Edited by Aj
There’s a moment, usually at a craft beer bar with a long tap list and a slightly overwhelming chalkboard, when you pick something called a “passion fruit Berliner” because the description sounds interesting and then you take a sip and think: wait, is this meant to taste like that? Yes. It is. Sour beer is supposed to taste sharp, tart, sometimes a little funky, and nothing like the lager you grew up with. That’s entirely the point.
Sour beer is one of the most exciting corners of the beer & cider world, and also one of the most misunderstood. People assume they won’t like it before they’ve tried the right one. But the category spans everything from delicate, lightly tart wheat beers to deep, wine-barrel-aged wild ales that take years to make. There’s a lot of ground here. Spiritly is here to help you find your footing.
In One Sentence
Sour beer is beer that has been intentionally made tart or acidic, either by introducing wild bacteria during fermentation or by using fast-acidification techniques, resulting in flavours that range from gentle lemon-zest brightness to complex, vinous depth.
A Style as Old as Beer Itself
Before brewers understood the science of fermentation, all beer was essentially sour. Wild yeast and bacteria drifted in from the air and did whatever they liked. Most of it was probably variable and strange. But in certain regions, particularly Belgium and northern Germany, brewers learned to work with that wildness rather than against it.
Belgium’s lambic tradition, centred around the Senne valley near Brussels, is the oldest continuous example. Lambic brewers leave their wort (the liquid extracted from malted grain before fermentation begins) exposed to open air overnight, letting naturally occurring wild yeast and bacteria settle in. The result ferments slowly, sometimes for years. Germany developed its own lighter, faster styles: the Berliner weisse, a low-alcohol wheat beer with a clean, sharp acidity, was popular in Berlin by the nineteenth century.
For much of the twentieth century, sour beer largely disappeared from mainstream brewing. Modern brewing technology made it easy to eliminate the bacteria that cause sourness, and most drinkers weren’t asking for tart lagers. Then the craft beer movement changed the conversation. By the 2000s, American and eventually New Zealand brewers were actively seeking out sourness, experimenting with bacteria in controlled environments and drawing on both Belgian and German traditions to build something new.
How the Tartness Actually Gets In There
There are two main routes to a sour beer, and they produce quite different results.
The traditional method is wild or mixed fermentation. The brewer either exposes the wort to open air (as Belgian lambic producers do) or deliberately adds wild strains of yeast and bacteria, most commonly Lactobacillus and Pediococcus (lactic acid-producing bacteria) alongside wild yeast like Brettanomyces. These microorganisms work unpredictably and slowly. The beer often matures in old wine or spirit barrels for months or years. The result is complex, layered, and genuinely one-of-a-kind.
The modern method is kettle souring. The brewer adds Lactobacillus bacteria directly to the wort before the main fermentation begins, holds it at a warm temperature for a day or two until the desired acidity is reached, then boils it to stop the bacteria and proceeds with a normal yeast fermentation. It’s faster, more predictable, and more affordable to produce. Most of the fruited sours and Berliner weisses you’ll find on a New Zealand tap list today are made this way.
Neither method is better. They just make different kinds of beer.
Styles Worth Knowing
Berliner Weisse
A low-alcohol German wheat beer with a clean, bright sourness. Think lemon juice over fizzy water. Light-bodied and refreshing. Very easy to drink. Often served with fruit syrup in Germany, though craft versions tend to skip the syrup and add real fruit instead.
Gose (pronounced go-zuh)
Also German in origin, from the town of Goslar. A wheat beer brewed with salt and coriander seed. The salt doesn’t make it taste salty so much as it rounds out the acidity and adds a certain savouriness that works extremely well with added citrus or tropical fruit.
Fruited Sour
This is the style that pulled most New Zealand drinkers into the category. Usually a kettle-soured base, often Berliner or Gose, loaded with fruit purée or juice. Passion fruit, mango, raspberry, guava, feijoa. The fruit and the acidity hit at the same time, and the effect is something between a beer and a very dry fruit juice. Bright, vivid, and genuinely fun.
Lambic and Gueuze
Belgium’s wildest tradition. Lambic is the base beer, made by spontaneous fermentation. Gueuze (pronounced roughly like “gur-zuh”) is a blend of young and old lambics, bottle-conditioned until it develops a champagne-like fizz and extraordinary complexity. Earthy, barnyard-y, funky, and dry. An acquired taste, but an unforgettable one.
Flanders Red and Oud Bruin
Belgian styles with a deeper, maltier character. Flanders red ales ferment in large wooden vessels and develop a complex sweet-sour balance, almost like a tart cherry vinegar crossed with red wine. Oud Bruin (meaning “old brown”) is darker and slightly sweeter. Both reward patience and a slow sip.
Five Sour Beers Worth Starting With
- Garage Project White Mischief (Wellington): A kettle-soured wheat beer, lightly salted and infused with white peaches. Tart, juicy, and refreshing. A perfect entry point.
- Sawmill Passionfruit Sour (Matakana): Bright, tart and loaded with passionfruit.
- Yeastie Boys Gunnamatta Earl Grey IPA: Not a sour, but if you enjoy the brightness of a sour, this tea-infused beer has a similar clarity of flavour and is made by a proudly NZ-founded brewery.
- Cantillon Gueuze (Belgium): The benchmark. Funky, bone dry, and complex. Don’t expect to love it on the first sip, but do try it at least once.
- Lindemans Framboise (Belgium): A lambic blended with raspberry. Much sweeter than a traditional gueuze, which makes it an accessible gateway into the wild fermentation world.
Frequently Asked Questions
Is sour beer actually good, or is it just a trend?
It’s been around for centuries, so probably not just a trend. The fruited sour craze might ebb and flow, but wild and mixed fermentation beers have a permanent place in serious brewing culture. Whether you personally enjoy them is a different question, and the only way to find out is to try a few different styles.
Why does some sour beer taste funky or barnyard-y?
That comes from Brettanomyces, a wild yeast often called “Brett” by brewers. It produces compounds that smell and taste like leather, earth, hay, or even a hint of bandage (in a way that some people find compelling). It’s a natural part of traditional Belgian fermentation and is considered a feature, not a flaw.
Is sour beer lower in alcohol?
Some styles are, particularly Berliner weisse, which is often under 4% ABV. But many sour beers are full strength or higher, especially barrel-aged wild ales. Check the label rather than assuming.
Can I use sour beer in cooking or with food?
Absolutely. The acidity in sour beer works the same way as a squeeze of lemon or a splash of vinegar. A gose pairs well with shellfish and light seafood. A Flanders red cuts through rich, braised meat beautifully. For more ideas on matching drinks with food, the food & drink section has plenty to explore.
