How is Sake made and what is fermentation?
We’re traveling back to 19th century Japan to give you a taste of the hard and time-consuming sake-making process, because it’s always good to take a step back to see where we’ve come to understand and appreciate how far we’ve come. Fermentation involves the metabolic process where sugars are converted into acid or alcohol, using bacteria or yeast. This transformation concentrates all the conditioning elements of rice and breaks down large molecules, which makes it easier for your skin to absorb.
Step one: Washing and soaking When the rice first arrived (remember this is 19th century practices), the first stage was to wash the rice by foot in large tubs called Fumioke. The washed rice was transferred to Kakimasu, a large wooden tub, where it was soaked for a certain period of time. Soaking would help heat penetrate the rice during the steaming process and also speed up the rate at which starch is converted to glucose.
Step two: Piping hot After steaming in Koshiki for 50-60 minutes, the rice continues its journey to become sake.
Step Three: Add Koji Mold The rice is allowed to cool from the steaming process and mixed with Koji (mold) in wooden trays aptly called Kojibuta. Koji mold’s scientific name is Aspergillus Oryzae and it is critical to the sake making process. This addition creates enzymes that break down the starch in the rice and turn it into sugar. As the Koji mold grows, the process generates heat. To control the temperature inside the rice, workers make sure to rotate from top to bottom to maintain the ideal temperature. This fermentation process may seem similar to most alcohol production processes, but the use of koji mold is actually unique to making sake. Without this unassuming addition, sake production would not be possible.
Step Four: Create a startup Koji rice and water are then mixed together to form a puree. Yamaoroshi. The two ingredients are mixed together until they reach an optimal paste-like texture. The mash is transferred to the Dankidaru, which is a sealed vat of hot water, to keep the mixture warm, aiding in the fermentation process.
Step Five: Final Construction Stir, stir and stir some more is this stage of the sake making process. Swirling and stirring the pulp helps further speed up the brewing process. This final stage is also where more rice and water is added to the final mash and when the mash reaches the ideal alcohol and fermentation point, it is removed to be filtered.
Step Six: Clicking and filtering Moromi (mash) is poured into heavy, long cotton sacks to be pressed into the Sakafune, meaning ‘sake boat’. Filtered sake is called raw sake or new sake.
Step Seven: Pasteurization After sitting for about 10 days, the sake is then moved to be pasteurized between 65-70 degrees Celsius.
Step Eight: Aging and bottling The final liquid is bottled in an airtight container and set aside for aging.