Rare Blog of a Novice Brewer

米麹

Rare Blog of a Novice Brewer

What is Koji Rice? A Sake Brewery Explains the Science and Tradition of "God of Fermentation"

on Apr 22 2026
Introduction: "Rice Koji" is the Foundation of Japanese Food Culture Sake, miso, soy sauce, mirin, shio-koji, amazake – none of these would exist without "rice koji." Rice koji is the unsung hero that supports Japan's food culture, a nation of fermented foods. As a sake brewery, we prepare a large amount of rice koji every year. Koji-making is not merely a manufacturing process; it's a dialogue with microorganisms called koji mold, and the very essence of craftsmanship passed down through generations. It is said that the process of koji making is where humans assist koji mold to create a comfortable environment for it to grow, as the seed koji attaches to the surface of steamed rice, extending its hyphae towards the internal moisture and proliferating on the surface. The Difference Between 麹 and 糀 Both characters represent koji mold and are often used interchangeably depending on the context. ・糀 is a Japanese-created kanji character, derived from the appearance of koji mold blooming like a "flower" on steamed rice. It often specifically refers to "rice koji" used in making miso and soy sauce. ・麹 is a kanji character introduced from China, often representing koji from all grains, and is primarily used in sake brewing. What is Rice Koji? Definition and Basic Knowledge Koji Mold "Aspergillus oryzae" Rice koji refers to steamed rice on which koji mold (Aspergillus oryzae) has been propagated. Koji mold is a type of fungus, but it is not only harmless to humans but also known as a beneficial microorganism essential for food fermentation and brewing. It is also a microorganism indigenous to Japan, and on October 12, 2006, it was recognized as Japan's "national fungus" by the Brewing Society of Japan. From an academic perspective, the genome of Aspergillus oryzae was sequenced in 2005 (by the National Institute of Advanced Industrial Science and Technology), and it was found to possess approximately 12,000 protein-coding genes. Compared to its close relative, A. flavus, koji mold has genes that produce toxic aflatoxins silenced (inactivated), confirming its high safety at the genetic level (Machida et al., 2005, Nature). In other words, koji mold is "a safe and excellent microorganism that Japanese people have selected and cultivated over a long history," and it does not naturally exist in environments outside of Japan. The "Power of Enzymes" Created by Rice Koji - The Most Important Function for Breweries For sake breweries, the greatest value of rice koji lies in its being a treasure trove of enzymes. As koji mold extends its hyphae, it secretes a wide variety of hydrolytic enzymes. Amylase = Converts starch into sugar. Amylase is an enzyme that breaks down starch (polysaccharides) into glucose and maltose. In sake brewing, this reaction enables a unique fermentation process called "multiple parallel fermentation." Beer undergoes sequential fermentation, where barley starch is saccharified before fermentation. Wine is made by fermenting grapes, which are naturally rich in sugar. In sake, the saccharification of rice starch by koji and the alcoholic fermentation by yeast proceed simultaneously. This multiple parallel fermentation is one of the reasons why sake achieves a high alcohol concentration of nearly 20 degrees while possessing complex and delicate flavors. Protease = Converts protein into amino acids Protease is an enzyme that breaks down proteins into amino acids. Amino acids such as glutamic acid, which are at the heart of sake's "umami," are produced by the action of this protease. Sake breweries often use the term "koji no chikara" (power of koji), which precisely refers to the strength of these enzymatic activities. If the koji's power is too strong, the sake becomes too sweet; if it's too weak, fermentation doesn't proceed. The koji master discerns this delicate balance through decades of experience and intuition. Lipase, Cellulase, etc. Koji mold also produces various other enzymes such as lipase, which breaks down lipids, and cellulase, which breaks down cellulose. These act in combination to create the diverse flavors and nutritional value of fermented foods. Koji Making Process: The Craft of the Sake Brewery Koji Production Process ① Selection and Polishing of Raw Rice Good koji starts with good rice. Sake-brewing suitable rice varieties like Yamadanishiki and Gohyakumangoku have a shinpaku (white core), a central starchy part, which makes it easy for koji mold to propagate. Since the polishing ratio also affects the quality of the finished koji, this step is extremely important. ② Washing, Soaking, and Steaming The polished rice is washed, soaked in water for an appropriate time, and then steamed in a steamer (koshiki). The ideal steamed rice is "gaikou nainan" (hard on the outside, soft on the inside). This allows the koji mold to easily extend its hyphae into the interior. ③ Spreading Seed Koji After cooling the steamed rice to an appropriate temperature (approx. 