Peter Dolan explores the interaction between these two essential ingredients for a fulfilled life.
Prof. Bryan Lovell President of our Society (2010–2012) wanted two non-core subjects addressed during his tenure. First was to encourage an interest in links between geology and poetry. This was achieved when on 10 October 2011 a meeting was held at the Society largely organised by Michael McKimm (now our User Services Librarian) who himself produced a thought-provoking book of verse entitled Fossil Sunshine. Secondly, Prof. Lovell was keen to encourage enquiry into links between geology and beer, eschewing the poetic licence sometimes associated with the latter. Perhaps something to match the entertaining and informative publications and discourses linking geology and wine, so ably researched by Prof. Richard Selley.
The author was asked, by virtue of connections with the real ale industry, to take on this task. For reasons too myriad to recount he failed dismally but, in an attempt to redress the matter, has compiled the following with input from various drinking friends and more reliable sources. Of these, by far the most useful reference has been ‘A History of Beer and Brewing’ by Ian Hornsey which was published by the Royal Society of Chemistry (RSC) in 2003. The juxtaposition of the RSC with the Geological Society in the Quadrangle of Burlington House is a coincidence that sits comfortably with contemplating the links between geology and erudite aspects of brewing.
Another treasure-trove of information on ancient beers, as yet unassimilated by this author, is the website of Patrick E. McGovern, Scientific Director of the Biomolecular Archaeology Project for Cuisine, Fermented Beverages and Health at the University of Pennsylvania. The hope is that those with less jaded taste buds and more current internet search skills will take up the challenge to better explore the subject and, ultimately, produce a map of UK geology overlain with beer types (pubs would be a useful second order data set). So, with a beer-induced lack of scientific rigour, let’s start at the beginning:
Follow the Grasses
The Alpine-Himalayan mountain chain has of course been developing for tens of millions of years and has been the source of many large south flowing river systems. At some point in the recent geological past two major rivers developed, the Tigris and the Euphrates, with their combined drainage basins becoming known as Mesopotamia.
As the climate of 15,000 years ago ameliorated after the last ‘ice age’, Mesopotamia and surrounding areas became fertile and the wild grasses which flourished eventually provided the catalyst for early nomadic humans to settle, at least in part, into a more sedentary life-style, taking advantage of crop cycles and laying down the foundations of civilisation. (Similar agrarian forces were at work in Eurasia, Eastern Asia and Central America, but not Africa, Australasia, North America and South America.) It is perhaps a telling commentary on mankind that some of the first communal activities at the dawn of civilisation were bread-making and brewing – plus ca change...! Received wisdom is that brewing commenced about 8,000 years ago; a result of the chain of events from mountain building, palaeo-drainage systems, fertile soils, benign palaeo-climates and flourishing grasses.
With the feedstock and knowledge to brew ancient beers, there was, of course, the need to contain them. Some amongst those early civilizations must have become the first geologists, being able to identify suitable clays which could be fired into crude pots and dishes, and ‘hard’ rocks for grinding quernstones.
It didn’t take long for beer production to become well established outside Mesopotamia. There is evidence of beer production in Egypt about 6,000 to 7,000 years ago, an activity which reached massive proportions, enough for expanding populations and even for export. The early soil scientists had learned more by this time, enough to select suitable clays for kilns and constructing brewery buildings as well as finer containers for storage and transport. Ian Hornsey mentions Pelusium (a city at the easternmost mouth of the Nile), apparently as important in Egyptian brewing history during Roman times as Burton-on-Trent has been in England. In fact, tongue-in-cheek, there’s another connection between Burton-on-Trent and Pelisium, namely IPA; Indian Pale Ale (exported to India) and Imperial Pelusian Ale (exported to Rome).
The Geoscientist being the magazine of the UK-based Geological Society, what of the British Isles specifically? When Julius Caesar arrived in Britain in 55BC he found that beer was already being brewed here. Brewing knowledge had either spread from those early geologists of Mesopotamia and Ancient Egypt or there was a clear case of parallel behavioural evolution. Whichever it was, cereal crops were well established throughout Neolithic Britain by 5500 years ago, requiring our first compatriot geologists to identify raw materials for tools and the most basic manufacturing.
