It isn’t true that all geologists drink beer. But many do,
and I’m one of them. Today I’m going to talk about the
intimate connection between geology and beer.
Beer is mostly water, and water chemistry has everything to
do with beer styles. And water chemistry itself depends mostly on the kinds of
rocks through which the water flows. You know about hard and soft water – hard
water has more dissolved chemicals like calcium and magnesium in it, and while
salts of those chemicals can precipitate out of hard water, making a scum on
your dishes, they also can be beneficial to development of bones and teeth. In
the United States, the Midwest and Great Plains have some of the hardest water
because of the abundant limestones there, and in Great Britain, southern and
eastern England have harder water than Scotland for similar reasons.
But it wasn’t limestone that made Burton-upon-Trent a center
of brewing in the 19th Century, when it was home to more than 30
breweries. The water there is rich in sulfate which comes from gypsum, calcium
sulfate, in the sandstone underlying the region. Those sandstones are Permian
and Triassic in age, representing a time when much of the earth was arid. Those
dry conditions allowed gypsum to crystallize in the sediments. Gypsum is much
more soluble than limestone, and the slightly acidic waters of Burton help with
that. Burton water has ten times the calcium, three times the bicarbonate, and
14 times the sulfate of Coors’ “Rocky Mountain Spring water” in Colorado. That certainly
makes Coors’ Burton brewery product rather different from that made in
Colorado.
In fact, the addition of gypsum to beer is called
“Burtonization.” This increases the hops flavor, but more important to history,
sulfates act as preservatives in beer, enough so that Burton brews of pale ales
could survive the long trip to British India, giving us the India Pale Ale
style of beer. Not from India, but brewed with sulfates derived from gypsum in
Britain’s rocks.
That slight acidity in Burton’s water depends on the calcium
and magnesium content, and also lends itself to extracting sugars from malted barley
in the mashing process. Calcium and magnesium also help yeast to work its
magic. Today, home brewers can buy “Burton Water Salts” to imitate the product
from England.
Less hoppy beers often originated in areas where the sulfate
content of the water was low. Pilsen in the Czech Republic, home to pilsner
beer, has almost no sulfate and only 7 parts per million calcium in its water,
compared to around 300 for Burton. Pilsen is in an area of metamorphic rocks
that don’t yield the typical hard-water-making elements.
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| Truman, Hanbury, Buxton & Co., Black Eagle brewery, Derby Street, Burton-upon-Trent, in 1876, from University of London |
The presence of Carboniferous age limestones in Ireland make
waters that are high in calcium and carbonate, but they lack the sulfate of
northern England. Together with other differences, that makes the area around
Dublin ideal for making a stout porter known today as Guinness.
After water, it’s the soil that makes the most difference to
beer. Hops can grow in a wide range of soils, even the decomposed granite we
have here in Butte, but the thick, well-drained soils of Washington and Oregon,
weathered from volcanic rocks, make those states the source of 70% of the hops
grown in the United States.
The surge of craft breweries in the United States has given
rise to some interesting geological names for brews. Great Basin Brewing in
Reno and Sparks, Nevada, has Ichthyosaur IPA, known as Icky, as well as
Orogenesis, a Belgian-style amber ale. Socorro Springs, in New Mexico, brews
Isopod Pale Ale and Obsidian Stout is available from Deschutes in Oregon. You can get Triceratops Double IPA at Ninkasi
Brewing in Eugene, Oregon, and Pangaea Ale at Dogfish Head in Delaware. And
even though it’s more chemical than geological, we shouldn’t leave out Atomic
Ale’s Dysprosium Dunkelweizen, made in Richland, Washington. Dysprosium is a
rare-earth element found in the phosphate mineral xenotime and other stranger
minerals.
San Andreas Brewing Company, near the fault in California, boasts
Oktoberquake and Aftershock Wheat.
And I’m undoubtedly prejudiced, because I’m the House
Geologist at Quarry Brewing here in Butte, which probably has the best mineral
collection in a brewery in the United States, but I think their collection of
geological names for their beers is unexcelled: Shale Pale Ale, Galena Gold,
Open Cab Copper, and Gneiss IPA, and seasonals including Albite, Basalt,
Bauxite, Calcite, Epidote, Halite, Ironstone, Porphyry, Opal Oktoberfest,
Schist Sour, Rhyolite Rye Pale Ale, Pyrite Pilsner, and more. Mia the bartender
and I tried to come up with a fitting name for a 50-50 mix of basalt and
gneiss. I wanted it to be charnockite, but we ended up calling it Mia’s
Mixture.
Next time you enjoy a beer, thank geology!
—Richard I. Gibson
Image: Truman, Hanbury, Buxton & Co., Black Eagle brewery,
Derby Street, Burton-upon-Trent, in 1876 from University of London
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