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Brewing with Recycled Wastewater: Beer History Made in Arizona

I’d never heard the phrase “toilet to tap” before judging in the “Arizona Pure Water Brew Challenge” brewing competition.

Arizona Pure Water Brew Challenge

Let me back up.  (Ah, toilet humor.)

As a certified beer judge, my name and email address are distributed to folks who organize brewing competitions.  As of this writing, there are about 6,599 active BJCP-certified beer judges in the world, with 5,218 residing in the U.S. To put those numbers into prospective, our population size is about on par with that of the critically endangered Black Rhino.

So the call went out to beer judges at the end of July for the AZ Pure Water Brew Challenge set to take place on Saturday, September 9th in Tucson, AZ.  I’ll be honest with you, I answered “yes” before I understood anything about what the competition was about.

Well, I take that back. I knew it was a brewing competition among professional breweries across the Grand Canyon State, and it seemed to have something to do with “Pure Water”.

And water, as any brewer worth his salt will tell you, is a key component in beer not just because it makes up the majority of the beverage ingredient-wise, but because the particular water composition (minerals, chemicals, pH, etc.) helps to determine the character of the beer, with even minor adjustments becoming noticeable in the final product.

Naturally, some breweries are keen to tout the purity and source of their water such as Coors beer brewed with “100% Rocky Mountain water”, or the Einstök brewery of Iceland that claims to use the “purest water on Earth”, water that flows from rain and prehistoric glaciers down the Hlíðarfjall Mountain and through ancient lava fields.  Gotta admit, that sounds pretty majestic.  [Science seems to think that the purest water on Earth is found in the southernmost Chilean village of Puerto Williams, but who’s counting.]

For clarification, the “Pure Water” used in this brewing competition wasn’t exactly the kind of pure water Coors or Einstök is talking about.

No, the kind of water we’re talking about here happens to be wastewater, treated wastewater— hence the somewhat pejorative phrase “toilet to tap”.

I neglected to realize this minor detail until about a week before the competition, and if I’m being completely honest, I was a bit apprehensive about the whole thing, increasingly so as the big day drew closer.

But, I told myself, people have consumed beer brewed with less than enchanting sounding water before and lived to tell the tale.

Duck Pond Beer

Back in 2011, the documentary How Beer Saved the World featured a segment in which Dr. Charlie Bamforth, professor of brewing science at the University of California, Davis, theorized that beer was responsible for saving millions of lives in Medieval Europe.

The reasoning goes that much of the water in the Middle Ages was rife with deadly pathogens and drinking it was potentially life-threatening to humans.  However, Dr. Bamforth speculated that the fundamental brewing process (which included boiling the brew) prevented dangerous microorganisms and bacteria from making people sick.

To test this hypothesis, Bamforth and his colleagues first collected water from a duck pond.  This water was then lab-tested and confirmed to be teeming with fecal coliform bacteria such as E. coli, which likely originated from duck doo-doo.  That same water was then used to brew beer and after being lab-tested, the beer was designated safe to drink.

Finally, the duck poop beer was served to a group of seemingly unsuspecting publicans in a bar.  The test subjects initially appeared to enjoy the mystery beer, noting descriptors like “perfume-y, nutmeg and salty”.  Of course, this positive first impression only stood to compound the drinkers’ sense of shock upon learning of the beer’s fowl origins.

“Pure Water”

Unlike the duck pond water in the experiment above, the so-named “Pure Water” produced by the Pima County Southwest Water Campus team goes through a much more rigorous purification and strict testing process than simply boiling water.  The process includes ultrafiltration, reverse osmosis, UV/advanced oxidation, granular activated carbon, and chlorine disinfection which remove bacteria, pharmaceuticals, personal care products, heavy metals, viruses, pathogens, etc.

Pure Water: Water Purification Process

In other words, the divisive term “toilet to tap” doesn’t really come close to accurately describing the level of purification and testing “Pure Water” undergoes, although I would have never heard of the term if it wasn’t listed on the FAQ section of the brewing competition website. But better to face these potential objections head on in a campaign to garner public buy-in.

“Our biggest challenge will not be technological; our biggest challenge will be public perception and dealing with the obvious ‘yuck’ factor,” notes Jeff Prevatt, Pima County Wastewater Reclamation Department Research and Innovation Manager.

