Zaku’s Prototype series is a very interesting, sparkling offshoot of their normal brand which for some reason does not make an appearance on their website.
The carbonation is not at all like a champagne or sparkling water, but instead is very subtle. I would not go so far as to call this “sparkling,” despite the multiple CO2 warnings on the label.
The taste is subtle and fruity, which is very impressive for a genshu sake, as they tend to be very aggressive. This one feels like it has more in common with light, welcoming labels like Dassai than powerful genshu labels like Narutotai.
Zaku continues to impress with their Prototype series and you would be well served to try a glass if you have the opportunity