Sour Beer
Scotland's most exciting modern beer category — led by one of the world's best sour breweries
Sour beer is produced by deliberately introducing acid-producing bacteria (Lactobacillus, Pediococcus) or wild yeasts (Brettanomyces) into the fermentation, creating beers that are tart, fruity, and often intensely aromatic. Scotland has a standout presence in the global sour beer scene: Vault City Brewing in Edinburgh is widely considered one of the best sour beer producers in the world, with their fruit-forward pastry sours appearing on international 'best beers' lists. Scottish sours range from refreshing session sours at 3.5% ABV to boozy imperial sours pushing 10%.
What does Sour taste like?
Tart, acidic, fruit-forward, refreshing, often intensely aromatic
Scottish sours split into: Kettle Sour (quick acid addition, sessionable, most common), Pastry Sour (heavily fruited, sweet-meets-tart, often higher ABV), and Imperial Sour (high alcohol, intense fruit). Vault City primarily produces Pastry and Imperial Sours — intensely fruited, dessert-like beers that sit at the extreme end of the style.
Those who like sour/tart flavours; wine drinkers exploring beer; warm weather; dessert pairing
Those who dislike sour or acidic flavours; anyone looking for traditional ale character
Best Scottish Sour
Strawberries & Cream
Vault City Brewing
Edinburgh
Vault City's signature pastry sour — the beer that put Edinburgh's sour scene on the world map
Brewery profile →Black Forest Cherry
Vault City Brewing
Edinburgh
Imperial sour — rich, intense, and deliberately dessert-like
Brewery profile →Session Sour
Vault City Brewing
Edinburgh
Vault City's rotating lower-ABV fruit sour — different fruit each release, always excellent
Brewery profile →Background
Sour beer traditions are ancient — wild fermentation and acidification predate controlled brewing. Belgian lambic and gueuze are the classic European references. The modern kettle sour method (fast, controlled acidification) was developed by US craft brewers in the 2010s and democratised sour production. In Scotland, Vault City Brewing (founded 2018) became the country's specialist sour producer and grew rapidly to international recognition.
How to serve Sour
6–9°C — serve cold to emphasise the refreshing tartness
Tulip or white wine glass — the shape concentrates the fruit aromas
From pale yellow (kettle sours) to deep purple/red (fruit imperial sours)
Food pairings
Key facts
- ✓Vault City Brewing in Edinburgh is widely considered one of the world's best sour beer producers
- ✓Scottish sour beer barely existed before 2015 — it's entirely a craft era phenomenon
- ✓Pastry sours are among the most divisive beers in the craft scene — intensely sweet, fruited, and often over 7% ABV
- ✓The kettle sour process can produce a finished sour beer in 3–5 days, versus months for traditional lambic
Frequently asked questions
Is sour beer supposed to taste like that?
Yes — the sourness is intentional, not a fault. Sour beers are deliberately made tart by introducing acid-producing bacteria during fermentation. If it's labelled sour, the tartness is the point. It's an acquired taste but most people who try quality sour beer find they enjoy it more than expected.
What is Vault City Brewing?
Vault City Brewing is an Edinburgh sour beer specialist founded in 2018. They produce fruit-forward pastry and imperial sours and are considered one of the world's best sour beer producers — unusual for a brewery less than 10 years old. Their beers appear regularly on international 'best beers' lists.
What is the difference between a Kettle Sour and a Pastry Sour?
Kettle sour is acidified during the brewing process (quick, controlled, sessionable result). Pastry sour is heavily loaded with fruit additions after fermentation, producing intensely sweet-tart beers that resemble dessert. Pastry sours are usually higher ABV and significantly sweeter than kettle sours.