Final answer:
Fino Sherries form a layer of yeast called flor, which does not form in Oloroso Sherry. This results in a lighter, drier style of wine in Fino Sherries compared to Oloroso Sherries.
Step-by-step explanation:
In the wine making process, Fino Sherries form a layer of yeast called flor, which does not form in Oloroso Sherry. Flor is a layer of yeast that develops on the surface of the wine and protects it from oxidation. This results in a lighter, drier style of wine in Fino Sherries compared to Oloroso Sherries, which are darker and have a richer flavor due to their exposure to oxygen.