35-40℃), seed koji (spores of koji mold attached to a carrier) is sprinkled evenly. Currently, seed koji is manufactured and sold by specialized業者 called "moyashi-ya" (seed koji makers), with a history dating back to the Muromachi period. ④ Management in the Koji Muro: The True Skill of the Craftsman In the koji muro, where temperature and humidity are strictly controlled (35-40℃, approx. 90% humidity), the hyphae are propagated over approximately 48 hours. During this time, brewers "teire" (tend to) the rice by hand every few hours to equalize the temperature and control the growth of the hyphae. Entering the koji muro at 2 or 3 AM is a reality of sake brewing. To make good koji, "sleepless vigilance" is literally required at times, and the brewers' hands are always warm, imbued with the sweet aroma of rice. The optimal temperature for koji mold growth is approximately 30-35°C for hyphal growth and 25-30°C for spore formation. While master brewers of the past understood this through experience, our brewery manages the optimal timing for tending and room temperature by managing data with IoT. Health and Nutritional Benefits of Rice Koji: The Scientifically Proven Blessings of Fermentation In recent years, rice koji has also gained attention as a health food. Production of Vitamins and Essential Amino Acids Through the metabolism of koji mold, B vitamins (B1, B2, B6, niacin, etc.) are produced. Furthermore, the amino acids produced by proteases include essential amino acids, increasing its nutritional value. Presence of Functional Peptides Fermented foods derived from koji have been reported to contain ACE-inhibitory peptides that have blood pressure-lowering effects (Itou & Akahane, 2004, and others). Scientific evidence like this is behind the attention given to shio-koji and amazake as health foods. Reference: From the Consumer Affairs Agency's "Status of Analysis after Notification of Foods with Function Claims" Impact on Gut Environment Polysaccharides and peptides derived from koji mold in koji-fermented foods are suggested to contribute to the improvement of the gut microbiome (gut flora). With the recent advances in gut microbiome research, the focus on the functional properties of fermented foods is further increasing. Types and Uses of Rice Koji: Explained from a Sake Brewery's Perspective The properties of koji vary greatly depending on the strain of koji mold and culture conditions. Yellow Koji (Kikouji): The Main Player in Sake, Miso, and Soy Sauce This is the most widely used koji. Since it produces less citric acid, it results in sake with low acidity and delicate, fruity characteristics during brewing. White Koji (Shirokouji) and Black Koji (Kurokouji): Giving Shochu its Character Koji traditionally used in shochu brewing in Okinawa and Kyushu regions. It produces a large amount of citric acid, which is effective in preventing contamination by miscellaneous bacteria. Black Koji (Aspergillus luchuensis) is the traditional koji for Awamori, and white koji was discovered as a mutant strain of it. In recent years, there have been increasing efforts to apply white koji to sake brewing, and "white koji-brewed sake" with a sharp acidity different from traditional yellow koji has become a topic of discussion. The Future of Koji Making from a Sake Brewery's Perspective I believe that traditional handcrafted koji-making will continue to retain its value. However, at the same time, advancements in science and technology also offer new possibilities for koji research. Research on improving functionality using koji mold genome information, and at our brewery, while various sensors manage temperature and humidity, major companies are developing automated koji muro management systems utilizing AI and sensor technology. The integration of tradition and innovation is progressing. What we value is using our hands with a scientific understanding. We trust the numbers displayed by temperature sensors and data loggers, but ultimately, we make judgments by smelling the koji, touching it with our hands, and observing its color. That is the job of a sake brewery's master brewer. Conclusion: Rice Koji is a "Living Cultural Asset" Rice koji is not merely a tool for fermentation. I believe it is a "living cultural asset" that has been cultivated over hundreds of years in Japan's climate and passed down from craftsman to craftsman. Koji mold Aspergillus oryzae is Japan's "national fungus," with its safety and functionality proven at the genomic level. Rice koji supports the world's only brewing technique of multiple parallel fermentation, producing the taste, aroma, and nutrition of fermented foods through its rich enzyme group, including amylase and protease. Koji making is a precise technique that combines the management of temperature, humidity, and time with the five senses of the craftsman, and scientific research on its health functional properties is also rapidly progressing. For a sake brewery, koji is the "beginning of brewing" and the "life of sake." Next time you pick up sake or miso, I hope you will give a little thought to the work of the koji masters behind it and the unseen activities of the microorganisms.
コップ酒

