Koji rice

Koji rice

It is said that the most important aspect of making sake is the koji. If you can’t make good koji, you can’t make good sake.  What makes good koji you ask? In general, good koji rice has all grains completely covered in koji, and the koji hyphae penetrate deep into the grain (it is the enzymes secreted by the hyphal tips (the ends of the mold cells) that lead to saccharification).  The whole process takes about 48 hours, and for the final half of the time, the koji rice is cultivated in special cedar “boxes” seen in the above photo.  In the box, the koji rice is about 8-10 cm in thickness, and is covered with several blankets to keep in the heat and moisture.  The temperature is very important in the process and will dictate the quality of the koji. The koji spores are sprinkled on the rice when the rice temp is around 32-33C, and throughout the process, the temp gradually rises until approx 42-43C when the growth is complete. It is somewhat difficult to see in the above photo, but there is a remote thermometer monitoring one of the boxes- as the temp rises, the koji rice is gradually thinned by moving a board further along the slots that are visible inside the box.

One of my favorite tasks is the process called ‘de-koji’ (出麹), which literally translates to ‘leaving koji’, as this is the time when the koji is taken out of the boxes, moved to a different room with an air temp of around 12C (as opposed to 32C in the koji room), and spread out on a large sheet.  One reason I like dekoji is because now in Nagano it is freezing cold (today was -12C), and entering into a 32C room is feels like a mini tropical vacation. The other reason is that this is the time when the koji can be evaluated- does it taste sweet? does it have the proper smell (good koji gives off a chestnut smell)? are all the grains covered? not too dry? Good koji also makes a nice snack.

Well, that is a little bit of info about koji. thanks for reading.

Pasteurization(火入れ) and Suda-san

Yesterday, we bottled a new batch of sake, a Junmai-shu, and while some of  will be sold as nama (unpasteurized), some of the bottles were destined for pasteurization and storage over the summer to mature. Today, Suda-san (in the photo) and I therefore set about the task of pasteurizing about 350 bottles (1.8L) of sake which involves heating up the sake to 65C for about 15 min using hot water.

Pasteurizing sake for peace

As you can see from Suda-san’s expression, placing and removing fairly heavy 8-bottle cartons of sake  in and out of hot water is quite fun. The other method used to pasteurize sake here involves running the sake through coiled tubing in a large tank containing hot water, which is then bottled.  For higher quality sake, bottles are heated individually, for regular sake, it’s the tube.  And that’s the story of pasteurization at the brewery.

Happy (belated) New Year.

It is the Year of the Tiger, which just so happens to be my year, so it is perhaps a good omen that our second batch of the year, a Junmai Ginjo,  had a Tiger on the label:

The Year of the Tiger label

It was bottled about 3 days after pressing, and was unpasteurized, so it is Nama (as indicated by the white Chinese character 生 on the black sticker above the label).

It is now a very busy time at the brewery, and we are steaming rice every morning. It is also very cold at 5.30am when I wake up,  and getting out of the warm bed takes a special determination on my part. Homes in Japan generally do not have central heating, so I can see my breath in the morning, it is that cold.

Anyway, I will try and be more diligent with my posts this Year (not off to good start, as it is already Jan.10th), and I hope everyone has a great year of the tiger.