
Amontillado sherry is a dry, amber-hued sherry that ages first biologically under flor, then oxidatively, giving it more depth than Fino but less weight than Oloroso.
Sherry is a scale from bone-dry and saline to heavy and nutty, and this one sits in the middle. Moving either way costs you the balance rather than the character: lighter brings salt and freshness, heavier brings weight and less delicacy.
Fino ages under flor its whole life and stays pale, fresh and saline. Amontillado goes oxidative after the flor dies, taking on amber color and nutty depth. Fino keeps a drink crisp and bright; amontillado gives it weight and a dry nut finish.
Oloroso is fortified from the start and aged with no flor stage, which gives it a fuller, heavier body. Amontillado stays lighter and finer. In a stirred drink oloroso reads richer and rounder; amontillado leaves more room for the spirit.
Medium sherry
Amontillado is dry by definition — a sweetened version of the same style is labeled "medium", not amontillado. Pick one up by mistake and the drink comes out noticeably sweeter than the recipe intended.
Oxidizes once opened; more resilient than Fino but still best drunk within a couple of weeks — keep it stoppered and refrigerated.