Rare Blog of a Novice Brewer

What's the difference between "Sake" and "Other Brewed Alcoholic Beverages"? Understanding Japanese Alcohol Classifications by Production Category

on Apr 21 2026
Sake, doburoku, and nigorizake — they seem similar but are completely different. This article thoroughly explains the differences between the two categories defined by the Liquor Tax Act, based on their production methods, ingredients, and shipping requirements. 1. "Sake" and "Other Brewed Alcoholic Beverages": What are the distinctions under the Liquor Tax Act? In Japan, the manufacturing and sale of alcoholic beverages are strictly regulated by the Liquor Tax Act. Please note that manufacturing or selling without a license is a legal violation. The Act broadly classifies alcoholic beverages into four types: "Sparkling Alcoholic Beverages," "Brewed Alcoholic Beverages," "Distilled Alcoholic Beverages," and "Mixed Alcoholic Beverages." Within brewed alcoholic beverages, there are further categories such as "Sake," "Synthetic Sake," "Fruit Wine," and "Other Brewed Alcoholic Beverages." Most of what is generally referred to as "Japanese sake" falls under the legal definition of "Sake" under the Liquor Tax Act. Other beverages, such as what is commonly known as "doburoku" and certain fermented drinks, may be classified as "Other Brewed Alcoholic Beverages." These two categories, while seemingly following similar production methods, are fundamentally different in terms of the requirements stipulated by the Liquor Tax Act. These differences are summarized along three axes: "Filtration Obligation," "Additives Regulation," and "Range of Ingredients." Liquor Tax Act, Article 3 (Excerpt and Summary) Sake refers to an alcoholic beverage made by fermenting rice, rice koji, and water, which has been filtered, and has an alcohol content of less than 22 degrees (addition of sugars, organic acids, etc. is permitted under certain conditions). Reference: National Tax Agency, Interpretation of Laws, Article 3, Definition of Other Terms What is noteworthy here is the phrase "has been filtered." To be shipped as sake, the moromi (mash) must always be filtered. This is the fundamental difference from "Other Brewed Alcoholic Beverages." 2. Main Differences ①: Whether there is an obligation to filter moromi (mash) In sake production, the stage where rice, rice koji, and water are prepared and fermented is called moromi. If this moromi remains as is, it is "doburoku (turbid moromi)." Incidentally, while moromi cannot be filtered in the case of other brewed alcoholic beverages, if it has separated into clear liquid and sediment over time, simply scooping out the clear liquid is considered filtration. Sake Filtration is a mandatory condition Under the Liquor Tax Act, moromi must be filtered to be manufactured and shipped as "sake." Separation of rice solids (sake lees) and liquid (sake) through filtration is a legal requirement. Shipping in doburoku form is not permitted under a sake license. Other Brewed Alcoholic Beverages Can be shipped without filtration With a license for "Other Brewed Alcoholic Beverages," moromi can be shipped as a product in its unfiltered doburoku or turbid state. The recent "Doburoku Special Zone" system also utilizes this category. This regulation has a significant impact on practical operations. For example, when farm stay operators or small local businesses utilize the "Doburoku Special Zone" system to manufacture and sell doburoku, they often obtain a manufacturing license for "Other Brewed Alcoholic Beverages." While a sake license requires moromi to be filtered to a clear state before shipping, a crucial reason is also that new brewing licenses for sake, shochu, and mirin are not currently being accepted. Furthermore, this difference directly affects the appearance of the product. Filtered sake generally results in a transparent to pale yellow liquid, whereas doburoku, classified as other brewed alcoholic beverages, is sold in a cloudy, white state. Recently popular "nigorizake" belongs to the sake category. This is because it satisfies the "filtered" requirement by either intentionally adding back a small amount of sediment after initial filtration, or by using a coarser filter cloth to leave a trace amount of solids. 