Which Sherry style tends to have the highest alcohol content?

The style of Sherry that tends to have the highest alcohol content is Oloroso. This is primarily due to the production process involved in making Oloroso Sherry. Unlike Fino and Manzanilla, which are biologically aged under a layer of flor yeast that limits the alcohol content, Oloroso is intentionally oxidatively aged.

During this aging process, Oloroso Sherry undergoes a higher degree of evaporation, which concentrates the flavors and results in a naturally higher alcohol content. The initial fortification of the base wine for Oloroso typically occurs to a higher alcohol level, usually around 18% to 20% alcohol by volume. This contrasts with produce styles like Fino and Manzanilla, which have lower final alcohol levels, often around 15% to 17%, due to the protective flor yeast that develops during their aging.

Amontillado, while also higher in alcohol than Fino and Manzanilla, does not reach the alcohol concentration level of Oloroso due to its unique aging process, which begins under flor before being subjected to oxidative aging. Thus, Oloroso stands out for its higher alcohol content, resulting from both the fortification process and the type of aging it undergoes