Episode 387 Geology of Beer

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 19^th 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.

Truman, Hanbury, Buxton & Co., Black Eagle brewery, Derby Street, Burton-upon-Trent, in 1876,
from University of London

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.

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

More Geology of Beer 
And another from Lisa Rossbacher

Image: Truman, Hanbury, Buxton & Co., Black Eagle brewery, Derby Street, Burton-upon-Trent, in 1876 from University of London