3. Main Differences ②: Regulations regarding additives during fermentation Another important axis distinguishing sake from other brewed alcoholic beverages is the range of ingredients and additives that can be introduced during fermentation. Sake Strict restrictions on additives during brewing During fermentation (brewing process), only items listed by the Liquor Tax Act can be added. Primarily rice, rice koji, and water, with sake lees, brewing alcohol, sugars, organic acids, amino acids, etc., permitted only under certain conditions. In principle, "unlisted" ingredients such as agricultural products cannot be added during fermentation. Other Brewed Alcoholic Beverages Relatively flexible with additives during fermentation Other brewed alcoholic beverages can be manufactured by adding ingredients "other than rice, koji, and water"—such as fruits, vegetables, herbs, dairy products—during fermentation. This allows for the creation of craft-style fermented beverages with unique flavors, while still being sake-based. In sake, the ingredients that can be used for brewing are explicitly stipulated by the Liquor Tax Act. For example, directly adding yuzu or plums to the fermenting moromi is not permitted under a "sake" manufacturing license (if fruit juice is added to finished sake, the category becomes liqueur, requiring a different license). On the other hand, in the category of other brewed alcoholic beverages, it is sometimes possible to incorporate such "unusual ingredients" into the fermentation process, which has gained attention amid the recent craft fermented beverage boom. For example, fruit doburoku, which adds fruits during fermentation while based on rice and koji, is one such example. 4. Main Differences ③: Range of usable ingredients Sake is primarily made from "rice, rice koji, and water." The definition of sake in the Liquor Tax Act includes the phrase "made by fermenting rice, rice koji, and water, which has been filtered," which sets the minimum conditions for sake. The addition of alcohol or sugars is permitted if statutory requirements are met, but only within the scope of "sake." Key Point: Sake Ingredient Regulations (Overview) Main ingredients permitted for sake: Rice, rice koji, water, sake lees, brewing alcohol (less than 36% alcohol by volume), sugars, organic acids, amino acid salts, starch syrup, coloring agents, etc., limited to items specified by the Cabinet Order for the Liquor Tax Act. Reference: Overview of the "Sake Production Quality Labeling Standards" In contrast, "Other Brewed Alcoholic Beverages," as the name suggests, is a broad category that encompasses brewed alcoholic beverages that do not fall under the definitions of sake, synthetic sake, fruit wine, beer, etc. They can use grains and sugars as primary ingredients, and other things as secondary ingredients, such as products made with herbs or hops. 5. Comparison with specific examples Case ①: Doburoku Special Zones and direct sales from farmers With the "Structural Reform Special Zone" system initiated in 2003, farmers and farm stay operators in specific regions became able to locally produce and sell doburoku on a small scale. This doburoku is manufactured under a license for "Other Brewed Alcoholic Beverages," and due to its special zone status, there are also regulations that only doburoku can be produced. It is expanding through regional revitalization and promotion of farm stays, with special