And what better way to get the general public on board than with beer.  Heck, it seems that the public will stomach just about anything in the name of beer.  Consider commercially produced brewskis that included such eclectic ingredients as bull testicles, beard yeast, vaginal bacteria, cat feces,  and yes even as late as the beginning of 2017, Stone Brewing Co. produced “Full Circle Pale Ale”, a beer brewed with reclaimed water.

Brewing with recycled water can get you a nice media buzz, but in Arizona’s case, the state is slowly sobering to the reality that mandatory water cutbacks may be coming if water levels continue to decline to critically low levels in drought-stricken Lake Mead, a significant source of water for Arizona, California and Nevada.  Add to that Arizona’s relatively low-priory water rights in this case, and let’s just say it’s nice to have an option on deck with “Pure Water”.  [Fun fact: Parts of Australia, Singapore, New Mexico, Virginia, Texas, Georgia, Orange County, San Diego, and many other California cities have already implemented water recycling projects in recent years.  Namibia has been doing it for nearly 50 years.]

To be sure, the AZ Pure Water Brew Challenge was historical in that it was the first time a statewide competition was held that utilized treated sewage water in the beer, especially at a time when water usage concerns are on the rise.  And unlike Stone’s reclaimed water beer that was brewed specifically for the PureWaterSD private one-time event and available only to politicians and VIPs, many of the AZ Pure Water Brew Challenge beers were made available to the general public and have already begun showing up on the beer check-in app Untappd.

But while the brewing competition drew eyeballs, one of the most astonishing parts of this story is that the whole water purification process takes place inside a mobile lab that was converted from a shipping container that opens up like Optimus Prime.

And it was this novel concept of arranging a statewide brewing competition using recycled water produced in a mobile shipping container that won the Southwest Pima Country Water Campus the $250,000 Water Innovation grand prize, which helped make an idea reality.

I know what you’re thinking: all of this is cool and everything, but what was the beer like.

The Judge’s Table

As a competition brewer and certified beer judge, I’ve been on both sides of the judging table.  I know that anxious feeling of waiting to hear the competition results of a beer I’ve put heaps of effort and thoughtfulness into.  And secretly, I think every brewer wants to know what conversations were had about their beer at the judge’s table, especially if they made it to the Best-of-Show (BOS) final round.

Pull up a chair.

Daniel J. Leonard Judging Beer in AZ Pure Water Brew Challenge

Before the BOS, judges paired off and were assigned a few beers to judge, with each set of judges selecting only the best of the round to move forward to BOS.  As fate would have it, I judged round one with my BJCP Certified beer judge sister who had just arrived in Tucson after narrowly evacuating her home in the Caribbean ahead of the approaching catastrophic Category 5 Hurricane Irma.  The beer gods work in mysterious ways, I suppose.

Of the 26 Arizona breweries competing in the competition, seven anonymous entries made it into the Best-of-Show end-game.

Sorting Beers in Beer Competition

So just how were the finalists in the AZ Pure Water Brew Challenge?  The truth is, they were excellent and included a welcome variety of beer styles such as Czech Pilsner, DIPA, IPA, American Pale Ale, Kölsch, Scottish Export and a sour brown ale.  In these kinds of competitions, the winners aren’t determined by whichever beer style the judge has a personal preference for at home, but rather which beer most accurately represents the beer style it claims to be according to the BJCP Beer Style Guidelines.

It was quickly apparent that the winning beer, a Czech-style Pilsner, was stylistically on target— dangerously so— a feat that is typically more difficult to accomplish with such technical lighter beers.  Not to mention, the Pilsner wasn’t over-hopped, which is perhaps the single most common mistake American brewers make with lighter beers, if not most other beer styles.  When Dragoon Brewing Co. was announced to be the brewery behind the winning Pilsner, I immediately thought back to the Cicerone and BJCP Beer Judge certificates that hung in the office of Dragoon’s head brewer Eric Greene.

The Double IPA brewed by one of Phoenix’s most beloved breweries, Arizona Wilderness Brewing Co., was a close second.  From a strategic point of view, entering a big hoppy DIPA into a brewing competition is a smart move because the style is largely a crowd-pleaser.

And Wilderness would have likely won the competition if Dragoon hadn’t taken the bold, perhaps unnecessary, risk of going all in on such an unforgiving style as Czech Pilsner and gotten closer to the stylistic bull’s-eye.

But sometimes, fortune favors the bold.  Fortune, and treated wastewater.

