What are the consequences of exceeding 14 percent alcohol content during fermentation, and why is it essential to prevent air from entering the fermentation mixture?

Exceeding 14 percent alcohol content during fermentation can lead to incomplete fermentation or stress on yeast cells, causing the production of off-flavors and incomplete conversion of sugars to alcohol. This can result in a suboptimal product with undesirable taste and quality. Preventing air from entering the fermentation mixture is essential to avoid oxidation. Oxygen exposure can lead to the formation of acetic acid and other undesirable compounds, causing off-flavors and spoilage. Airtight conditions maintain anaerobic fermentation, ensuring the production of high-quality alcoholic beverages with the desired alcohol content and flavor profile.