However, the sake that stands out most in my opinion is the aformentioned Spontaneous Fermentation (自然仕込 ) series which hark back to more tradition methods of brewing by using no cultured yeasts. Instead, these ultra-rare brews are made by the yamahai method (see Beyond the Basics) and rely on the natural yeasts present in the nooks and crannies of the kura to carry out the complex process of fermentation. The most extreme version of this is the Junmai Yamahai White Label that is produced every year around February. As Harper pointed out during my visit, the house yeast is certainly a lively one, and every year it results in a final alcohol content of over 20% abv. I was lucky enough to try this year's version recently, which came in at a whopping 22%. Definitely not for the faint hearted! 

To try and summarise what makes Tamagawa so appealing, and therefore one of my favourite breweries, I would say that through its intricate product line-up, it manages to appeal to sake enthusiasts who value the back-story of how they were made just as much as the enjoyment that comes from drinking them. To consider how much of the process has been entrusted in the hands of mother nature not only speaks volumes for how confident Harper is in his abilities, but also of the importance of having all of the elements working together in harmony.

To me at least, these types of sake are always that little bit more interesting and complex. Indeed, I have never felt so excited and spoiled for choice than I was when I visited the brewery store after my tour of the kura. Thankfully, the company president has stated that although demand for Tamagawa has increased rapidly over the last decade, they remain committed to producing sake with "soul". I for one look forward to enjoying these soulful beverages for many more years to come.