Poland
Baltic brewers ferment export porter as a lager
Brewers around the Baltic reproduced strong British export stout using bottom fermentation and cold maturation, producing a smoother beer of the same strength.
1820–1900
Why it matters
The clearest example of a style crossing a fermentation boundary and becoming something else, and the reason a porter can be a lager.
How well this is established
| Certainty | Well attested. Broadly agreed across sources, though the precise dating or detail may vary between them. |
|---|---|
| When | 1820–1900. Recorded as a period rather than a date because it happened over time. |
| Where | Poland |
Styles this shaped
Traditions
- Baltic porter brewing — The Baltic adaptation of English export porter, rebuilt with lager yeast and cold fermentation at high strength.
Either side of this
← 1820: Irish brewers adopt unmalted roasted barley · 1830: The Burton union system comes into use →
See the whole sequence on the beer history timeline.
Last reviewed 2026-08-16.