Bitter is the new sweet

Bitterness… is it really always a bad thing? 

Not according to Toshihiko Koseki, special advisor to the Yamagata Prefecture Brewers Association, who went so far as to develop a special variety of yeast that produces more bitter compounds!

An article in Nikkei Gooday by bitter sake-loving journalist Kaori Haishi opens by highlighting a recent resurgence in appreciation for bitterness: premixed canned chuhai flavoured with bitter fruit peel, and desserts or chocolates with bitter elements.

But how can bitterness be accepted as a positive when it’s actually listed as an off-flavour in the evaluation sheets of the National New Sake Appraisal (aka the Annual Japan Sake Awards, 全国新酒鑑評会, zenkoku shinshu kanpyokai)?

Toshihiko Koseki has a short answer–bitterness builds depth. In wine, it’s even welcomed as a noble note that adds a special something to the flavour profile. 

Although yeast is best known for converting sugar to alcohol in the brewing process, it also contributes aroma compounds, acids, amino acids and bitter compounds. [The last two can even be the same thing.] TY24, the yeast that Koseki developed with the Yamagata Research Institute of Technology, produces large quantities of the bitter-tasting compound tyrosol, derived from the amino acid tyrosine. TY24 was developed in 2003 over the course of a year by fairly old-school methods–DNA damage induced by UV radiation and chemicals to produce mutant strains, followed by selection of strains that still fermented well and produced a well-balanced profile that incorporated a higher degree of bitterness, and finally test brewing and commercialisation.

Koseki doesn’t expect everyone to love sake that contains more bitterness straight away. He compares it to gradually coming to appreciate bitter foods as you grow up, like certain vegetables that everyone hates as a child.

Other than adding depth and complexity, bitterness plays an important role in pairing. Although it’s traditionally said that sake doesn’t fight with food, or more accurately that it doesn’t dictate what food it can be served with, Koseki argues that sweet and aromatic sake only goes with a limited range of dishes. In contrast, less aromatic sake with more lingering notes and an element of bitterness highlights the flavours in food, cleans the palate and encourages the drinker to keep eating.

And the addition of bitterness in the flavour profile not only makes sake able to pair beautifully with bitter foods, it also gives it enough presence to stand up to powerful flavours like salted anchovy or blue cheese. Koseki also points out that sake with bitterness is well suited to other cuisines, such as French and Chinese.

Plus, he adds, bitterness creates a sake that can be savoured slowly with food rather than quaffed as an aperitif, which can only be a good thing.

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日本酒の苦味は「大人の味」 フランス料理や中華にも合う (Nikkei Gooday, 4 June 2025, Japanese)