Probably one of the most successful early centres of cereal cultivation was across Salisbury Plain. Whether or not brewing took place here is apparently not known, but it wouldn’t be surprising if whatever rites were associated with Stonehenge, they incorporated consumption of some potent brews of the time in addition to the daily needs of very extensive (according to recently published news) communities in the area. Then there are those allochthonous ‘blue stones’ from Preseli in South Wales, identified by an early igneous petrologist, surely he and the workers moving them could have benefited from a little tipple now and then.
Implied in the foregoing is that to identify where beer may have been consumed one has to ‘follow the grasses’. Within Britain, the palaeo-climate ameliorated sufficiently during Neolithic times for the ‘improving’ climate to allow cereals to flourish in Scotland, at least as far north as the Orkneys. Brewing of beer flourished into the Beaker Culture and Bronze Age (about 3000 and 1000 BC) and our early geologists were called upon to identify and exploit finer clays as well as flints for axe heads and knives, copper and tin for bronze tools and ornaments. According to Hornsey, the highly successful Beaker Culture may well have been based on a widespread ‘drinking cult’ that fuelled competition. This would presumably have been manifested in feuds, attempts to dominate agriculture and efforts to find and protect valuable raw materials. Our earliest mining geologists were perhaps prey to drunken hoards.
About 500 BC new generations of British mining geologists were spawned when the Celts arrived from the Low Countries and France, bringing with them knowledge of working a new metal; iron - much harder than bronze. The first iron workings in Britain were probably in the Weald and Forest of Dean. As Hornsey, again, remarks, the Celts were also competent carpenters and are credited with inventing the iron-hooped stave barrel. So, the mining geologist found the iron to hoop the barrels. When these had served their purpose the ancient hydrogeologist came to the fore, sometimes using the barrels to line water wells. Beyond this, the importance of iron agricultural implements can hardly be overstated in the context of establishing fixed agricultural sites and their associated communities. So, we have a series; mining geologists, iron-ore, communities and beer drinking cults; (no comparisons should, of course, be drawn with the modern-day Pilbara!).
As iron implements enabled the tilling of progressively heavier soils and the spread of ‘fixed’ communities, Britains agricultural wealth increased, particularly with good quality grains; some think this was a significant motivation for the Roman invasion. Barley was of sufficient importance to Roman society to be depicted on some Roman coinage, (cue our mining geologists again). In the same vein, in 301 AD, the emperor Diocletian fixed the prices of key commodities, including British beer (shades of the EU). The distribution of that beer, deemed to be an essential commodity, was greatly enabled by the construction of permanent roads; hence a need for engineering geologists to help slake the thirst of centurions and plebeians.
Moving on, Medieval history in Britain and continental Europe has legions of references to beer production, quality, price and consumption. In England, Canterbury, Ely and Winchester, all religious towns, were early centres of brewing excellence, perhaps founded on rich agriculture which itself was based on local geology yielding fertile soils. Similarly, the Benedictine Abbey in Derby, founded in 1004, became famous for its excellent ales, in this case perhaps as a result of favourable groundwater.
Hops
The earliest date when hops were used in brewing in Britain is uncertain; they may have been used as a ‘taster’ before the Norman Conquest. However, by the end of the 14th Century there was trade in hops and hopped beer, particularly with the Low Countries which led to domestic cultivation of hops, probably initially in Norfolk and Kent. Solid geology influences soil structure and pH which are important for some hop varieties though many are tolerant to a wide variety of soil types. Having said this, it may well be that Norfolk and Kent became prominent areas of hop cultivation primarily due to them having thriving ports which traded with mainland Europe rather than any inherent geological attributes.