zones now existing nationwide, including Takatsuki City in Osaka. Case ②: Is nigorizake sake or other brewed alcoholic beverages? Most "nigorizake" sold commercially is classified as sake. This is because it meets the legal requirement of "filtration" by passing the moromi through a coarse cloth, a process called "arakoshi" (coarse filtration). Although it appears cloudy, it is legally filtered sake under the Liquor Tax Act. On the other hand, doburoku, which is not filtered at all, falls under the category of other brewed alcoholic beverages. Case ③: Craft sake made by fermenting rice and fruit together In recent years, craft fermented beverages have emerged that are based on rice and koji but also incorporate herbs or fruits during fermentation. Since these use ingredients outside the scope of sake's ingredient regulations in the fermentation process, they are often produced as "Other Brewed Alcoholic Beverages," and this is indicated on the label. Case ④: Junmai-shu and Honjozo-shu "Junmai-shu" is sake made only from rice, rice koji, and water, without the addition of brewing alcohol. "Honjozo-shu" is sake with a small amount of brewing alcohol added. Both are legally classified as "sake" under the Liquor Tax Act. Both undergo a moromi filtration process, making them a completely different category from doburoku; doburoku cannot be called junmai-shu. Our brewery refers to this as junmai brewing. 6. Table: Sake vs. Other Brewed Alcoholic Beverages Comparison Item Sake Other Brewed Alcoholic Beverages (e.g., Doburoku) Moromi Filtration Mandatory (legal requirement) Not required. Can be shipped unfiltered Main Ingredients Primarily rice, rice koji, water Can also use ingredients other than rice, koji, water Additives during fermentation Only legal items (strict enumeration) Relatively high degree of freedom Appearance Transparent to pale yellow (nigorizake is exceptionally cloudy) Mostly cloudy/opaque Representative Examples Junmai-shu, Ginjo-shu, Honjozo-shu, Nigorizake Doburoku, craft fermented beverages Legal Basis (Liquor Tax Act) Article 3, Item 7 (Definition of Sake) Article 3, Item 19 (Definition of Other Brewed Alcoholic Beverages) License Category Sake Manufacturing License Other Brewed Alcoholic Beverages Manufacturing License 7. Summary: What the two categories signify "Sake" and "Other Brewed Alcoholic Beverages" both share the commonality of being fermented beverages made from rice, koji, and water, yet they differ distinctly in terms of the requirements stipulated by the Liquor Tax Act. Sake is bound by two restrictions: "must be filtered" and "ingredients limited to statutory items," which serves as the institutional backing to preserve traditional sake quality. On the other hand, "Other Brewed Alcoholic Beverages" is a category freed from these restrictions, offering a more flexible manufacturing license option for farmers in Doburoku Special Zones and manufacturers creating new craft fermented beverages. Sake must always filter moromi; cannot be shipped as doburoku Other brewed alcoholic beverages can be shipped unfiltered; Doburoku Special Zones utilize this license Ingredients and additives that can be used in sake brewing are limited to those enumerated in the Liquor Tax Act Other brewed alcoholic beverages have the flexibility to add ingredients other than rice, koji, and water during fermentation Commercially available "nigorizake" is sake that has undergone coarse filtration, legally distinct from doburoku Junmai-shu, Honjozo-shu, and Ginjo-shu are all classified as "sake" When choosing sake, simply checking whether the label says "Sake" or "Other Brewed Alcoholic Beverages" can reveal the institutional framework within which the product was created. Understanding the legal mechanisms behind alcoholic beverages might just be an entry point to enjoying sake more deeply.
工程

