SHIRIN Oak Cask Storage Unlocks New Potential for Sake

In July, 2020 SAKE HUNDRED introduced the newest entry into its sake family: The premium oak-casked Shirin.

Made with Yamada-nishiki rice polished to 18% by a renowned Yamagata brewery, Shirin is, uniquely, allowed to age for nine days in casks of mizunara Japanese oak, bringing out woody notes in the final product that lend an elegant and pleasant tension against its junmai daiginjo aromas.

While common in drinks like wine and whiskey, barrel aging is largely unprecedented in the world of sake and makes Shirin a trailblazing, one-of-a-kind beverage that offers a truly unique sake experience.

A Tartness to Elevate the Junmai Daiginjo Experience

SAKE HUNDRED prides itself on a full lineup of sake that feature unprecedented clarity and elegance, free of imperfections. Shirin, however, adds a distinctive tartness. This tartness is by design, to play off of the aromas and flavor notes imparted by the oak barrel aging process and to give a sturdy backbone to the drinking experience — a signature of the Shirin flavor profile.

Produced by Ou-jiman Brewery in Tsuruoka, Yamagata Prefecture, Shirin is one of the brewery’s crowning achievements. Long renowned for masterfully incorporating pleasant and balanced tartness into their sake brews, Ou-jiman has proven indispensable in engineering Shirin with a tartness that supports its woody aromas and realizes the Shirin concept.

A Perfect Partner to Japanese Oak

Barrel storage of sake can influence flavors and aromas in exciting and unexpected ways. The length of storage, storage conditions and even the way the barrel is baked and treated all play a role. But the biggest question in developing the Shirin concept was simply what kind of barrel to use.

American and French varieties of oak cask are commonly used in the aging process of other drinks. Shirin, however, is rested within barrels of Hokkaido mizunara oak — a variety native to Shirin’s birthplace of Japan that is sometimes called, simply, “Japanese oak.”

For Shirin’s delicate flavors and aromas, American oak — while cheap to acquire — proves too strongly-scented, releasing competing aromas into the aged product. French oak, on the other hand, commands a high price, features distinctive characteristics of vanilla and is the storage method of choice for many luxury white wines.

Japanese oak, however, contributes its own unique qualities. With its delicately botanical aromas, Japanese oak is several times more expensive than French oak, but earns its price tag with distinctive, forest-like characteristics that perfectly complement and enhance the Shirin as it ages.

The result is an exquisite balance of fragrance and flavor that’s at once dignified and incongruous, the Japanese oak providing Shirin with juxtaposing characteristics that first seem pleasantly at odds, before melding into a unified profile.

While Japanese oak proves the perfect match for the Shirin concept, the question of ideal storage time remains.

The issue at the heart of storage time is generally intuitive, yet a precarious balancing act: Store too long, and the flavors and aromas imparted by the storage cask will become too strong. A short storage, however, may result in changes that go unnoticed.

With Shirin, the intent was an aroma that’s subtle at first sniff, yet becomes more apparent and pronounced as it’s further explored. To achieve this ideal during Shirin’s development, SAKE HUNDRED simply placed the junmai daiginjo into Japanese oak storage casks and closely monitored the developing aromas and flavors day by day.

In early days of storage, the Japanese oak cask aromas have yet to fully integrate, resulting in characteristics that are too raw and pronounced. By day five, the flavors have started to blend with the Shirin, further growing in natural harmony as additional days pass. It is then a question of how long this harmony can be developed before becoming unbalanced again.

The answer, it turns out, is nine days.

To further preserve this harmonious flavor profile, Shirin is cask stored unpasteurized. Additionally, the inner surfaces of the storage barrels are gently toasted to treat the wood and preserve subtle nuance in the finished Shirin.

The perfect storage time, in a perfectly complementary wooden cask, treated in such a way as to preserve the dignified subtleties of the finished product. These processes combine to make Shirin what it is: A truly unique sake experience.

Delicate, Yet Deep

The subtle nuances provided by the Japanese oak cask aging process are not immediately apparent when pouring a glass of Shirin. But these ethereal touches announce themselves to those who seek them.

A silky mouthfeel gives way to an acidic backbone, and the unmistakable presence of oak materializes through Shirin’s dignified flavors.

Shirin is best enjoyed at a temperature of 6°C, where its unrivaled clarity and delicacy are most pronounced. Enjoyed slowly, Shirin gradually reveals more confident oak accents as its chilled temperature gently rises.

The characteristics of oak meld harmoniously with a junmai daiginjo canvas, resulting in flavors that are subtle and nuanced. Shirin is a quiet and unassuming sake, revealing its hidden joys with contemplative drinking.

Delicate and quiet, yet pleasantly tense. Shirin’s idiosyncratic nature is its greatest strength, revealed only to those who take the time to explore it.