Fuel
Whilst brewing had become ubiquitous in the UK by the 14th Century, it may have been that some of the more successful areas had ample supplies of wood or coal in close proximity. These fuels, in contrast to peat, enable a steady heat to be produced, as is required for kilning and boiling.
At the end of the 16th Century much of southern England was deforested and coal was shipped in from Northern England. So, early coal prospectors were playing their part in keeping the many London breweries operating and the brewing industry became one of the major coal-consumers prior to the Industrial Revolution. The sulphurous gases emanating from this intensive burning of coal (cf modern China) in London led to the rapid realisation that the smokeless anthracites of South Wales had far superior thermal qualities. The most successful of experiments to rid coal of some of its noxious gases, possibly by some technique similar to the production of charcoal, were in Derbyshire. Renowned Derbyshire ales were brewed with malt kilned over these ‘coaks’, themselves obtained only from a particular coal mined near Derby – so emerged some geological knowledge of coal that was particularly relevant to brewing.
Over the next 300 years brewing became a fundamental part of British society and geologists continued to play their part in the supply chain. For others it was a different relationship. In the case of William Arkell, it was the sale of beer which provided the wherewithal to make him of independent means and able to pursue an academic and consulting career dedicated to understanding the stratigraphy of Jurassic strata. The Arkell Brewery, started in 1843 by William’s forebearers is still in production.
The latter half of the 20th Century witnessed an inexorable decline in the number of breweries in the UK as brewing became concentrated within just six companies concerned with efficiencies, land values and ‘the bottom line’. For the geologists (and everybody else) with a discerning palate for beers, matters appeared dire. Then in 1971, the Campaign for Real Ale (CAMRA) was conceived and with general public support CAMRA lobbied to save breweries and public houses from closure and encouraged the establishment of new breweries, to become affectionately known as ‘micro-breweries. The first such micro-brewery was established at an old brewery site in November 1972 in Selby, well known to geologists as the site of one of the UKs largest coal mining operations; was there a connection? The first totally new UK micro-brewery was established in 1973 in Priddy, Somerset. Oh that it had been 10 years earlier when the author was a geology undergraduate who caved in the Mendips.
Geochemistry
Brewing water has been mainly drawn from groundwater wells or springs and so the geology of the aquifer directly influences the concentration of key ions from the minerals and the pH. However, the salt content of the water (liquor) makes only a small contribution to the total mineral content of the beer; moreover the influence on the palate is only an indirect one because different salt ions affect different enzymic and other reactions which take place at mashing in different ways.
So, whilst the chemical nature of liquor used in the brewing process exerts some influence over the key flavour characteristics of beer (taste and aroma), other factors are much more influential. These factors include the flavour and colour characteristics of the various malted barleys in the grist recipe (including roasted barley in stouts), the hop varieties used for both wort boiling and for dry hopping and the degree to which they are used for both processes, and the different yeast strains and fermentation profiles.
As well as the chemistry of groundwaters, geology also influences the growing of malting barley in the British Isles, since it thrives particularly on poor quality chalky soils. In contrast, in the USA, the majority of malting barley and hops are grown on alluvial fans of volcanic soil.
Before ‘mains water’ various styles of beer arose as a result of brewing with convenient local supplies of water, each with its own subtle chemistry. Thus Burton-on-Trent has water high in calcium sulphate (gypsum), which makes the beer stable and brings out its bitterness of beer, so giving them their distinctive taste (also for a propensity to induce flatulence). London and Dublin waters are higher in chloride and lower in sulphate concentrations, which gives a softer taste, and so porter and stouts became strong beer types. In contrast the soft water of Pilzen in the Czech Republic is ion depleted and this results in a light dry lager/pilsener type.
More specifically key cations are calcium, magnesium, sodium potassium and iron. Calcium stabilises yeast enzymes and precipitates phosphate correcting the acidity of the water; magnesium has a similar effect but in excess gives an astringent bitter taste; whilst sodium/potassium in excess give disagreeable harsh flavours and can have a laxative effect. High iron content leads to rapid degeneration of yeast with consequent tailing off of fermentation power and also a tendency to throw a colloidal haze; barley steeped in water with a high iron content results in malt with a grey appearance and poorer brewing quality.
