"Let's move on to the next ingredient in sake: rice!"
Fusako led them into the once-steamy building. She took off her shoes as she stepped up onto the veranda, briefly disappeared inside, the re-appeared wearing tatami sandals, and holding a pair for each of them.
"Please wear these indoors, carry your shoes with you, and try to make way for my coworkers. If we make the floors wet, or block the passageways someone could get hurt."
The interior of the building had two sections separated by a wall of sliding wooden dividers. One of the panels had a black border and an ancient painting of a dragon that was still recognizable despite being very well-worn from decades of daily use.
This panel was pulled aside and the young blonde Yamataian woman and anthro squirrel were carrying buckets full of fluffy-looking rice in from the other room. They completely ignored the group of tourists and each put their buckets on a small platform, then pulled a rope which tugged the platform up to the second level, where a moment later, the platform would return with empty buckets that the two workers would carry back into the other room.
The room in which Fusako and her group now found themselves had a log-sized wooden axle running across it just below the ceiling. The axle turned slowly groaning deeply as it did so, and they could see through the still-open sliding walls to the outside that it was turned by the water wheel. The axle was mounted on both sides of the building in well-greased metal sleeves that seemed to contain bearings so it could spin freely. Just inside from the veranda on the side of the building with the water wheel, a set of metal baskets covered the wall. They sat at an odd angle: almost sideways, but tilted up just enough that they could spin without their contents tumbling out. And indeed, they were spinning furiously, as they were linked to the great wooden axle. At the same time, water was trickling down onto each basket from an extension of the aqueduct they had seen outside. The water seemed to wash over the contents and trickle down into a grate below them.
"Here is where we polish rice. As you may be aware, rice has an outer layer of fats and proteins and an inner layer of nearly pure starch. The koji converts the starch into sugar, which the yeast converts into alcohol. The fats don't incorporate well into sake and can go rancid before too long. But it isn't as simple as polishing away the outer layer, because koji also creates enzymes that break down proteins and these are largely responsible for all the flavour that is possible in sake besides the most basic starch, sugar, and yeast byproducts. It is a delicate balance, and highly dependent on your koji, which can be quite temperamental."
Fusako glanced at Koyama while she mentioned koji, anticipating that the neko would most enjoy the next section of their tour. Then she swept her wide-sleeved arm towards the grates under the rice polishing setup and looked to Taro.
"This is where much of our output water comes from, hence why we would be producing a lot of rice sediment if we didn't filter it. Since we do filter it, we are able to make use of the sediment to make things like rice crackers. It also works well as a protein supplement."
On the floor of the room, there were wooden tubs full of rice, and wooden sticks along one wall away from the rice polishing rig.
"Once we have polished the rice to the desired protein/starch ratio, a process which takes several days, we then soak it."
As if on cue, a male Yamataian worker appeared from the other room. He wore the standard dark blue work uniform that the other workers wore, but instead of a bandana, he wore a cap. A stopwatch dangled around his neck, and he smiled nervously as Fusako gestured to him.
"This is Tumara Ikko, and he is the tōji today, which means that he is in charge. Soaking the rice is such a crucial part of the process, it is up to the tōji to measure how much time the rice has spent soaking and prevent it from absorbing too much, or from being drained too early."
Fusako then led the group into the next room, which was almost entirely occupied by a couple of massive tanks that were only about waist-height, but looking down into them, they were clearly set deep below the floor level. A light mist was still rising from one of them, which had clearly been the source of all the steam earlier when everyone was still arriving. Towering over the misty tank was a Kodian with mostly black fur, but who had a patch of white on their chest that the dark blue uniform didn't quite cover. The Kodian looked at the group with disinterest.
"This is Hitonokuma Kumi, one of my very best kurabito."
While the ceiling in the first room was quite low, the ceiling here was quite high and far above they could see a large opening to allow the steam to escape. Both tanks contained very moist rice, but only the steamy one was warm.
"Once the rice is soaked, we steam the rice here overnight."
As Fusako spoke, her coworkers repeatedly entered the room with empty wooden buckets, handed them to the Kodian, who filled them with steamed rice and handed them back, then disappeared again.
"Do my honoured guests have any questions before we move on to the koji section of the tour?"