How is sake made?
The taste of sake can be best described as complex, especially when dealing with the more premium brands. In many cases, such complexities can only be attributed to a brewing process that has been perfected over the span of many generations.
In this article, we will take a closer look at how sake is made, but before we get into that, we will first uncover what sake is made from.
What is sake made of?
Ingredient quality is one of the things that separates premium brands from the rest, but nevertheless, all types of sake basically use the same ingredients.
Rice is the most important ingredient and without it, sake just wouldn’t be sake. But what most people do not know is that any kind of rice can be used whether white, brown, short grain or long grain. However, this doesn’t mean that all types of rice are equal because a common trait amongst premium brands is the exclusive use of white, short and medium grain Japonica rice.
Koji mold spores
Mold has a bad reputation because it’s an allergen and some species are even downright toxic. Koji mold spores, on the other hand, is perfectly safe and is an essential ingredient as it converts rice starch into sugar.
Most sake breweries use only the highest quality water which is why so many of them are located right next to or very near a mineral enriched fresh water source. The ideal water is rich in potassium, magnesium and phosphoric acid because these minerals play a vital role in assisting the propagation process of the yeast and koji mold.
Yeast is essential for every type of alcoholic drink, but the strain used for making sake is a little different. As a matter of fact, the yeast strain used in making sake has a clear, direct effect on not only the aroma but also the taste of the brew.
Most sake brands add distilled alcohol but this was something that was never practiced before world war 2. Food shortages during the war demanded rice farmers grow rice for food consumption instead of for luxuries like sake. Brewers, as a result of shortages, began adding distilled alcohol to their batches to increase yield.
The war is long over, rice is in abundance once again, yet the habit continues to this day but for different reasons. Whereas before it was added to increase output, today it is added to enhance the flavor.
It’s worth noting that premium sake contains considerably less distilled alcohol than the non-premium brands unless it’s Junmai, which doesn’t use any.
Japanese sake is naturally sweet. Therefore, lactic acid is added to counteract the excessive sweetness. Other benefits include preserving the flavor and killing germs.
How is sake made?
Now that we know what sake is made of, we will see how all these ingredients come together to create the final product.
Preparing the rice
In the first step of making sake, rice has to be prepared. This is done by milling away a certain percentage of each rice granule’s outer layer.
But why do this?
Each rice granule has an inner core which consists of pure starch with an outer layer of protein. The less protein makes its way into the sake, the higher the quality. Not only does it give the sake a smoother taste but it also allows for easier fermentation.
The highest quality sake, Daiginjo, mills up to 50% of their rice granules – which means that each rice granule which goes into the brew is half of its original size. Non-premium brands mill very little, often as little as 10% is removed with the outer 90% still remaining.
How is rice milled?
Rice milling is done by machine because it’s an extremely delicate process and can take up to 2 or 3 days to remove 50% of the outer layer.
When polishing is done, rice gets washed and soaked in water. Once soaked, the rice undergoes a steaming process before being cooled down and spread out onto a table.
Adding Koji Mold
Koji mold spores are added and mixed into the rice. The batch is covered with cloths to keep the temperature consistent and then left for 48 hours while the mold grows.
The purpose of adding koji mold spores is so that the enzymes produced by the mold can transform the rice starch into sugar. And remember how the rice was soaked to absorb water? The reason behind it is so that the mold can grow faster because it needs dampness or a water source to grow.
Fresh spring mineral water and yeast are mixed together into a special container. Earlier I mentioned the importance of the quality of the water used in making sake because up to 80% of every bottle consists of water alone. Yeast strains play just as much of an important role as there are only a handful of strains used by sake manufacturers – depending on the brand.
After this is prepared, the koji rice is carefully added in bits over a period of a couple of days to ensure that the yeast doesn’t get diluted too fast.
This is known as the fermentation process. A process where the yeast turns the sugar into alcohol. Temperatures within the container are very carefully monitored and controlled, and all mixing is done by hand over a 21 day period.
It’s also during this stage that lactic acid and distilled alcohol gets added to the batch.
Once the fermentation process is complete, it’s time for pressing. Pressing is where they extract the liquid from the mash and can be done either by machine or hand.
The mash is poured over cloth bags and the liquid drips through while the mash stays behind. In order to make cloudy sake, a different cloth is used that allows for some of the rice particles to make their way into the liquid. That is how cloudy sake gets its cloudy appearance.
It’s a rather special day at any sake brewery and you will often find employees tasting the batch for the first time. And if you are ever lucky enough to visit a sake brewery on a pressing day, you will be able to taste the batch yourself.
The final stage
Once the sake has been extracted from the mash, it either gets bottled directly or placed into storage to be aged, depending on the brand.