Sake Brewing Schedule

Sake is made in winter.

This tradition, called “kan-zukuri” (cold-season brewing), makes scientific sense. Let’s follow a sake brewery’s annual schedule to see how sake is born.

Why Brew in Winter?

Reasons for Kan-zukuri

Climate Suitable for Low-Temperature Fermentation Temperature control is the most crucial aspect of sake brewing. Slow fermentation at low temperatures produces sake with a delicate, refined flavor. Winter’s cold serves as nature’s refrigerator.

Inhibits Bacterial Growth Harmful bacteria thrive in summer. The cold winter environment suppresses bacteria that could negatively affect sake production.

Agricultural Off-Season Labor Sake brewing was traditionally winter work for farmers. After the rice harvest, when fields were covered in snow, they worked as brewery workers. This was the origin of the “toji” (master brewer) system.

Availability of New Rice Sake is made using freshly harvested rice from autumn. The brewing season begins with rice at its freshest state.

Modern Sake Brewing

Today, with advanced refrigeration equipment, sake can be brewed even in summer.

Some breweries practice “shiki-jozo” (year-round brewing). Major manufacturers maintain stable supply by producing throughout the year.

However, many breweries continue traditional winter brewing. They believe that sake made using winter’s natural environment has flavors that cannot be replicated with equipment alone.

Annual Sake Brewing Schedule

July-August: Preparation Period

The preparation period before brewing begins.

Brewery Cleaning and Maintenance Washing tanks and equipment, inspecting facilities. A clean environment is fundamental to good sake brewing.

Securing Sake Rice Securing the sake rice for the year. Meetings with contract farmers and arranging purchases.

Planning What kind of sake will be made this year, and how much? Creating a brewing plan while considering sales projections.

September-October: Brewing Begins

As autumn arrives, sake brewing begins in earnest.

Rice Polishing The process of milling sake rice. The polishing ratio determines the sake’s character. For daiginjo, rice may be polished to 50% or less of its original size.

Washing and Soaking Washing polished rice and soaking it in water. Some breweries manage soaking time down to the second.

Steaming Rice is steamed in a large steamer called a “koshiki.” The steaming results affect all subsequent processes.

Koji Making (Seikiku) Growing koji mold on steamed rice. This is the most nerve-wracking part of sake brewing. Over about 48 hours, koji is made while strictly controlling temperature and humidity.

November-December: Peak Brewing Season

As temperatures drop, the peak brewing season arrives.

Shubo (Yeast Starter) Making Combining koji, steamed rice, water, and yeast to create shubo. Shubo is the starter for the main mash, cultivating a large amount of active yeast.

Three-Stage Addition (Sandan Jikomi) Koji, steamed rice, and water are added to the shubo in three stages, called “hatsuzoe,” “nakazoe,” and “tomezoe.” Adding gradually rather than all at once maintains an environment where yeast can work actively.

Moromi Fermentation In the tank, saccharification and alcohol fermentation occur simultaneously (multiple parallel fermentation). The process takes about 3-4 weeks of slow fermentation.

January-February: Pressing and New Sake

In the coldest period, new sake is born.

Pressing The finished moromi is pressed, separating sake from sake lees. Different pressing methods yield different flavors: “arabashiri,” “nakadori,” and “seme.”

Settling (Oribiki) Fine particles (ori) in freshly pressed sake are allowed to settle, and the clear liquid above is taken.

Pasteurization (Hi-ire) Heating to approximately 60-65°C for sterilization. This stops enzyme activity and stabilizes sake quality.

Storage Aging in tanks. Over time, the flavor becomes mellower.

March-April: Shipping and Review

The brewing season comes to an end.

New Sake Shipping Shipped as “shiboritate” (freshly pressed) or “shinshu” (new sake). Enjoy its fresh flavors.

Reviewing the Brewing Season Reflecting on this year’s brewing and organizing challenges for next year. Also preparing entries for sake competitions.

Brewery Cleanup Washing and storing used equipment. Preparing for the next season.

May-June: Rest and Preparation

Brewing ends, and the brewery becomes quiet.

Brewery Workers Return Home Seasonal brewery workers return to their hometowns for agricultural work.

Aging Sake Management Checking the condition of sake in storage. Continuing temperature control.

Competitions Sake competitions are held across the country, including the National New Sake Competition. For breweries, it’s a place where a year’s work is evaluated.

Until New Sake Arrives

Types of New Sake

Brewing begins in autumn, and new sake is pressed in winter. Names change depending on the timing.

Shiboritate (December-February) Sake immediately after pressing. Many are unpasteurized fresh sake. Fresh and robust in flavor.

Risshun Asashibori (February 4) Sake pressed on Risshun (the first day of spring) and delivered the same day. Popular as a good-luck charm.

Shinshu (Winter-Spring) A general term for sake made during that brewing year. Often refers to sake shipped by June 30.

Seasonal Limited Editions

Different styles of sake are shipped each season.

Summer Sake Light, refreshing sake made for summer. Some have lower alcohol content.

Hiyaoroshi (September-November) Sake pasteurized in spring, aged through summer, and shipped in autumn. Mellow with deep flavors.

Sake for Warming (Autumn-Winter) The season when sake that’s delicious when warmed increases. Mainly junmai-shu and honjozo.

What is the Brewing Year?

BY (Brewery Year)

Sake has a “brewing year.”

One year runs from July 1 to June 30 of the following year. For example, “BY2024” refers to sake made between July 2024 and June 2025.

Similar to wine vintages, but for sake, it indicates the brewing year rather than the rice harvest year.

Manufacturing Date on Labels

The “manufacturing date” on labels indicates when the sake was bottled.

The brewing year and manufacturing date may differ. For example, if BY2023 sake is bottled in March 2024, the manufacturing date will be March 2024.

If You Visit a Brewery

Best Times to Visit

Brewing Season (November-February) You can see sake brewing in action. Steam from rice steaming, bubbling moromi—experience sake brewing with all five senses.

Brewery Open Days (January-April) New sake debut events. Tasting and purchasing limited sake.

Things to Note

The brewing season is the busiest time for breweries. Some don’t accept visitors.

Always check before visiting. Reservations are usually required.

Summary

A summary of the sake brewing year:

Period	Main Activities
July-August	Preparation & Planning
September-October	Rice Polishing & Koji Making Begins
November-December	Peak Brewing Season
January-February	Pressing & New Sake Shipping
March-April	Shipping & Review
May-June	Rest & Aging Management

Behind every glass of sake is a year’s work. Since it’s sake made in harmony with the seasons, enjoy it while feeling the seasons.

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For more on the sake brewing process, see How Sake is Made.

For details about toji, see What is a Toji?.