Chokaisan Junmai Daiginjo Nama Genshu

Chokaisan Junmai Daiginjo Nama Genshu

Regular price
$53.00 USD
Sale price
$53.00 USD
Regular price
Sold out
Unit price
Shipping calculated at checkout.

A previous release of sake was featured in the Sunflower Sake monthly club, February 2023. As a result, this product writeup is extra detailed! As of 12/23, it has been expanded to include information previously only shared with club members.

A bountiful (even chaotic?) array of fresh grape, crunchy green apple, strawberry, pear, peach and candied notes make a joyful impact on the palate, while a tangy finish of lactic mascarpone, white pepper and licorice root lend structure and bitterness. The texture is so smooth it’s almost creamy, coming across as sweeter than actually it is due to the super-soft Mt. Chokai water. At +2 SMV, Chokaisan is technically slightly dry-- but with a generous roundness that slips across the tongue.


  • Brewery: Tenju Shuzo
  • Location: Yashima village, Akita 
  • Water: Soft Mt. Chokai snowmelt which emerges from a nearby spring at a consistent 45F year-round. 
  • Rice: pesticide-free Miyamanishiki (grown within 10 km by contract farmers)
  • Polishing level:  50%
  • Grade: Junmai daiginjo muroka nama genshu 
  • SMV: +2
  • Yeast: ND-4 (Dianthus/Nadeshiko flower yeast) 
  • Starter: Sokujo
  • Alcohol: 17%


Store the unopened bottle in the refrigerator, ideally in the back (not the door) and consume within 6 months. At ~4-5 months old on arrival (FDA approval, transit, etc) this sake has had a chance to mellow out a bit and is really showing its best now. The astringency and bitterness have settled, the flavors have integrated. It’s going to be peaking from December to May. Once open, it’s delicious for at least a month (mellowing a little, and losing its effervescence, over the first few days). Keep tasting and continue to enjoy as long as it tastes good to you. 

How to pair & enjoy?

I sometimes struggle with pairing recommendations when the sake is as “loud” and expressive as this, but the “like with like” adage holds true: pair big flavors with big flavors. Hawaiian pizza, spicy tuna, dark chocolate, Olympia Provisions Loukanika or equally spiced and bright charcuterie, orange chicken (or faux chicken), sansho, ume, tsukemono and pickles.. A sweet protein like silken tofu, shrimp or uni will really bring out the fruit, while a more savory protein, like grilled flatiron, will benefit from something playful and spiced on top– chimichurri, or pepper rub– to keep up with the brisk moves of Chokaisan.

Enjoy chilled the first few days, playing with room temp and even gentle warming once it has mellowed in the fridge a bit. 

More backround on this particular sake:

There are two characteristics of primary importance in understanding the flavor and make of this sake. I’ve gone into some detail already on the history of flower yeast, but what does it mean for the flavor? Do the flower yeasts impart qualities of their host material? Does a sunflower sake taste of sunflower seeds?

The short answer is no, not really– but the power of suggestion is strong, and some are brewed in such a way that it echoes the flower of origin. Take Amabuki Ichigo: a junmai ginjo sake brewed with strawberry flower yeast. It’s juicy, fruity, aromatic, and reminds me of biting into a peak-season strawberry full of natural sweetness. Some of this is the yeast speaking, but Amabuki made brewing decisions that supported a strawberry-like outcome. Compare this to Amabuki marigold, which is an omachi junmai yamahai designed to be warmed. This is a case of embracing the innate characteristics of marigold yeast, which is earthy, slightly bitter, and full on the palate. 

So we come to Nadeshiko yeast, which is unique because it was one of the first hanakoubo to undergo private commercial testing at Tenju Shuzo. The resulting sake, Chokaisan daiginjo, was also the first hanakoubo sake ever to earn an award from Japan’s national new sake competition. Tenju has been iterating and improving Chokaisan for over 20 years now, racking up prizes on the way. No surprise then that ND-4 (nadeshiko yeast) is now the most popular hanakoubo in Japan (but by no means common). As you can see in the above chart, Nadeshiko yeast has a high level of ethyl caproate production which is associated with green apple, mint, strawberry and fennel aromas. A by-product of ethyl caproate is caproic acid, which we perceive as bitter, flinty and textural. In deft hands– and with a little bit of sweetness– caproic acid can be balanced into an intriguing structural element.

Second, this is a muroka nama genshu: an unfined (muroka), unpasteurized (nama), undiluted (genshu) sake. This is the freshly born, heart-beating, straight-from-the-tap version that captures the wild and untamed side of its pasteurized kin. It’s meant to be strong– it’s meant to be brash and unapologetic. Charcoal fining absorbs color, proteins, minute particulates, flavors and aromas – leading to a consistent, “clean” tasting, water-white sake that is very smooth (and sometimes very boring). Pasteurization makes sake shelf stable by killing microorganisms and deactivating enzymes, but it also decreases acidity, removes effervescence, mutes aromas, and pretty dramatically changes the flavor profile. Dilution makes sake easier to drink, easier to pair, more affordable– but by definition, less concentrated.


Tenju Shuzo dates to 1874, but its most significant accomplishments took place in the last 30 years. In a most unusual way, Tenju Shuzo– a very small, regional brewery– can trace its rise to consistent, collaborative R&D since the early 1980s. This is the sort of long-term vision we expect to see in huge breweries, not tiny backwater operations.

But in this 5000-person town blessed with pristine soft water and the perfect climate for sake brewing, 5th Generation Tenju Shuzo president Eikichi Ohi believed the key to making best use of these natural advantages was investing in the quality of their rice and yeast. To improve the rice, Tenju Shuzo was the first brewery in Japan to establish in 1983 a collaborative brewery-farmer agricultural research group. This was during a time when it was illegal to buy rice directly from farmers; as a result this was the only way to start a dialogue and collaboration to improve quality. With the goal of improving local sake rice year over year, even to this day members meet regularly to compare crop samples and share research outcomes. Since the 80s, they have coordinated on fertilizer additions, nutrient management, reduction (and eventual cessation) of pesticides, rice varieties, as well as harvesting and handling. The brewery’s newsletter is shockingly consistent, with bimonthly updates on rice planting, growth and harvests available on the website as far back as 1999!

To develop a yeast that would distinguish Tenju from its competitors, Ohi also joined forces with the Nodai (Tokyo University) fermentation science department to establish the Hanakoubo Kenkyoukai: Flower Yeast Research Association. Ohi served as president of the association for over a decade, leading efforts to isolate and promote yeasts from marigold, creeping rose, cactus flower, and of course nadeshiko (dianthus), which is used to ferment this award-winning junmai daiginjo. By drawing on the limitless diversity of wild yeasts that thrive on flowers, Tenju was able to set itself apart from the vast majority of breweries that craft sake with kyoukai kobo (government yeasts). 

The pasteurized version of this sake has won numerous international sake awards and is the flagship, and pride, of Tenju Shuzo. This muroka nama genshu version (unfined, unpasteurized, cask strength) is very limited and enters the US in tiny quantities each year.