Fermentation: the biochemical process by which microorganisms (e.g., yeast, bacteria) break down sugars to produce alcohol, acids, gases, etc.; commonly used for food and beverage production.
パン生地を室温で発酵させるとふっくら膨らむ。
If you ferment bread dough at room temperature, it will swell up nicely.
ヨーグルトは牛乳を乳酸菌で発酵させて作る。
Yogurt is made by fermenting milk with lactic acid bacteria.
酒造りでは酵母による発酵の管理が重要だ。
In sake brewing, controlling yeast fermentation is important.