Rare Blog of a Novice Brewer

The Science of Sake Fermentation: A Precise Brewing Process Woven by Koji, Yeast, and Lactic Acid Bacteria

on Apr 20 2026
Sake is not just a simple "alcoholic beverage." First, it is a uniquely complex fermented beverage, starting from the starchy substrate of white rice, where multiple microorganisms divide roles to perform stepwise transformations. Let's unravel that fermentation process from the perspective of microbiology and biochemistry. 1. Koji-making Process: Building a Platform for Enzyme Production The first key to sake brewing lies in the koji-making process by Aspergillus oryzae (koji mold). It begins by scattering koji mold spores onto steamed rice that is firm on the outside and soft on the inside. The steamed rice, inoculated with tane-koji, is then cultivated in a koji room (koji-muro) with precisely controlled temperature and humidity for about 48 hours.During this time, the koji mold extends its hyphae into the rice grains and secretes a wide variety of hydrolytic enzymes. Particularly important is the production of amylases (α-amylase and glucoamylase) and proteases.α-amylase hydrolyzes the α-1,4-glycosidic bonds of starch in an endo-type manner to produce dextrin, and glucoamylase sequentially releases glucose from its ends.This two-stage saccharification reaction supplies fermentable monosaccharides to the yeast.Protease breaks down proteins into amino acids and peptides, serving as a nitrogen source for yeast in subsequent processes and acting as a precursor to umami components in sake. While using technical terms, essentially, koji mold breaks down rice, which is a lump of starch, into sugar, making it easier for the yeast in the next step to break it down into carbon dioxide and alcohol. 2. Shubo (Yeast Starter): Selection of Microbial Flora and Yeast Proliferation Next, koji obtained from koji-making, steamed rice, water, and yeast are brewed in a small tank to cultivate a high-density yeast culture solution called "shubo" (moto). In traditional kimoto and yamahai-moto methods, wild lactic acid bacteria (of the Lactobacillus genus, etc.) are naturally propagated, but this is rarely done in modern sake brewing.Instead, in the modern mainstream sokujo-moto method, instead of propagating lactic acid bacteria like in kimoto or yamahai-moto, brewing lactic acid is directly added. Homo-lactic acid fermentation by lactic acid bacteria (C₆H₁₂O₆ → 2CH₃CH(OH)COOH) rapidly lowers the pH of the moromi (main mash). This pH drop acts as a selective pressure, eliminating miscellaneous bacteria that are weak to acidic conditions, while giving an advantage to the proliferation of acid-resistant brewing yeast (Saccharomyces cerevisiae). At this stage, the yeast enters its exponential growth phase, increasing cell density in preparation for the subsequent moromi fermentation. The acidification of the moromi aims to eliminate miscellaneous bacteria that could negatively affect brewing by making the acidic environment unsuitable for their survival. In this environment, yeast, being strong against acid, can perform its function without being destroyed along with other miscellaneous bacteria. 3. Moromi Fermentation: A Globally Rare Fermentation Method Called Parallel Multiple Fermentation The greatest characteristic of sake is this concurrent saccharification and fermentation. Unlike beer, where saccharification and fermentation are separated, in sake, saccharification by koji and alcohol fermentation by yeast proceed simultaneously within the same tank. This is an extremely rare fermentation method among brewed beverages worldwide. The gradual addition of koji rice, steamed rice, and water in three stages ("hatsugoe," "nakagoe," and "tomegoe") during "sandan-jikomi" (three-stage preparation) is also to maintain the substrate concentration within an appropriate range relative to the yeast cell density and to prevent a decrease in yeast activity due to osmotic stress. Furthermore, this operation, combined with low-temperature, long-term fermentation (approximately 20-30 days), promotes the production of aromatic components (isoamyl acetate, ethyl caproate, etc.), forming a complex flavor profile. The central reaction of alcoholic fermentation is the production of ethanol via glycolysis (Emden-Meyerhof-Parnas pathway): C₆H₁₂O₆ → 2C₂H₅OH + 2CO₂. The alcohol concentration at the end of fermentation reaches 14-20%, which is close to the upper limit of the yeast's own alcohol tolerance. Ultimately, the power of yeast transformed it into carbon dioxide and alcohol through fermentation, but as the alcohol concentration increases, the yeast also dies off. 4. Joso and Hi-ire: Termination of Fermentation and Stabilization of Quality Once the moromi has matured, it undergoes a solid-liquid separation process called "joso" to be separated into sake and sake lees, resulting in clear sake. Afterward, in most cases, hi-ire (pasteurization) is performed. Even after separation from sake lees, there are still living yeast cells, so a short-time heat treatment at 60-65℃ is carried out to inactivate residual wild yeasts and lactic acid bacteria, and to deactivate enzyme activity (especially residual amylase). This concept of pasteurization, a technology uniquely developed in Japan, is said to predate Western Pasteur (named after the person who elucidated the principle of wine making from grapes) by about 300 years. Sake fermentation is a precise biological process where microbiology, enzyme chemistry, and food engineering intersect. Koji mold, lactic acid bacteria, and yeast each occupy different spatiotemporal niches and cooperate to create that clear cup of sake. Although sake is consumed worldwide, the method of sake production is uniquely Japanese, as this story explains.
希米ラベル

