What might happen if the levels of proteases are too high in Kōji?

The correct answer highlights that excessively high levels of proteases in Kōji can lead to overly elevated umami levels. Kōji, which is made from steamed rice inoculated with mold (usually Aspergillus oryzae), is essential for the fermentation process in sake production. Proteases are enzymes that break down proteins into amino acids, including glutamic acid, which is a key component contributing to umami flavor.

When protease levels are optimally balanced, they enhance the flavor profile of the sake, providing a desirable umami richness. However, if those levels become too high, the breakdown of proteins can produce an excess of free amino acids, particularly glutamate. This can result in an unbalanced flavor that may overwhelm the sake with excessive umami, potentially overshadowing other flavors and diminishing the overall complexity of the final product.

The other choices present options that do not directly relate to the role of proteases in Kōji. Alcohol production is primarily influenced by amylase enzymes that convert starches to sugars, not directly by protease levels. While sugar breakdown could theoretically be impacted by other enzymatic activity, it is not a primary consequence of high protease levels. Yeast reproduction could be negatively affected by various factors