Methodology and “Reconstruction”

To make the modern nihonshu, I followed a recipe made by Fred Eckhardt that makes ~2 gallons, which itself is based on the Japan Sake and Shochu Makers Association’s “A Comprehensive Guide to Japanese Sake”. It explains a lot of the customs behind modern nihonshu brewing, and is a great read whether you plan on brewing some or not. You can find it on Homebrewsake.com (https://homebrewsake.com/recipe/). While pre-modern nihonshu uses a bodaimoto or bodaimoto-derivative, most modern breweries instead use a process called sokujo moto (速醸), or fast brewing, where the process of cultivating lactic acid bacteria is shortcutted by adding lactic acid directly to the moto.

For the sake of brevity, I’m going to very briefly summarize the brewing process I followed. Sometime in the future when I have more time I might write in more depth about the process, but it isn’t necessary for the sake of this essay. To the moto, I added rice, koji rice, water, EC-1118 yeast, yeast nutrient, and lactic acid, as per instructions. The moto (referred to as shubo in the recipe, the two terms are interchangeable) then sits for 7 days, stirred every 12 hours. Like with the pre-modern ferment, I’m using a cheesecloth as a pseudo-airlock to prevent spoilage. After, the moromi additions were done over four days as per sandan jikomi. In each of the three additions, a proportional amount of rice, koji rice, and water were added to the moromi, in the amounts shown above.

Much like the pre-modern ferment, once the moromi additions were made, the ferment would aggressively bubble, and it was very audible. In fact, the day of rest in between the first and second additions is called the ‘odori ferment’ (translates to dance ferment) for this very reason because of how active the koji and yeast become during this time. Once these additions were made, I waited, stirring every 12 hours or so.

A Brief Discussion of Alcohol By Volume

As mentioned previously, determining nihonshu ABV at home isn’t super easy, and it certainly isn’t accurate. However, we can make estimates. In his recipe, Eckhardt writes how at endpoint of fermentation, nihonshu brewed with dinner rice can achieve about 20% ABV, and the presence of that alcohol content will be accompanied by a specific gravity (specific gravity is just the density of a liquid relative to water) reading below 1.000, which is exactly what I achieved with my modern nihonshu ferment around 16 days after the start of the moromi. Measuring the modern ferment’s specific gravity with a hydrometer (a tool specially developed to determine specific gravity of liquids), I achieved a reading of 0.992, well below 1.000 and indicative that I had reached ~20% ABV.

As for the pre-modern ferment, measuring the specific gravity wasn’t necessary for the purposes of determining an endpoint of fermentation, as the recipe specifies waiting 20 days after the final addition. However, when I bottled, I measured it to get a rough estimate of ABV, and the specific gravity was 0.998, suggesting it either reached ~20% or got really close.

Pressing, Finishing, Bottling, and Pasteurizing

While there are instructions on how pasteurization of the ‘glossy silk’ within the Goshu no Nikki, from bottling onwards I used modern protocols and methods for both ferments for safety reasons. Both to ensure that nothing bad grows within my nihonshu, as well as to ensure there aren’t any enzymes still active that result in a pressure buildup and a glass bottle shattering in my kitchen. I also ensured that I didn’t touch any of the nihonshu directly, and wore lab-grade nitrile gloves during the entire pressing process.

To properly sanitize all my equipment, I first washed it all with dish soap thoroughly, being sure to rinse away all suds until I couldn’t smell any dish soap. Then, I used Star-San, an acid-based no-rinse sanitizer that kills nearly every microbe it touches, but doesn’t affect the flavor or appearance of what goes in next in the slightest. Among bartenders and brewers, Star-San and other similar products are the gold standard of sanitization.

Once all my gear was clean, I began pressing the nihonshu. To clarify, I did this whole process twice, once for the modern and once for the pre-modern. While I have cheesecloths, the pores of cheesecloths are too fine for nigorizake, so I used a kitchen strainer instead. Since I was doing this alone and had gloves on the entire time, I unfortunately don’t have any photos of me physically pressing the lees to extract all of the liquid. Once all of the liquid was separated from the lees (sometimes called sake kasu), I then bottled the nihonshu into 1-liter swing-top bottles from ikea. As far as I can tell, the rate of $3 per liter bottle is unrivaled, as even buying in bulk doesn’t result in that good of a rate.

Nowadays, it’s not uncommon for nihonshu to be adjusted with sugar after fermentation to increase the sweetness of the end-product, so I sweetened the modern ferment to taste, and settled on 28g sugar / liter nihonshu. Furthermore, most modern brewers will dilute their ferment down to 15-16% ABV. Full-strength nihonshu, which is the raw end-product of fermentation, is called genshu (原酒), but because it’s generally quite strong-tasting, brewers water it down a bit for taste. Going off of Eckhardt’s recipe, I added 1180 mL to the ferment to water it down a bit. (Doing the math, that’s closer to 18% ABV than the 15%-16% I thought it was in class). Interestingly, pre-modern nihonshu generally wasn’t diluted at all, and was typically served as genshu, so I didn’t adjust the pre-modern ferment at all.

Finally, once the nihonshu was bottled and adjusted, I pasteurized them. I placed each bottle into a pot of boiling water, and used a thermometer to ensure that every single bottle met the pasteurization standards set out by the FDA, 161 degrees Fahrenheit for 15 seconds. Most modern nihonshu is pasteurized via ‘vat pasteurization’, where it’s held at 145 degrees Fahrenheit for 30 minutes, but since I don’t have a means of reliably holding the exact same temperature for 30 minutes I chose the former. Once everything was pasteurized and cooled down, that’s nihonshu! In total, the modern recipe yielded me 10.5 liters, which is much higher than the expected 7.5. However, this disparity is likely due to the finished product being nigorizake, as the looser filtration means that more rice solids remain in the final product.