Be Part of Beer History

For a limited time, you can take part in brewing history and sample some of the incredible beers around Arizona brewed from some of the following participating breweries:

Related Articles:

Top 20 Tips for How to Win a Brewing Competition

How to Pass the Online BJCP Entrance Exam

Hi, I’m Dan: Co-Founder and Beer Editor for, Beer and Drinking Writer, BJCP Beer Judge, Gold Medal-Winning Homebrewer, Beer Reviewer, AHA Member, Beer Traveler, and Shameless Beer Promoter.

How Beer Saved the World: The Mystery of Antibiotic Beer Revisited

Back in 2011, the Discovery Channel aired the beer documentary How Beer Saved the World (transcript here), a film that took a look at the origins of beer and also built a case for (spoiler alert) how beer saved the world.

The film fired off one fascinating beer fact after another like how beer was responsible for the start of the agricultural revolution in 9,000 B.C., or how beer built the pyramids of ancient Egypt, saved millions of lives in the Middle Ages, and how beer was to thank for inventions like the wheel, writing, math, and modern medicine, just to name a few.

No doubt, the documentary boasted many a bold claim, but as a beer brewer, I was interested in one claim in particular: a significant amount of tetracycline, a broad-spectrum antibiotic, was discovered in 3,000 year-old Egyptian bones, and the source of that tetracycline was from an ancient beer recipe.

The idea that a modern-day wonder drug like tetracycline was found in 3,000 year-old bones might seem unusual especially considering that tetracycline wasn’t officially discovered and produced by science until 1945 by Benjamin Minge Duggar. 1

But sure enough, Dr. George Armelagos, Professor of Anthropology at Emory University, proved conclusively that there was no mistake; tetracycline was in ancient bones, and in large quantities.

To be clear though, Armelagos was originally testing Sudanese Nubian and Egyptian bones dated between 350 A.D and 550 A.D., and later bones from a Jordanian site dating to the 2nd century B.C., not 3,000 year-old Egyptian bones. 2  Nevertheless, indirect evidence suggests that tetracycline could be found in Egyptian bones going as far back to pre-dynastic (pre-Pharaoh) Egypt (6,000 B.C – 3,100 B.C.). 3

Now, the curious story of how tetracycline was found in an ancient Nubian bone goes like this:

Around 1980, Debra Martin, a grad student of biological anthropology at the University of Massachusetts, was learning how to make thin sections of archaeological bones while visiting a research laboratory at Henry Ford Hospital in Detroit, Michigan.  After manually grinding down a bone fragment from a 4th century ancient Nubian mummy, Martin was preparing to view it under a standard microscope, but only a UV microscope was available.

Coincidentally, researchers in this particular lab were using tetracycline to measure the rate of bone formation because tetracycline tends to bind to calcium and phosphorus in growing bones and will emit a yellow-green fluorescence when exposed to UV light at the 490-nanometer wavelength. 4

Remarkably, when Martin looked at this ancient bone section under the UV microscope, it was emitting a yellow-green fluorescence, just like tetracycline.

Martin returned to the University of Massachusetts where she told Dr. Armelagos about her discovery, and in the fall of 1980, Armelagos, Martin and three other colleagues published their findings. 5

But Armelagos and his colleagues’ work was met with skepticism, so in 2010, he teamed up with medicinal chemist Mark Nelson and after using hydrogen fluoride to first dissolve the bones, they then extracted and finally positively identified the tetracycline through chemical analysis.  No question, tetracycline was definitively in the bones.

Of course the real kicker was that the levels of tetracycline extracted from the bones were so high it suggested that the ancient Nubians and Egyptians were consuming the antibiotic on a regular basis beginning in early childhood and on into old age. 6

Searching for the source of the tetracycline, Armelagos recreated many ancient recipes to no avail.  That was until he finally came across an ancient beer recipe from around that time, brewed it, and, lo and behold, the beer contained significant enough levels of tetracycline to be considered a likely candidate for the source of the antibiotic.

And Now, the Rest of the Story

Of course the documentary How Beer Saved the World left one big fat mystery sitting on the table: what the heck was going on with that ancient beer recipe that it not only produced antibiotics, but produced the antibiotics in such large amounts?

And here’s a scary thought: if ancient brewers were somehow introducing antibiotics into their beer, is it possible that brewers today are doing the same thing and pumping us all full of tetracycline?

Sure, a steady intake of antibiotics might keep us healthy in the short term, but ultimately it could also contribute to the increase of deadly antibiotic-resistant superbugs that might one day wipe mankind off the face of the Earth leading to a follow-up documentary: How Beer Destroyed the World.

