Breweries: O
Breweries from Ireland, the Czech Republic and beyond, A to Z, each with the beer styles it brews.

Obolon
Obolon, Kyiv: the brewery built for the 1980 Moscow Olympics, the first company privatised in independent Ukraine and still Ukrainian-owned.

Okocim
1 styleOkocim, Brzesko: the Goetz family's brewery of 1845, once the largest on Polish soil, now Carlsberg's; maker of a classic Baltic porter.
Ölgerðin Egill Skallagrímsson
2 stylesÖlgerðin, Reykjavík: Iceland's oldest brewery, founded in 1913, which brewed through 74 years of beer prohibition.
Olvi
Olvi, Iisalmi: the Finnish brewery founded in 1878, the only one of its era to survive as an independent Finnish company.
Omnipollo
1 styleOmnipollo, Stockholm: a brewer and an artist's partnership, known abroad for its can art and Nebuchadnezzar double IPA.
Opillia
Opillia, Ternopil: a brewery of 1851 rebuilt around unpasteurised beer and kvass, now sold in Poland, Sweden, Czechia and Spain.
Orval
Orval: the Trappist brewery of Orval abbey, set up in 1931 with lay brewers to pay for rebuilding the abbey; one beer, refermented with Brettanomyces.

Ottakringer
1 styleOttakringer, Vienna: the city's brewery since 1837, back in Austrian hands since 2009, maker of a classic Vienna lager.