With Octoktoberfest beers flowing this season, it seemed only appropriate to have a post about the marvels of this wonderful, frothy beverage.
A few months ago, I was walking through the Beerology exhibit at the Museum of Man in San Diego, where I saw something so shocking it made me stop dead in my tracks. In a glass case was a two-thousand-year-old bone of an ancient Egyptian that, under UV light, glowed green from excess tetracycline. Tetracycline, an antibiotic that was technically discovered in 1948, was staring right back at me from the bones of an ancient Nubian.
How did ancient Egyptians 2,000 years ago get their hands on modern antibiotics? Investigators propose two ideas. First, the antibiotic came from the ancient Egyptian diet, much like how antibiotics are found in our bodies today, or the tetracycline was a result of microbial contamination. In 1981, Emory University bioarcheologist George and his team were routinely looking at the bones when they discovered something very peculiar. When examining slices of the 2,000-year-old bones under UV light the researchers saw small yellow and green bands indicative of tetracycline mineralizing inside the bones. Tetracycline exhibits an interesting quality; it binds to the calcium in newly formed bone. This process is called “tetracycline labeling” and it is so effective the medical field uses it to measure bone growth over time. Dr. Armelagos’ team thought evidence of tetracycline labeling in 2,000-year-old bones was enough to convince their colleagues that the antibiotic observed came from the diet of ancient Nubians, potentially a specifically brewed beer. However, at the time, this datum was dismissed by the archeological community as simply contamination from tetracycline-producing microbes.
Nearly thirty years later, Dr. Armelagos went back to the ancient bones to prove that the glowing ancient bones were indicative of dietary tetracycline of ancient Egyptians and not from post-mortem contamination. He partnered with Mark Nelson, a medical chemist from Paratek Pharmaceuticals, to help to isolate tetracycline from these ancient bones. The two researchers wanted to prove that the tetracycline was found bound to the bones, characteristic of how ingested modern tetracycline labels bones, and therefore help prove that the antibiotic was consumed before the ancient Nubian passed away.
To extract the antibiotic, the bones were dissolved in hydrogen fluoride, one of deadliest acids on the planet. This was to demineralize the bone and encourage tetracycline free itself from the bone. The dissolved bone was then analyzed using Liquid Chromatography Mass-Spectroscopic (LC/MS). LC/MS is used by scientists to determine the weight of different molecules. Chemicals have specific weights, so if scientists can determine the weight of chemical, they, therefore, can identify what that chemical is. The LC/MS data revealed tetracycline’s molecular weight inside the dissolved bone. Dr. Armelagos and his team argued that because tetracycline was found inside of the bone, the antibiotic came from the ancient diet and not from contamination. Specifically, Dr. Armelagos and his team claim ancient Egyptians consumed their antibiotics with a specialty brewed beer.
So where did this beer come from? First, let us take a step back understand the composition of modern beer. Modern-day brewers create all of the known varieties of beer from IPAs to Pale Ales by combining only four ingredients: water, barley, hops, and yeast. Hops, cone-shaped flowers from plants in the hemp family, act as beer’s bittering and flavoring agent, as well as its preservative because hops release natural antimicrobial compounds to suppress unwanted microbial growth. Most of the yeast used in the modern beer production are commercialized strains of Saccharomyces cerevisiae. Fun fact, the Miller Brewing Company has used the same strain of lager yeast over 160 years! However, over the past few decades, the beer industry renewed its focus on finding different yeasts and yeast strains to produce distinctive types of beer styles. Several yeast manufacturers create yeast banks from which anyone, homebrewers to large beer companies, can pick out the perfect strains of yeast for producing specific types of beer. In academia, different labs cross-bred various yeasts to engineer the perfect microbes for different beer styles.
Thanks to pasteurization, nearly all modern brewers use only four ingredients to make beer (again, water, barley, hops, and yeast). Ancient brewers, on the other hand, were more creative in producing their desired beverage. They created alcoholic drinks from everything imaginable: corn, cactus, rice, millet, barley, honey, grapes, dates, and roots. To flavor their alcoholic beverages, ancient brewers used a plethora of various spices, berries, flowers, and even hallucinogens such as Cannabis and poppies! They also included oddities such as mudwort, pine needles, and woodworm to their concoctions. Additionally, to ferment their mixture into alcoholic drinks, ancient brewers unwittingly used a rainbow of natural yeast and bacteria to introduced their own flavors and metabolites. This dazzling array of beer varieties is vastly more complex than our simple four-ingredient beers today.
Which brings us back to our original story of the antibiotic beer from ancient Egypt. How could have it been made? Ancient peoples were masters in their own right at producing different types of beer, and it is well documented that certain beverages were for medicinal purposes. It is hypothesized that Streptomyces, the soil-dwelling bacteria that produces tetracycline, was inadvertently mixed into the fermentation process of ancient Egyptian beer. As the barley plants were pulled up from the ground and thrown into the fermentation vessel, their soil-dwelling microbes piggybacked with them. The Streptomyces colonies looked like golden lumps floating on top of the fermenting beer. This beer with the floating, golden lumps made ancient people with common bacterial infections such as small infected wounds and urinary tract infections feel better, so brewmasters perfected their specialty beer. Dr. Armelagos and his team of researchers hypothesize this beer was made by inoculating a new batch of beer with some of the Streptomyces contaminated beer from the previous batch. This way the brewmasters from thousands of years ago could create a beverage with a high enough concentration of the antibiotic for it to be an effective ancient medicine.
To prove the beer can be produced in the first place, grad students in Dr. Armelagos’ lab recreated the beer in question. Recreating the 2,000-year-old antibiotic beer was a success, but there was little praise about the taste of the sour, liquidly porridge beer. I guess it was an acquired taste.
At the time beer was not the clear, bubbly beverage we are familiar with today. It was more like a thin gruel. People would drink the beer first, then eat leftover porridge. It was beer two ways! If you use a bit of imagination, you can compare it to fresh orange juice where you drink the juice then eat the pulp later.
To me, this story begs the question: what other secrets are lurking in the recipes of ancient beer? Other antibiotics? Other flavor profiles? Some craft breweries with such as Avery Brewing Company in Boulder, Colorado and Dogfish Head Brewery in Delaware may give us some insight into this question. With founders of these breweries dedicated to recreating ancient beer, we may once again be able to discover something that makes us stop dead in our tracks.
So, let’s go for a drink!
