The craft beer revolution continues to gain new adherents every day, with adventurous brewmasters reviving lost styles and looking for inspiration throughout history.
One example is the recent explosion in popularity of sour beers, which are relatively new to North America.
For those not familiar with the style, sour beers have an intentionally acidic or sour taste due to the introduction of certain yeasts or bacterial cultures during the fermentation process.
My first exposure to sour beers was back in 2013, while vacationing in Belgium, also known as the beeriest place on earth, with over 500 distinct beer styles calling Belgium home, most of which are entirely unfamiliar in North America.
Lambics are perhaps the most common sour beer style from Belgium, produced along a 100km stretch of the Senne Valley, with the eponymous River Senne flowing through the center of Brussels, making it an important transportation route in centuries past.
Lambic beers are fermented with naturally occurring airborne yeasts, so may differ from batch to batch. The particular airborne yeast strain used to ferment Lambic beers is called Bretanomyces Bruxenellensis, and occurs naturally only in the Senne Valley near Brussels, making this a highly regional beer style.
The taste of Lambic beer can be off-putting to the novice beer drinker, particularly those raised on a steady diet of Coors Lite. While the wild airborne yeasts can make the taste vary widely from one batch to the next, the primary flavour of a Lambic is one of sour fruit and spice.
To make the sour taste more palatable, the beer will be aged, then blended in equal parts from barrels aged for one, two, and three years prior to bottling.
The youngest barrel in the blend will still contain live yeast, so a secondary fermentation occurs in the bottle, which provides extra depth and complexity, leading to flavours of rich dried fruit.
While Lambics have been exported the world over, with many examples available here in Alberta, the limited region that the yeast is available can make Lambics hard to find.
Calgary’s own Big Rock Brewery built a heavily sealed quarantine room in its brewery back in 2016, in order to produce their own Lambic-style beer without the wild airborne yeasts contaminating their other brews. After aging in oak barrels for two years, a limited release of 3000 bottles of the Big Rock Lambic Style Kriek was released in February of this year, which sold out almost immediately.
I was lucky enough to have gotten onto the pre-order list, so enjoyed the brew on release day, although the whopping $19 price for a 650mL bottle did come with a bit of sticker shock. Made with Belgian candi sugar and Canadian cherries from the Okanagan Valley, it was nicely balanced between sweet and sour, although probably better enjoyed in the heat of summer than in gloomy February. Hopefully there will be another release this coming February!
Berliner Weisse is another popular style of sour beer, first created in the 16th century by adding lactic acid bacteria to a German Wheat beer. Berliner Weisse was once the most popular beer style in Berlin, but started fading into obscurity in the 19th century, until being revived by the craft beer revolution near the turn of the new millenium, with many examples now available where craft beer fans tend to gather.
Here in Alberta, it seems that every new craft brewer is experimenting with a sour beer style, with Gose being a popular choice. The Gose beer style comes from the German city of Goslar, and is unique due to the addition of coriander and salt during the brewing process. The sour characteristics are achieved by adding lactobacillus bacteria after the boil, which interacts with the yeast to produce the desired sour flavours.
Calgary’s own Wild Rose Brewing was the first to bring the Gose beer style to Alberta in 2013, and has been producing a seasonal batch of sour beer every year since. For the past two summers, the Wild Rose Ponderosa Gose has been a popular summer seasonal, bursting with citrus and tropical fruits, with the coriander and salt balancing the tartness to make a refreshing patio beer. This beer is only available in the summer months, so keep your eyes open for a new batch when the snow starts to melt.