Final answer:
Fino Sherry has higher levels of acetaldehyde and acidity, contributing to its sharp taste, while Oloroso Sherry, which undergoes direct oxidation, has lower acetaldehyde, a richer flavor, and often higher alcohol content.
Step-by-step explanation:
When comparing Fino Sherry to Oloroso Sherry, there are distinct differences in their composition regarding alcohol, acid, and acetaldehyde levels. Fino Sherry typically has higher levels of acetaldehyde, which contributes to its distinctive, yeasty aroma and sharper taste profile due to its production under a layer of flor yeast that inhibits oxidation and preserves acetaldehyde. In contrast, Oloroso Sherry does not develop under flor and undergoes direct oxidation, which results in lower amounts of acetaldehyde but leads to a richer, stronger flavor, and often a higher alcohol content. Additionally, Fino Sherry will have a noticeably higher level of acidity in comparison to the fuller-bodied Oloroso Sherry, which tends to have a softer acid profile.