In 2015, workers were reconstructing the old Raven Trading brewery in the Czech Republic, when they stumbled upon three bottles of beer that date back to the early 20th century.
The untouched bottles offered an opportunity for researchers to not only see how beer was brewed around the time of World War I, but also study the chemical changes that happen in beer over long periods of time.
The beer was bottled in dark glass, well-sealed, and stored in a large cold cellar at the brewery. The beers ranged from intensely sulfuric to sour, and had flavors that ranged from fruity to fecal.
Using liquid chromatography and other techniques, the researchers compared the beers to modern day brews. The beer from back in the day had higher alcohol content and was less bitter. They also contained more iron, copper, manganese and zinc.
The researchers found that the chemical changes to two of the beers were likely caused by microbial contaminants, but the third beer, which was better preserved, offered the best insights into the aging process.
The third beer was light brown, slightly bitter, and still had traces of carbon dioxide bubbles. The researchers offer an in-depth analysis in a report in the Journal of Agricultural and Food Chemistry.
This is IEN Now with David Mantey.