What defines an Amontillado sherry?

Amontillado sherry is characterized by its unique aging process, which begins with the protection of flor yeast and then transitions to oxidative aging. Initially, Amontillado sherry starts as a fino, which means it is pale and protected from oxidation by a layer of flor yeast. This yeast forms on the surface of the wine, consuming oxygen and contributing to the wine's fresh, fruity, and briny characteristics.

As the wine ages, it can sometimes lose its flor due to various factors such as environmental conditions or the depletion of nutrients. Once the flor is gone, the wine is exposed to oxygen, leading to a shift in its profile. This oxidative aging results in deeper colors and complex flavors, including nutty, caramel, and rich toasty notes, distinguishing it from other types of sherry.

The other options do not accurately encapsulate the characteristics of Amontillado. For instance, while it is indeed a dry sherry, the mention of blended sweeter varieties or fortification before fermentation does not apply to Amontillado, which is defined by its specific aging process.