But before you call the FDA, let’s examine the facts.

Like modern beer, the ancient antibiotic beer was made with grain. Naturally occurring tetracycline is produced by mold-like (spore-forming) bacteria called Streptomyces, which is common in soil and decaying vegetation, especially in warm arid regions like in ancient Nubia.  If these antibiotic-producing bacteria were to come into contact with grain, and that grain was then used to make beer, tetracycline would be in the final product.

Dr. Armelagos believes that the grains used to make the ancient beer were likely stored in mud bins, and because Streptomyces is commonly found in soil, the grains would have come into contact with the Streptomyces from the mud bins.

Now, even though modern grain is frequently covered with bacteria, it is normally stored in steel silos, not in mud bins.  This reduces the likelihood that modern beer would contain significant amounts of tetracycline.

But the mud bin theory only explains how the grain could have been contaminated, not how it was able to produce so much tetracycline.

For example, when grain covered with the antibiotic-producing bacteria was tested, there were only minimal amounts of tetracycline detected— not nearly the amount that was found in those almost 2,000 year-old bones.  So what gives?

Well, as Emily Sohn pointed out, “only when people fermented the grain would tetracycline production explode.”

But that explanation might leave some brewers scratching their heads, and here’s why: dead bacteria (Streptomyces) don’t produce tetracycline.  Allow me to clarify.

When making beer, malted grains are first soaked in hot water for about an hour.  That hot water extracts sugars from the grain.  The grain is then removed, leaving behind a kind of sugar water that brewers call “wort”.

After that, the wort is typically boiled for an hour or more, and then cooled.  Boiling the wort is key here because the boiling temperature would kill most bacteria, including Streptomyces.  It’s only after the wort is boiled and cooled that primary fermentation takes place.

In other words, if the Streptomyces bacteria are killed off during the boil, they wouldn’t survive to create any tetracycline during fermentation, certainly not the kind of levels of tetracycline found in those ancient bones.

You might then wonder how any tetracycline could be found in beer after Streptomyces-contaminated grain was boiled.  The reason that at least small amounts of tetracycline could remain after being boiled is because tetracycline doesn’t fully decompose until about 338 °F (170 °C), and boiling temperature is about 210 °F (100 °C).  Even pasteurization only seems to minimally reduce tetracycline levels by about 5-6%. 7

So, yes, tetracycline could survive the boil, but the Streptomyces bacteria couldn’t.  And we need that Streptomyces bacteria alive and well to make it to the fermentation process in order to produce the amounts of tetracycline found in those ancient bones.

Oh well- so much for our ancient antibiotic beer.  Eh, except for the fact that Dr. Armelagos and his colleagues were able to reproduce the ancient beer which was teeming with tetracycline, and he’s even had some of his student do it too.

The Secret Formula for Antibiotic Beer

Antibiotic Beer

The first thing you should know about ancient Egyptian beer recipes is that they are not exactly similar to how most beer is typically brewed today.  For example, the process for making Egyptian beer generally began first by making bread, which probably would have been made from emmer (a kind of wheat), spelt or barely grains, and there is evidence to suggest that the grains were malted.

In order to make the bread for an antibiotic beer the way the ancient Egyptians and Nubians seem to have done it, the Streptomyces-contaminated grain would go through a malting process which first begins by germinating the grain.

Anthropology student Amanda Mummert who assisted Dr. Armelagos in his research described the germination procedure like this: “This process is much like how you would do in a fourth-grade germination science project, where the grains would be soaked in water for about 24 hours, drained and then laid between sheets of cloth until they sprouted.”

Germinating the grain causes the starch inside the grain to be converted into sugars by enzymes which conveniently reside within the grain itself.  The grain is eventually dried out which stops the germination process, otherwise the sprouting plant would use up the starches and sugars in the grain needed to make beer.  

The dried grain is now called malt and contains the sugars that are important for making antibiotic beer.  Those sugars are important because they become a food source for the Streptomyces coating the grain to metabolize and convert into tetracycline.

After the grain was dried, it was milled into flour and mixed with water to create dough.  That dough was then left to rise which likely occurred as a result of exposure to naturally occurring yeast in the air.  During this time, the Streptomyces that was on the grain could produce even more tetracycline from the sugars in the fermenting dough.

