Reigen Fermentation

Reigen is a Berlin-based sake brewery located in the basement of a former bowling alley. The old Keglerklause was renovated in 2022 together with our neighbors Aru, Ernst Cave, and Julius. Since 2024, Reigen has operated here as an open manufactory, dedicated to brewing high-quality European sake.

Our focus: sake brewed using the traditional Bodai-Moto method. This ancient fermentation technique creates especially complex and layered flavors — bolder and funkier than conventional sake. The result: handcrafted premium products that appeal to both sake enthusiasts and wine lovers alike.

Beyond sake, our range includes sake kasu and amazake. Kasu — the flavorful rice lees left after pressing — is perfect for seasoning, pickling, or as a natural bread starter. Amazake is a non-alcoholic rice drink: mildly sweet, full-bodied, perfect on its own or served as a dessert.

We carefully select our ingredients — and handle them with precision and care.

Every batch of our sake starts with rice from De Tacchi, a family-run farm in Northern Italy with a tradition going back centuries.
Instead of importing highly polished sake rice from Japan, we use risotto rice with a low polishing rate. This preserves more of the original grain, resulting in a fuller, more intense flavor — and significantly reduces transport emissions.

Another key component is our in-house koji production.
The steamed rice is inoculated with koji spores and cultivated over two to three days under carefully monitored conditions. This step is essential to developing the depth and complexity that define our sake.

Just as important: the water.
We brew with filtered Berlin tap water — clean, mineral-rich, and deeply connected to the place where our sake is made.

Fermentation doesn’t happen by chance. It’s driven by precision — and a deep understanding of the many small details that shape the final product. Every step in our process matters, from the first rinse to the final press.

1. We begin by thoroughly washing the rice to remove excess starch. It's then steamed — the ideal preparation for both Koji cultivation and the brewing process.

2. This is where the "magic mold" comes in: Aspergillus oryzae is inoculated onto the warm rice. Over the next two to three days, the rice develops both complex aromas and the enzymes needed to convert starch into sugar — the essential foundation for fermentation.

3. All ingredients are then mixed together. The main fermentation begins — a slow, carefully monitored process during which sugar transforms into alcohol and the flavors evolve layer by layer.

4. Optional: For our sparkling varieties, a small amount of rice, koji, and water is added just before pressing. This provides the extra sugar needed for a second fermentation in the bottle — similar to the Pet-Nat method in natural winemaking.

5. Once fermentation is complete, the mash (traditionally called "moromi") is gently pressed using our custom-made traditional-style fune press: precise, gentle, and efficient.

6. The sake is then matured at room temperature. Some batches undergo light oxidation in tanks, others are bottled fresh. In most cases, we keep our sake "nama" (unpasteurized) for maximum flavor. Alternatively, we gently pasteurize selected batches to increase shelf stability and aging potential. We never use preservatives.