Vague, undefined, contradictory and divisive. Some brewers avoid using it altogether, while still producing delicious, refreshing beers in the lower pH range.

Let’s take a closer look. First, ‘sour’.

Most literally, this covers any beer with a low pH, typically around three or four. Now, while different beers can share similar pH readings, it does not follow that they share much else. They can taste quite different and can be made using unrelated techniques, with distinct ingredients.

That’s why many craft brewers prefer to avoid the term – it isn’t very helpful for the punter. But it does mean the sour beer tribe includes a wide and often unpredictable range of flavours, aromas and drinking experiences.

There was once a time, back before Louis Pasteur discovered the role of yeast, when most beers were sour-ish. Wild yeasts and other bugs tend to produce acidity, and many home brewers (and even some commercial ones) have experienced the unwanted vinegary tang of acetic acid in their handiwork. Today brewers go to great lengths to help their brewing yeasts thrive and keep other bugs out.

Sour brewing is the exception here. Wild yeasts and bacteria are encouraged or even deliberately introduced. Different techniques have different results.

The quick way is to add a souring agent to the beer during fermentation. The most common are Brettanomyces (a yeast), Pediococcus (the bacteria that ferments sauerkraut), and Lactobacillus (yoghurt bacteria). The results are fast and almost predictable.

Slower and less-predictable techniques include chucking some fruit into the beer, and aging a beer in wine barrels. The yeasts already living on the fruit skin and on the barrels cause a second, sour fermentation, and the fruit and wine-soaked barrel wood add to the flavour.

Or brewers can just go for broke, leave the beer exposed to the air and all the greeblies floating around in it, and take their chances. This is the most traditional way to make a sour beer, and probably the oldest way to make any beer. The wort sits naked and exposed in a coolship – like a shallow swimming pool – and whatever lands in it is left to thrive. This is the technique famously used to make the famous Belgian lambics, and many New Zealand brewers now have a coolship or other vessel to catch their own unique biota of greeblies.

And second, ‘beer’.

Yes it’s true that sour beers share the same basic ingredients and equipment as other beers, but, wow, you wouldn’t know it from the flavours.

You know those people, you know who I mean, who tell they don’t like beer and they’ve tried them all?

Well try them on a well-made sour and wait for the denial – ‘That’s very nice but it isn’t beer!’

Most beers balance hop bitterness and malt sweetness – that’s the deal. But sours forgo most or all of the bitterness for acidic sourness, balanced against the malt and fruit sugars. So if you’re seeking the big, fresh hops hit (and believe me, I do!), you won’t get it here. But if you don’t like bitterness, then sours bring an opportunity to revisit what beer can be and what flavour experiences skilled brewers can deliver.

Some sours convey the wine that previously sat in the barrels. Fruit obviously if subtly contributes too. But the sour fermentation adds dimensions all of it’s own, most obviously with Brettanomyces. This yeast gives aromas and flavours often described as ‘farmyard’, ‘wet horse blanket’ (don’t ask me, I was born in Te Aro) and, in a catch-all, ‘funk’.

And of course all these different dimensions change over time, meaning it can pay to cellar and revisit sours beers over a period of years. In fact, with many of these, fresh is not best.

So, as a totally unscientific demonstration of sour beer diversity, here’s the 22-beer SourFest 2019 lineup, all on tap:

From Belgium:

Lindermans Kriek, Belgian Kriek Lambic

Kriek Boon, Belgian Boon Kriek

Duchesse De Bourgogne, Belgian Flanders Red

From the USA:

Lagunitas, Sweet Tart sour mash Ale

From New Zealand:

Blackdog, Mellon Collie

8-Wired, A Fist Full Of Cherries

Te Aro Brewing, Belgian Sour Blonde Ale

North End Brewing, La Voile Noir Dark Saison

North End Brewing, Rivage Brux Barrel Aged Farmhouse Ale

Fork Brewing Mix Six Six, Blended Sour Ale

Craftwork, Terroir Blend 2017

Sawmill, Passionfruit Sour

Garage Project, Raspberry Lemonade Sour

Hallertau, Funkonnay

Deep Creek, Aloha Passionfruit & Guava Sour

Whistling Sisters, Rooty Toot Toot

Moa, Sour Cherries on the handpull

Tuatara, Two-year Aged Raspberry Belgian Sour

Three Boys, Salt & Sour Gose

Juicehead, Kettle Sour Lemon Verbena & Hibiscus

Maiden Brewing, Plum Kettle Sour

Bach Brewing, Raspberry Berliner

Plus more….

Next time we check out Ginhouse Returns – Mothers’ Ruin takes centre stage again! Luke & Anthony from Hidden World Gin are back showcasing their latest release, Hot Cross Bun Gin on tap. There will also be seven brand new G&T matches plus Negroni’s and Gin & Tonic on tap

SourFest 2019 – From Friday 5 April until the sours pucker off

Ginhouse Returns – From Friday 12 April until the gins pucker off

Cheers!

Martin Craig

Guest Malthouse Blogger