The dough was then made into partially baked bread, and that bread was later tossed into water and allowed to ferment into beer.  Even modern beer recipes of villagers along the Nile today brew beer in this way, 8 and at least one ancient recipe called for taking three loaves of bread, breaking each piece up into quarters, and placing them into one crock to ferment. (By the way, fermentation is the process by which yeast consumes sugars and converts them into alcohol and CO2, which transforms our bready mush into beer.)

Even if the all of the Streptomyces would have been destroyed as a result of baking the bread, the tetracycline would have already been produced and been present in bread and any beer made from bread that used Streptomyces-contaminated grain.  However, Dr. Armelagos notes that the tetracycline bread was added to a broth of milled Streptomyces-contaminated malt, which would have further increased both the alcohol and tetracycline content.

In fact, Armelagos’ team preformed two experiments: one in which Streptomyces was added to the dough, and one where Streptomyces was added only to the malt broth.  The latter proved more successful, producing significant amounts of tetracycline.

The resulting “beer” may have been strained away from the mushy bread gruel, or simply consumed together in a bowl like a mildly alcoholic lumpy, beer-y soup.

So, as it turns out, the key to making ancient antibiotic beer is the presence of live Streptomyces bacteria during fermentation.  And if one were trying to introduce Streptomyces into beer or bread today (for scientific purposes), it is certainly possible to find the naturally occurring antibiotic-producing bacteria under certain conditions.  However, one could also probably just buy a pure culture of Streptomyces online and add it along with yeast early in the fermentation process (although personally, I generally prefer my beer antibiotic-free).

Final Comments

Although the ancient Egyptians and Nubians probably didn’t fully understand the science behind how antibiotics were being produced in their bread and beer, it does seem that they were aware of the medicinal benefits of such tetracycline-laced beer and used it as a mouth wash to treat diseases of the gums, as a dressing for wounds, as an enema, vaginal douche, and as Armelagos points out, as an anal fumigant where remaining dried grains were burned to create a smoke to treat diseases of the anus (your mileage may vary). 9

And finally, you may have wondered what were the effects of prolonged regular exposure to antibiotics for the ancient Egyptians and Nubians. Did it create a superbug that ended their cultures?  Well, Dr. Armelagos’ team wondered the same thing. “To test this, we have examined the bones in our sample for signs of periosteal reactions— roughened surfaces that form as a result of bone infection.  We have found no evidence that infections became more intense during the centuries represented by the bones, as would be expected if more resistant bacteria had evolved.” 10

To echo the late Paul Harvey: and now you know the rest of the story.


Hi, I’m Dan: Beer Editor for Beer Syndicate, Beer and Drinking Blogger, Gold Medal-Winning Homebrewer, Beer Reviewer, AHA Member, Beer Judge, Shameless Beer Promoter, and Beer Traveler.


1. Cartwright, A. C. (n.d.). The British Pharmacopoeia, 1864 to 2014: Medicines, International Standards, and the State (p. 193).
2, 8, & 10. Armelagos, G.J. (2000). Take Two Beers and Call Me in 1,600 Years . Natural History. Vol. 109/4
3. Mills, J. O. (1992). Beyond Nutrition: Antibiotics Produced through Grain Storage Practices, Their Recognition and Implication for the Egyptian Predynastic
4. Nelson, M., Hillen, W., & Greenwald, R. A. (2001). Tetracyclines in Biology, Chemistry, and Medicine (p. 219). Basel: Birkhauser Verlag.
5. Bassett, E., Keith, M., Armelagos, G., Martin, D., & Villanueva, A. (1980). Tetracycline-Labeled Human Bone from Ancient Sudanese Nubia (A.D. 350). Science, 209(4464), 1532-1534. doi:10.1126/science.7001623
Nelson, M. L., Dinardo, A., Hochberg, J., & Armelagos, G. J. (2010). Brief Communication: Mass Spectroscopic Characterization of Tetracycline in the Skeletal Remains of an Ancient Population from Sudanese Nubia 350-550 CE. Am. J. Phys. Anthropol. American Journal of Physical Anthropology, 143(1), 151-154. doi:10.1002/ajpa.21340
7. Kellnerová, E., Navrátilová, P., & Borkovcová, I. (2015). Effect of Pasteurization on the Residues of Tetracyclines in Milk. Acta Veterinaria Brno Acta Vet. Brno, 83(10). doi:10.2754/avb201483s10s21
9. W.J. Darby, P. Ghalioungi and L. Grivetti, Foor: The Gift of Osiris, 2 volumes, Academic Press, London, 1977.


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