Key anions are carbonate, sulphate and chloride. Carbonate buffers against a fall in pH which has an adverse effect on mash enzymes leading to a reduced brewhouse yield; sulphate supports the release of bitter components from the hops and reacts with magnesium to form magnesium sulphate, a bitter tasting salt; whilst chloride in high concentration can give a salty/bitter flavour but when in lower concentrations, palate fullness and sweetness predominate.
Aquifers
The chemical components of ground-waters and their effects on beer, described above, determine some of the classic beer types derived from aquifers in classic areas of European beer production, such as:
- Burton–on-Trent: well water comes from evaporate rich Permo-Triassic sandstones and is hard and high in calcium and sulphate. (Bitter, including India Pale Ale [IPA]).
- Dublin: has water derived from Carboniferous Limestones. (Porter and Stout including Guinness).
- London: waters are from Cretaceous Chalk which gives a slightly different ion composition to the Dublin waters. (Porter and Stout).
- Munich: draws water from Recent sediments and is closer in character to Dublin water (Dunkel).
- Dortmund: derives water from Coal Measures sandstones, and is similar to that at Burton, but less strongly mineralised (Pils).
- Scandinavia: has water which is usually poorly mineralized being derived mainly from fractured Precambian rocks (Pale Lager).
- Denmark (Jutland): has essentially Cretaceous geology overlain by Tertiary deposits giving water rich in calcium carbonate and similar to those of Munich. (Jutland Porter).
- Bohemia, Flanders and other areas of similar geology: have groundwaters with low ion levels, especially of calcium and sulphate, that are derived from sandstones or impermeable Lower Palaeozoic and Precambrian metamorphic rocks. Thus the low content of dissolved minerals and ions gives a light dry beer with a less distinct flavour (Pilsener).
Post World War II, and since the advent of the brewing chemist, de-ionization and/or liquor treatment has become a common process at all breweries in order to match the desired mineral composition, irrespective of the natural geology of local aquifers.
Brewing Filters
Part of the process to produce a beer of sufficient standard for consumption today is to remove yeast and other extraneous material by filtering. Two common filters are kieselguhr, comprised of siliceous diatom shells, and perlite, a volcanic siliceous glass of aluminium silicate. A roll of the drums here for sedimentologists and volcanologists.
Beer Containers
- Pottery: As we have seen earlier, at the outset of brewing, clay pots of some description were needed to contain ales. Such basic containers were probably used until at least Roman times and then in more recent times stoneware bottles were developed. Both, of course, used materials derived using some geological knowledge.
- Skins: although not linked to geology, it should be mentioned that containers of animal hides or viscera were probably used in ancient times.
- Wood: Hollowed-out wooden containers can well be imagined as having been used in the past. But the use of wood became important when metal hoops were adopted to secure stave barrels. The identification and exploitation of iron ore was key to this.
- Glass: In the UK, it was in the late 16th Century that experiments to store beer in bottles were first attempted by domestic brewers. The first commercial attempts to bottle beer were a century later, which must have been the catalyst to finding large quantities of suitable silica.
- Metal: Canned beer was first produced in the USA in 1935 and then immediately afterwards in Llanelli, Dyfed – not a mere coincidence but because the Felinfoel Brewery founder was also the owner of local tinplate works. Since then aluminium beer cans and steel kegs have been developed – all require the efforts of mining geologists.
- Plastic: Finally, there are numerous types of plastic bottles, all derived ultimately from petroleum, petroleum geologists take a bow.
Conclusion
Geology is a fundamental control on many elements of civilisation so it is no wonder that it is inextricably linked to one of the oldest concoctions of Mankind. More specifically, many a geologist has been involved in beer-fuelled debates about knotty field-mapping problems. It is not a huge leap from this observation to say (as attributed to John Wakabayashi of California State University) that “The strongest connection between geology and beer is the love that geologists have of beer”.