Rare Blog of a Novice Brewer

How the name "Kimama" came to be

on Apr 19 2026
How was the brand "Kimama" born? Please read the secret story behind the brand name, which conveys gratitude for the rare rice of local farmers and the desire to deliver its "unadulterated" deliciousness. This name was chosen after considering many candidates, including the classic auspicious words "Chiten Tai" from the I Ching, the Buddhist term "Uchouten," and the potter Hanjiro Kawakita's pseudonym "Kimama."
袋吊り

Rare Blog of a Novice Brewer

to seriously embark on sake brewing

on Apr 14 2026
Ready to start brewing sake I thought I could start brewing sake as soon as I got my license, but preparing after getting the license has been surprisingly tough. Sake brewing involves steaming rice, mixing it with koji and water, and adding yeast, but there are countless other tasks and responsibilities.   Things that can only be done after getting the license Reporting the recipe to the tax office. Label design application Registering facility equipment Ordering reagents for analysis during brewing Ordering yeast etc For a new sake brewery like ours, we have zero approved recipes, so we have to apply for everything. Also, there are things like yeast that cannot be purchased without a license. Preparing all of that took two months. Can only use Windows For applications and declarations related to sake brewing and sales, e-Tax, an online registration system, is essential, and paper applications are frowned upon. With paper applications, the application form is mailed to a dedicated counter, where it's digitized into a PDF and then delivered to the sake department, which reportedly takes about a week. However, with e-Tax, applications can be viewed immediately, so the sake official recommended e-Tax, or rather, requested it. So, I decided to try e-Tax. Upon investigation, I found that while there are online options, applications for sake-related matters can only be done by installing software. Furthermore, it's a system where you verify your identity by reading your My Number Card with a card reader, but I don't have a My Number Card, so I wondered what to do. I found out that it's possible to proceed by preparing documents containing the company's registration information. However, this also costs about 8,000 yen for 27 months. Creating a My Number Card would take time, and I couldn't do anything during that period, so I gave up, paid the fee, and applied for the documents with the company's information. I thought this would allow me to apply, but there was another pitfall... My computer is a Mac, so that was out. Reluctantly, I borrowed my wife's computer, installed e-Tax, created an account, and completed only the minimum necessary applications. Sake brewing not only requires applications but also monthly declarations of sales performance. Borrowing my wife's computer every time would be difficult, so I gave up and looked into buying a used Windows laptop, but models from about five years ago were selling for tens of thousands of yen. Apparently, WIN11 is installed, but will it run properly? I'm also worried it might break down quickly. On the other hand, new ones cost over 100,000 yen, and those with low specs are too slow to be usable. Found a MINI-PC It's a desktop computer without a monitor, keyboard, or mouse, but if I can use it remotely from my Mac, I don't need a monitor, keyboard, or mouse to operate it from my Mac. This perfectly matches my needs. Moreover, the price is incredibly cheap at around 30,000 yen. The specs are also perfectly adequate, and it runs smoothly. Normally, I use my Mac, but when I need to use e-Tax, I just boot up this MINI-PC and make the applications. A monitor and keyboard are only needed during setup, but I used the TV as a monitor and the keyboard I used before switching to Mac. Now I can finally start as a brewer Two months passed in a flash. I was so excited about getting the license and had so many things to do that some tasks were left incomplete or inadvertently overlooked, causing time to slip by. Anyway, Sugimoto Sake Brewing is starting.  
居酒屋でビールで乾杯

Rare Blog of a Novice Brewer

10 Surprising Doburoku and Oily Fish Pairings, Plus Other Dishes That Go Well With Doburoku

on Mar 23 2026
Among food enthusiasts, the ultimate pairing whispered about is "doburoku x blue fish." This involves fatty fish like mackerel, sardines, and saury, combined with doburoku, a cloudy sake. While seemingly surprising, this combination actually has scientific and cultural backing.