So what exactly is ‘Belgian beer’?

You may be familiar with the old adage “you don’t really know something until you can teach it to someone else.” This rang true recently when I set out to answer the question above. Solvay Society is taking part in Ales Tales, a Belgian beer festival next month at Oval Space, London, and the organisers had asked me for my thoughts.

So what do we mean by ‘Belgian beer’? Is it provenance? Well, surely not because then most of our Stella Artois would be ‘Belgian beer’. What about ‘terroir’? This may capture what is Belgian about ‘Lambic’ beers, which are spontaneously fermented using yeast and bacteria naturally present in the air of the Senne Valley and Pajottenland, south-west of Brussels. But we know that Belgian beer encompasses more than this famously challenging type of sour beer. Moreover, many beers we identify as ‘Belgian’ most probably contain ingredients grown outside the country. So what about taste — is there a ‘Belgian flavour’? This is key, and the best starting point.

The Beer Judging Certification Programme is the source of criteria for many beer-judging panels. As such, their style guidelines are a good start to understanding different styles. Quickly scanning the sections dedicated to Belgian beer, one finds the same words coming up repeatedly: fruity, spicy, balance.

The fruity and spicy notes that we have come to identify as ‘Belgian’ are the result of by-products generated by yeast during fermentation. Many Belgian beers — such as the tripel, wit and saison — have characteristic clove and white pepper aromas. These are simply the way we perceive the presence of moderate concentrations of a compound called 4-vinyl guaiacol, or 4VG. 4VG is produced when an acid present in the husk of malted barley is broken down by an enzyme produced by certain yeast strains. Many Belgian ale yeasts produce this enzyme.

Fruitiness in beer can be derived from hops, but it is also the result of esters. Esters are normally associated with yeast stress, such as warm fermentation temperatures, lots of simple sugars present in the wort and insufficient oxygen available during yeast growth. This can lead to aromas of pear (ethyl decadienoate), so characteristic of Duvel’s famous strong golden ale, as well as banana (isoamyl acetate) and bubble-gum (ethyl butyrate), a key component in Solvay Society’s Tritium. These compounds are produced in higher concentrations by many yeast strains in classic Belgian beers.

It’s quite clear therefore that we associate certain flavours and aromas with Belgian beers, many of which have been derived from the choice of yeast and fermentation profile. But what about ‘balance’? There’s no general theory on this. To some people it means “IBU to OG ratio” (a ratio that compares the amount of bittering compounds to the sugar concentration in the wort). But this doesn’t tell the whole story.

For Solvay Society, balance is driven by the concept of the beer. It should be cohesive. It should coat the tongue and not linger. It should be aromatic and pleasant, seamlessly combining hop and yeast aromas. Bitterness and alcohol should be firm and noticeable but not harsh. These essential attributes make a beer ‘balanced’ — and make it quintessentially, classically Belgian.

Ales Tales will be held in East London on 22–23 July and will be the most comprehensive modern Belgian beer festival hosted in the capital.

The list of breweries currently includes: Solvay Society; Brasserie de la Senne; Monsieur Rock (Orval’s former head brewer’s solo project); Hof ten Dormaal (a genuine Belgian farmhouse brewery); Glazen Toren (purveyors of some really unique beers); and many more TBA