Moromi

Moromi is a crucial intermediate product in the process of sake brewing. It is a thick, fermented mash that is produced during the main fermentation stage of sake production. The moromi stage is where the majority of the alcohol content is produced, and it is also where the sake's flavor profile is largely determined.

Process

The moromi stage begins after the shubo (yeast starter) stage. The shubo is mixed with additional rice, water, and koji (rice cultivated with a mold called Aspergillus oryzae) in three separate additions over four days. This process is known as sandan-shikomi. The mixture is then allowed to ferment for 18 to 32 days, during which time it becomes moromi.

During the moromi stage, the koji enzymes break down the starches in the rice into sugars, and the yeast converts these sugars into alcohol. This process is known as multiple parallel fermentation, a unique feature of sake production. The temperature and humidity of the moromi are carefully controlled to ensure optimal fermentation conditions.

Characteristics

Moromi is characterized by its thick, chunky texture and its strong, sweet-sour aroma. The taste of the moromi at different stages of fermentation can give an indication of the final sake's flavor profile. For example, a sweeter moromi may result in a sweeter sake, while a more acidic moromi may produce a drier sake.

Pressing

After the moromi stage, the mash is pressed to separate the liquid sake from the rice solids. This process is known as joso. The liquid sake is then filtered, pasteurized, and aged before it is ready to be bottled and sold.

See also

• Sake production
• Rice wine
• Fermentation (food)