Name one common off-flavor that is a result of fermentation stress.

The off-flavor commonly associated with fermentation stress is nail polish remover, which is primarily caused by the presence of acetaldehyde, a byproduct of yeast metabolism. When yeast is stressed due to factors such as high fermentation temperatures, nutrient deficiencies, or excessive oxygen exposure, it can produce higher levels of acetaldehyde. This compound has a distinct, sharp flavor reminiscent of nail polish remover, which can significantly detract from the overall quality of the beer.

Understanding this off-flavor is crucial for brewers and servers, as it highlights the importance of maintaining optimal fermentation conditions. Proper yeast health and management practices can help minimize the risk of this and other off-flavors during fermentation.