What is generally tested during fermentation for quality control?

During the fermentation process of sake production, several key factors are monitored to ensure the quality of the sake. The correct choice focuses on specific measurements that are critical indicators of fermentation performance and overall product quality.

Acidity plays a vital role in the flavor profile of sake and also affects the stability of the final product. Nihonshodo, which is the measure of the specific gravity of the sake, provides insights into the sugar content remaining after fermentation, which is essential for determining alcohol levels and overall sweetness. Alcohol levels themselves are crucial for understanding the efficiency of the fermentation and the balance of flavors in the sake. Additionally, temperature control is imperative, as it influences yeast activity and fermentation speed, and can lead to optimal flavor development or undesirable off-flavors if not maintained properly.

The other options include important factors, but they either lack the specificity needed for quality control during fermentation or mix elements that are typically evaluated at different stages of sake production. For instance, gravity is relevant, but it is encompassed in the measurement of nihonshodo in the correct answer, and while clarity and flavor are essential, they are assessed more as part of the final tasting rather than as part of the fermentation monitoring. Thus, the combination of acidity, nihonshodo