Valentine’s: I’m Not Bitter, I’m SourThe how and why of sour beers
Melissa Cole doesn't really like Valentine's Day. But she likes to put her bitter feelings aside to talk about sour beers.
Sure, I could make lots of statements about how any display of love is positive and that it’s good for pubs and restaurants and blah, blah, blah but I find it excruciating and I am happy to excoriate it for what it is - a venal money grab with its roots in beating women and murdering saints. And with all this adorable information in mind, this month’s jolly column is about sours and the definition thereof!
What is sour beer?
But what is a sour beer? What makes a beer sour? And are we frequently getting it wrong when we talk about them?
We perceive sour when hydrogen ions are split off by an acid dissolved in a watery solution and the main souring agents in beer are bacteria, which turn up in different forms in different beers.
Lactobacillus (Lacto) and Pediococcus (Pedio) are the two most important bacteria in sour beer production and, pernicious little buggers that they are, will find their way via a number of different ways.
Lacto is the most straightforward one to address, and probably the predominant acidic note in modern beers at the moment as it’s what is used in beer styles like gose and Berliner Weisse - like Magic Rock’s Salty Kiss and Siren Calypso - which particularly when brewed with additional fruit or dry-hopped can be really accessible and refreshing.
Introduced in a few different ways to the brewing process: it can be introduced into the mash, which is then kept warm for a few days by the brewer until it reaches the desired pH of 4.5, or introduced in the kettle, which tends to be a little more reliable and controllable or it can also be added afterwards, although this is less common and, I find personally, a bit more harsh on the palate.