cask
Oloroso
Defined in law
A style of sherry fortified early to around 17% ABV so the flor yeast cannot survive, and therefore aged oxidatively. Casks seasoned with it contribute dried fruit, walnut, leather and colour.
Where it is defined
Sherry itself is protected under the DO Jerez-Xérès-Sherry specification. No whisky regulation defines what an 'Oloroso cask' is.
Worth knowing
Most 'Oloroso casks' filled today are seasoning casks made to order for the whisky industry — new oak charged with Oloroso-style wine for months or a couple of years — not casks that spent decades in a bodega. Since 1986 Spanish law has required sherry to be bottled in the region, which ended the flow of genuine ex-transport butts.
Related terms
Last reviewed 2026-07-30 · All glossary terms