Aged English strong ale. Dried fruit, leather, sometimes a hint of acetic edge from wood maturation. Brewed to last; intended to age.
Old Ale was traditionally aged at the brewery in oak vats for months or years before release. The style is intentionally oxidative — the sherry-like, lightly-acetic notes are features, not flaws. Modern versions skip the wood aging but maintain the long-cellar character through high ABV (6-9%) and rich malt bills. Some classic examples (Theakston's Old Peculier, Greene King Strong Suffolk) are blended from young and aged beers before bottling.
Cellar at 55-60°F. The style benefits from rest — drinking too fresh misses the developed character that defines the category. Some bottles improve for 5+ years before reaching peak.
Within 1-2 years for typical examples. 2-4 years for stronger versions; some 9% Old Ales drink beautifully at 7-10 years. The style is forgiving of long aging in a way most beers aren't.
These breweries either specialize in Old Ale or produce notable examples: