NicoNico News reports not only that there's a "low carb" sake, but that it's celebrating its 10th anniversary.
Gekkeikan launched its Tōshitsu Zero (糖質ゼロ, "zero carb") range in 2008, and is improving the quality of the sake and refreshing the packaging to celebrate 10 years on sale. It was the first low-carb sake in Japan, made with as little carbohydrate as possible, resulting in a super-light, super-dry style.
Gekkeikan's research department use their own specially bred yeast for brewing, reducing acidity to a minimum to improve the balance and produce a fresh, clear dry sake.
Tōshitsu Zero is Japan's best-selling low-carb sake, sold in a 2.7 L pack for JPY 1,995, a 1.8 L pack for JPY 1,396, a 900 ml pack for JPY 716 and a 210 ml "large cup" for JPY 160 (to be launched in September 2018). It's aimed at drinkers who want to reduce their carbohydrate intake, and those who want a very light and dry sake to go with food. Gekkeikan's product dominates the low-carb sake market with about 50% share.
They launched Karoyaka Junmai, with 20% less calories and 30% less carbohydrate, in 2004, followed by a product with 85% less carbohydrate in 2008. In response to continuing demand, they released Tōshitsu Zero in 2008, and continue to improve their brewing technique for this specialised product. The process has also generated new techniques and patents, including a method for carbohydrate super-digestion in 2011 and a method for producing short aftertaste in 2015.
A Datamonitor case study from May 2009 on the popularity of "low" or "zero" health-conscious marketing in Japan and other countries notes that Japan brought in a new health check for metabolic syndrome in April 2008, aimed at preventing lifestyle diseases such as diabetes. The introduction of the new test also coincided with lots of "healthier" beers being released by major Japanese brewers. New styles of beer and beers with lower malt content are taxed at a lower rate, which can be passed on to the consumer in the form of a less expensive and therefore more competitive product. (Although they're also not legally "beer" in some cases.) Consumers still rate taste as more important than any health benefits, but improved brewing technique has made these new brews taste as good as traditional ones.
However, there is a lot of disagreement on whether these drinks are healthy. They still contain alcohol, which is where the calories are coming from.
I don't have a massive knowledge of labelling/advertising laws in Japan, so I'm not sure if Tōshitsu Zero really has no carbohydrates at all - there may be a limit under which you can call something "zero carb" (implied by the Datamonitor case study) or it may depend on how you define "carbohydrate".
- Original article (Japanese, NicoNico News, 30 July 2018)
- Gekkeikan Tōshitsu Zero product page (Japanese)
- Datamonitor Japanese healthy beer/brews case study (English) Discussion of low-carb sake on page 12.