What kind of sake is "fukurozuri"? The charm of unpressed, unpasteurized sake

Have you ever seen words like "Fukuro-tsuri" (Bag Drip), "Shizuku-zake" (Drip Sake), or "Tobin-tori" (Bottle Drip) on a sake label?

Many people probably feel that they sound special but aren't quite sure what makes them different.

What Nikkoni Taiyo Sake Brewery values most is this pressing method called Fukuro-tsuri.

This time, we will explain as simply as possible what Fukuro-tsuri sake is and why we insist on this method despite the effort and cost involved.

What is Fukuro-tsuri? The gentlest way to press sake, using only gravity

Sake is born through a "pressing" process that separates liquid (sake) and solid (sake lees) from "moromi" (fermented mash) made from rice, rice koji, and water. Even from the same moromi, different pressing methods can yield sake with entirely different characteristics.

In Fukuro-tsuri, moromi is filled little by little into cloth "sake bags," and these bags are simply hung.

Nothing else is done. Without using any machinery, only the drops that fall from the mouth of the bag, one by one, are collected, relying solely on gravity.

Only a very small amount of sake can be obtained from a single bag.

Many bags are hung, and it takes from one night to several days for a tank to finally fill up.

The terms "Shizuku-zake" or "Shizuku-tori" (drip sake) come from this image of collecting sake drop by drop.

Why "Fukuro-tsuri" instead of "pressing"?

Most common sake is pressed using "squeezing."

Squeezing methods include using automatic pressing machines (commonly called "Yabuta") or stacking sake bags in a box called a "fune" (boat) and applying pressure from above.

Both methods apply external pressure to the moromi to thoroughly extract the sake.

The advantage of squeezing is its efficiency.

80-90% of the moromi can be recovered as sake, and the process is quicker.

It is a very rational method for consistently delivering large quantities of sake.

On the other hand, Fukuro-tsuri applies no external force whatsoever.

Only about half of the moromi can be recovered as sake. The rest becomes sake lees, still containing sake.

It's time-consuming, labor-intensive, and yields little. Frankly, it's a very inefficient method from a business perspective.

Nevertheless, we choose Fukuro-tsuri because there's a taste that can only be created by "not pressing."

Looking across Japan, very few breweries press sake for sale using Fukuro-tsuri.

Many breweries reserve it for very small quantities, such as special bottles for competitions.

Why Fukuro-tsuri sake doesn't have "off-flavors"

When pressure is applied to sake, the rice cells are crushed, squeezing out components that ideally shouldn't be in the sake.

These are the so-called "off-flavors" that contribute to astringency, harshness, and heaviness. The more intensely the sake is pressed in the later stages, the stronger these off-flavors become.

With Fukuro-tsuri, there is no "pressing" process to begin with. What drips from the bag is only the clearest part, which has naturally become liquid within the moromi. The sources of off-flavors are physically prevented from appearing.

This is not about "removing off-flavors," but rather about "not producing off-flavors from the start." Instead of subtracting later, we simply avoid adding anything unnecessary from the beginning. This is the sole reason why Fukuro-tsuri sake has such a clear taste.

Furthermore, the choice not to "pasteurize"

This is another commitment of Nikkoni Taiyo Sake Brewery.

Most sake undergoes "pasteurization" (heating sterilization) once or twice after pressing. Pasteurization stabilizes the quality and makes it easier to store for a longer period. It's a very important technique.

Our Fukuro-tsuri sake, however, intentionally skips pasteurization and is generally delivered "nama" (unpasteurized). Because it's not heated, the fresh aroma, juiciness, and sparkling freshness of freshly pressed sake remain intact. It's a drop of sake pressed without off-flavors through Fukuro-tsuri, and furthermore, kept "nama," meaning it's in its purest state.

However, unpasteurized sake is very delicate.

After delivery, we ask that you store it refrigerated (more details in the latter half of the article).

Less alcoholic sharpness, a mellower feel

Those who try Fukuro-tsuri sake often comment on its "less pungent alcoholic sensation" and "softness."

There are several reasons for this, but one is believed to be that by pressing without mechanical stimulation, the state where water and alcohol are well blended in the sake (scientifically called "hydrogen bonding") is easily maintained. The more thoroughly water and alcohol are mixed, the milder the pungent sensation of alcohol alone feels.

Regarding this "blending" of water and alcohol, we have a separate article that delves into it in detail, including scientific papers. If you want to know more, please read it as well.

Doburoku and Fukuro-tsuri: The same philosophy of "not adding, not destroying"

The oldest form of sake is "Doburoku," made by fermenting only rice, koji, and water, and then consuming it unfiltered.

It's a rustic, powerful sake, cloudy white and thick, allowing you to fully enjoy the texture of the rice grains, its sweetness, and the vibrant flavors of fermentation.

Doburoku is a sake that "preserves everything as it is."

Fukuro-tsuri is a sake that "only takes what comes out naturally." Although they seem opposite at first glance, the underlying philosophy is the same.

Both involve the brewer not interfering unnecessarily, and trusting in the power of rice and the expanding fermentation.

This honesty of not adding, not destroying, and not deceiving, directly translates into the taste.

Nikkoni Taiyo Sake Brewery's motto, "Sincerity over efficiency," comes from this.

During brewing, we monitor continuously with IoT, but for the final pressing, we rely on gravity.

It's the best of both technology and craftsmanship.

We want to deliver the inherent voice of the rice in its most honest form. That is what Fukuro-tsuri sake means to us.

How to deliciously enjoy Fukuro-tsuri sake

Since it's such a precious drop, we'll introduce the best ways to bring out its charm.

Temperature: First, chill it well. Around 10°C, the clear aroma and crisp finish stand out. If you let it warm up slightly, the sweetness of the rice will expand, allowing you to enjoy two delicious experiences from one sake.

Glassware: A wine glass with a small opening or a guinomi cup is recommended. The aroma will gently rise, and you can directly experience the clear, off-flavor-free taste. Larger wine glasses are also recommended.

Food pairing: Choose dishes that don't overpower its delicate flavor. It pairs well with light Japanese flavors such as white fish sashimi, simmered dishes seasoned with dashi, or tempura enjoyed with salt.

Storage: Always keep it refrigerated. Especially unpasteurized sake, which is unheated, relies on freshness. To best enjoy its freshly pressed character, consume it as soon as possible after opening, ideally within a few days.

Summary: Fukuro-tsuri is a "subtractive" sake, "not pressed, not added"

Fukuro-tsuri is the gentlest and most luxurious way to press sake, extracting it drop by drop using only gravity, without applying pressure.

Because it's not pressed, no off-flavors emerge, and because it's not pasteurized, its freshly pressed freshness remains intact.

This creates a mellow mouthfeel where water and alcohol are well integrated.

The yield is low, and it requires a lot of effort. Still, we want to deliver the pure taste that rice inherently possesses.

With that in mind, Nikkoni Taiyo Sake Brewery continues to hang its bags today.

This is a drop of sake we confidently recommend to anyone who wants to "try a special Japanese sake." Please experience the difference of sake pressed without pressure with your own palate.