Comparative Tasting

When examining the two drinks side by side, the first thing you notice is the color difference. The modern ferment (which I’ll be calling the Heiwa from here on out) appears lighter in color, whereas the pre-modern ferment (which I’ll be calling the Ronin) appears darker and thicker. Both have a yellow tint that normal nigorizake doesn’t, and I suspect that is due to the champagne yeast and its fermentation byproducts. The Heiwa nigori gives off a slight note of citrus, nothing too strong but definitely noticeable. The Ronin nigori, however, has a bolder nose to it, and almost smells nutty. The Heiwa nigori goes down super easy, it’s really smooth, sweet, juicy, and light, with a citrusy aftertaste reminiscent of, well, champagne. It’s a great sipper, and why I’m labeling it ‘Heiwa’, which translates to peace. As for the Ronin nigori, it’s much bolder and has a richer texture, with much more mouthfeel. There's a definite nuttiness and earthiness to the flavor, and it feels much stronger. There’s also a citrusy, acidic note to the Ronin, but it’s almost suffocated by everything around it. It’s very hard to taste the alcohol in the Heiwa nigori, but it’s quite noticeable in the Ronin. Almost everyone who’s tasted it so far has enjoyed the Heiwa nigori, but the Ronin has been much more controversial. The added acidic note in both the Heiwa and Ronin are likely due to the use of champagne yeast, but much of the other differences are likely a result of the difference in moto and subsequent chemistry occurring.

Discussion and Takeaways

One of the biggest takeaways of this project is just how advanced nihonshu methods were back in the Muromachi period. The Ronin nigori tasted unlike any other nigori I’ve had, but it still tastes and smells undoubtedly of nihonshu. It also bore significant resemblance to the Heiwa. Above I picked apart a lot of the differences between the two, but both still achieved proper fermentation, reached proper ABVs, and tasted delicious (at least in my opinion). Looking at it from a biochemical standpoint, there’s very clearly differences in the chemical compositions of the moto between the two, as the nutty, earthy flavor of the Ronin was nowhere within the Heiwa. Looking at the specific gravities of the two ferments and how long it took to achieve them additionally confirms the effectiveness of the sandan jikomi (three-stage addition) in increasing enzymatic efficiency, as the Heiwa ferment achieved a specific gravity value of under 1.000 by day 16, whereas it took the Ronin ferment 20 days.

As for the tacit knowledge implicitly (and explicitly) scrubbed from texts, it very clearly shows that while nihonshu certainly had religious significance during the Muromachi period, there was significant commercial gain and prestige to be had by gatekeeping this information. Interestingly, this manifests in the methodology too. During the bodaimoto brewing process, leaving the bodaimoto covered resulted in no bacterial or microbial growths of any kind. This is because the bodaimoto method described in the Goshu no Nikki were only able to be made at Shōryaku-ji specifically. The water at Shōryaku-ji has been found to contain the lactic acid bacteria needed for bodaimoto formation, which is why only at that exact temple does the method described work. The brewers and writers of Goshu no Nikki likely understood this and intentionally described the bodaimoto in this manner so that it couldn’t be replicated outside of their control. And this still holds true today. Modern breweries that use kimoto (生もと) or yamahai (山廃) methods will usually leave the moto open to the air. And in Fred Eckhardt’s bodaimoto too, he left it open to the air.

As a whole, this project has given me a new appreciation for alcohol, for nihonshu, and the brewers who undertook the job. I was expecting the recipe to be much more crude and more basic, and perhaps some other ones in the Goshu no Nikki might be, but the ‘glossy silk’ recipe is clearly very refined and tested, and resulted in a very drinkable alcohol (if a bit controversial on today’s palettes). It’s quite impressive to me just how similar the fundamental ideas behind nihonshu brewing today are to that of the Muromachi period, and it’s a testament to the trial and error, the tacit knowledge, and the scientific thinking that went into it.

A Short Note on Fred Eckhardt

His name has come up a few times in this essay, and not without good reason. Fred Eckhardt was an American homebrewing advocate and writer, known both for his journalism in beer and sake (I’ll stop calling it nihonshu as this isn’t a technical discussion anymore). He was pretty famous among American sake circles back in the day, and published a sake newsletter several times a year. His impact on the field is significant. But crucially, he authored the website Homebrewsake, the website that ultimately led me to brewing sake and writing this essay. Through the last month and a half, his website has guided me through this long, arduous process, and I wanted to dedicate this project to him. He passed back in 2015, so I unfortunately will never get to meet him, but his voice was very clear in his recipe, and it has felt almost as if he guided me through this project personally. Even from the grave, he’s still doing what he loves best. Without his work I genuinely wouldn’t have known where to start, and now I’m a homebrewer, so I just wanted to express my gratitude towards his writings.

Works Cited

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“Bodaimoto.” BrewSake.Org, https://www.brewsake.org/advanced/bodaimoto-history. Accessed 1 May 2025.

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“Moromi (Mash) for Sake | 諸味.” BrewSake.Org, https://www.brewsake.org/moromi-mash. Accessed 1 May 2025.

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Rath, Eric C. “Sake Journal(Goshu No Nikki).” Gastronomica, vol. 21, no. 4, Nov. 2021, pp. 42–50. DOI.org (Crossref), https://doi.org/10.1525/gfc.2021.21.4.42.

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