If we were to do a survey among beer drinkers and non beer drinkers about what the characteristic attribute of beer is, its bitterness would surely be the most common answer, way above anything else such as its golden colour, carbonation or even the frothy head.
This predictable answer by the overwhelming majority paints a picture that is actually a far cry from reality, thanks to the endless number of combinations of the 4 basic ingredients in beer, namely: water, cereal malt, hops and yeast, through which we are able to achieve a wide range of different attributes and styles.
This is precisely the case of sour beer, a wide family whose common denominator is acidity or sourness as its most characteristic trait, leaving bitterness in a secondary role.
Acidic, sour or tart beer obtains its characteristic flavour from action by micro-organisms other than the lager and ale yeasts which define most other styles. Those micro-organisms can be bacteria such as lactobacillus and pediococcus bacteria, but also other strains of wild yeasts of the brettanomyces family. Centuries ago, those micro-organisms played a much more prominent role in brewing than they do today, but with the gradual introduction of hops with their bacterial inhibiting power, the sensory scale tipped in favour of bitterness rather than sourness.
Traditional sour beers only remained behind in some regions, mainly in Belgium, until craft beer started to see a growing number of small brewers around the world bold enough to re-explore that sensory alternative, thereby bringing us a wider choice of available brewing styles. Among the classical sour beers and the newer ones, our attention is brought to the following:
- Lambic > The authentic eminence of the sour beer world. Their beers are fermented spontaneously by exposing the must to wild yeast and bacteria of the brettanomyces family that are found in the atmosphere. Their sourness makes them slightly too tart for many palates, and therefore several more “palate-friendly” varieties based on combining younger beers with other aged beers, adding fruit such as cherries or sugar to the end result have appeared over the years (Gueuze, Kriek and Faro styles respectively).
- Oud Bruin and Flanders Red Ale > The combination of lactobacillus and ageing in wood confer these two Belgian varieties the sourness to set off the sweetness of the malt. As is the case in all sour beer, hops only play a residual role, otherwise the bitterness and acidity could be enhanced resulting in a rather unpleasant taste.
- Berliner Weisse > One of the few traditional sour beers brewed outside Belgium. This whitish cloudy beer was very popular in Berlin in the 19th century, where it was sometimes mixed with fruit syrup to set off its strong sourness. It is brewed using ale type yeast combined with lactobacillus.
Sour craft beer > We could include all sour beers that have sprung up over recent decades in this section. Inspired by the classic sour beers, these modern ones freely combine the micro-organisms that are responsible for the acidity with ale type yeast, but also fruit, spices and grain types other than the standard barley, roasted to a higher or lesser degree, thereby leading to an enormous range of possibilities for the more adventurous palates.
¡Cheers!
