The Geology of Beer

The Geology of Beer

The pleasures of beer consumption are encapsulated in the following quotation, from an unknown source.
The enjoyment of a glass of beer may be received by many senses: the sight may be attracted first by the clarity of a pale ale or the rich creamy head of a stout. As the glass is raised to the lips the aroma of the beverage, possibly the bouquet of the essential oils of the hops, may excite the nostrils. Then, as the liquid flows over the taste buds at the back of the mouth, and further volatile products diffuse into the back of the nose, the flavour of the beverage is perceived. Finally, the beer enters the body, where the alcohol is rapidly absorbed into the bloodstream and exerts its well-known physiological and psychological effects.
In more formal terms, in any particular brew the brewer is seeking a combination of five characteristics: flavour (including both taste and aroma), alcohol content, colour, head retention, and clarity. The chemical nature of the water used in the brewing process exerts a strong control over all of these.
In Ireland at about the same time attempts to brew bitter beers had failed, though it was found that the waters used in brewing there were ideal for beers of the porter type. The reason is that most of the waters used in Dublin and Cork in particular are derived from the Carboniferous limestones in the centre of the country and are thus dominated by carbonate. The most famous of these brews was developed by Arthur Guinness in Dublin, who produced his extra stout (meaning thick) porter, which on contraction introduced the word ‘stout’ into the language of brewing.

guinness-beer-for-halloween
Many countries in the European Beer Belt use mineralized groundwater for their characteristic brewing, and this is highlighted by the following examples. Two of the classic brewing areas of Germany are Dortmund and Munich, where mineralized groundwater determines the brew type. In Dortmund much of the water is derived from the Coal Measures, where waters similar to those in Burton-on-Trent are found, though they are not as strongly mineralized and have a higher carbonate content. The classic ‘Dortmunder’ is bottom-fermenting, as one would expect in Europe, has enough sulphate to be well hopped, and has a high enough total mineral content to promote good fermentation and thus produce a clean, dry beer.

GERMANY-POLITICS-MERKEL
Munich on the other hand draws water from more recent rocks, which, is closer to the water of Dublin in chemical composition. The classic Munich beer is sweet, full, dark, and brown, to all intents and purposes the equivalent of stouts and porters. Denmark, particularly in Jutland, has an essentially Cretaceous geology overlain by Tertiary deposits. The naturally occurring groundwater is similarly rich in calcium carbonate and the response to this is the brewing of sweet, dark beers termed Stowts.
However, in much of Europe the groundwaters, whether derived from surface run-off, sandstones, or impermeable lower Palaeozoic or Precambrian strata, have very low levels of both calcium and sulphate. In these areas the beers that are produced are alcoholically strong but lightly hopped and texturally thin.
This type of beer was developed initially in the town of Pilsen in Bohemia (now in the Czech Republic). A critical process was the storage of the fermented beer in cold caves – lagering – and thus two new terms were introduced into the brewing vocabulary, pils and lager. This direct response to brewing with waters of low ion content spread rapidly in the 1880s throughout those areas of northern Europe where such waters are common.

bohemia
This included the Netherlands, Germany, and Denmark, where to this day lager is recognized as a major beverage.
So far, no mention has been made of another important brewing nation, and that is Belgium. The country is fascinating, as geologically it is not always very promising as far as brewing waters are concerned, but it illustrates a classic example of a unique response. Simply, in areas where there are useful mineralized waters, use them to their best effect; otherwise, ignore the rules. In East Flanders, particularly around Oudenaard, there are carbonaterich waters, and the characteristic Brown Beers are top-fermenting, dense, and smooth. These contrast markedly with the Red Beers of West Flanders, where the less mineralized waters lead to the brewing of light and not very bitter beers. There are four monastic Trappist breweries in the Ardennes, where the waters are highly enriched in calcium carbonate and as a result the typical brews are top-fermenting, dark brown, and sweet. There is a fifth brewery at Westmalle, north of Antwerp, where the water is hard and a brew much closer to a bitter ale is produced. Where the waters are poorly mineralized there are only two options. First, there is the classical approach into pils brewing, typically around Louven, Alken, and Lindberg where the groundwater is derived mainly from superficials and surface run-off. Second, there is a much more idiosyncratic Belgian approach, which is the production of Lambic, traditional in the Brussels area. In this style wheat and malted-barley beers are produced using naturally occurring wild yeasts, which ferment completely and are very dry. Hops are used not for flavour but purely to protect the beers from unwanted infection. Fruit flavourings are often introduced, the best known being black cherry (Kriek) and strawberry (Framboise).
Scandinavian brewing is dominated by lager-style beers, as would be expected from poorly mineralized waters derived mainly from Precambrian rocks, though occasionally a Belgian style approach is attempted, as with the juniper-flavoured beers of Finland.

And so finally know your beer….

learn-the-different-types-of-glasses_530cfac7029c3

(Excerpt from The Encyclopedia of Geology-Volume five)

Related post Geology of Wine

Post author

The RocKe Scientist is an award winning earth science platform based in Kenya.

There are 1 Comment

  1. Posted by Tracey Reply

    Love it!!! Love it!! Love it!!!

Leave a Reply