Kura-tsuki Kin (House Microbes)

In the beams, walls, and wood grain of old breweries, microorganisms unique to each facility have taken up residence—these are kura-tsuki kin. Through decades or centuries of continuous brewing, a selected microbial community settles in, producing flavors replicable nowhere else. This is why flavor can change when a brewery relocates. House microbes are invisible artisans. The building itself is fermentation infrastructure—an irreplaceable asset nurtured over time. Recently, alongside the wooden vat revival movement, interest in house microbes has grown. The symbiosis between wood and microbes, irreproducible in stainless tanks, draws attention. House microbes embody the principle that flavor resides in place.