Home Brewing an Ancient Beer
By Ed Hitchcock
Republished from BrewingTechniques' September/October 1994.
Intrigued by Anchor Brewing's reproduction of an ancient beer according to the Sumarian Hymn to Ninkasi, one home brewer set out to reproduce his own interpretation of an even earlier beer.
As both a paleontologist and home brewer, I could not help but be attracted by the media coverage of the reproduction of an ancient Sumarian beer. The beer, called Ninkasi after the Sumarian goddess of beer, was produced by the Anchor Brewing Company (San Francisco, California), based on a hymn inscribed on a clay tablet (1). Dr. Solomon Katz of the University of Pennsylvania and Fritz Maytag of Anchor Brewing worked to decipher the brewing clues contained within the hymn to reproduce the beverage so revered by the ancient Sumarians.
Apart from the sense of accomplishment in reproducing a piece of the ancient past, Katz and Maytag's work also added new information to an old debate. Anthropologists have long argued over whether beer or bread was the primary reason for the origins of agriculture (2,3). Katz and Maytag proceeded on the premise that an understanding of beer production methods of 4000 years ago could be used as a stepping stone from which to view the origins and evolution of beer. This, in turn, would provide a glimpse into the lives and cultures of the first nomadic tribes to settle into agrarian civilizations.
I decided to borrow their stepping stone and have a look into the past for myself. We know barley has been cultivated for at least 9000 years (4). I wondered what a beer of that era would have been like, a beer that is more than twice as old as the recipe reproduced from the Sumarian hymn. I decided to try some simple qualitative experiments in my kitchen. I managed not only to produce a beer that could have been made over 9000 years ago, but also to explore the intimate link between beer and bread. These experiments led me to the conclusion that the argument over the primacy of bread vs. beer is as academic as that of the chicken vs. egg.
THE DEVELOPMENT OF A PRIMARY INGREDIENTTo set the stage for the origins of beer, consider the other uses of grain. Undoubtedly the first use of grain, before either bread or beer, was to make gruel (2). Bread is effectively a cooked dense gruel and comes in three basic types. Unleavened bread, such as the tortilla, is the simplest form. It requires pulverized grain (flour) and water and is baked on a hot stone. It has a small volume and requires little in terms of ingredients. Leavened bread, with which we are most familiar, requires a large volume of flour, water, a source of sugars, and yeast. A third and less well known, bread is made from sprouted grains. The grains are sprouted, ground to paste, and baked in a loaf. The resultant loaf is very dense, sweet and cakelike, and is in effect a kilned malt.
One could argue endlessly on the basis of parsimony, culture, and archaeological evidence over the order of appearance of breads and beer. Whether sprouted bread was a derivative of sprouted gruel or unleavened bread may never be known. What we can be certain of is that people 10,000 years ago experimented with ways to consume grain. Somewhere in these experiments they discovered beer.
The question of how beer was discovered becomes academic. Beer may have been discovered through stewing sprouted bread, heating sprouted gruel, or unintentionally cooking grains that were stored in a damp place. Fermentation was most likely due to airborne microorganisms but may have been aided by the addition of fruit, raw grains, or other ingredients bearing surface yeast and bacteria. The serendipitous "accident" of making beer probably happened not once, but several times before the right blend of microorganisms produced a palatable beverage. I have no doubt, however, that once a pleasant tasting broth with euphoric effects was produced, word traveled fast.
ANCIENT BREWING TECHNIQUESHow was the beer made and what was it like? This question can be broken down into an examination of technology, ingredients, and procedures. The technology at the time of the origin of beer was not well developed but sufficient to make fire, tools of wood and stone, and a container of some sort. These are all it takes to make beer.
The main ingredient in beer is malt, which is a sprouted grain. Many grains can be and are used, including millet, corn, rice, wheat, spelt, and barley. We know from archaeological records that barley and wheat have been cultivated for at least 9000 years (4). Barley makes a poor bread because of its low gluten content, so we may safely assume that if people were brewing, they likely used barley and may have used wheat and other grains as well. The malt may have taken any of a number of forms. Dry malt may have been made for storage by either drying the sprouted grains in the sun, or baking sprouted loaves until hard. The very earliest beers may well have been made from raw sprouted grains that had undergone no drying or kilning.
The process for making the original beers was undoubtedly abbreviated compared with modern beers, which undergo separate mashing, boiling, and fermentation steps. The first beers likely underwent a continuous mash and fermentation. Sprouted grains were ground and mixed with water in a vessel of wood or even in skin bags. This vessel was heated either by fire, by dropping in heated rocks, or by setting it out in the hot sun. Fermenting flora would have been introduced from both the grains and the air. The fermented gruel could then be consumed, or the liquid could be drawn off as beer and the remaining grains and yeast mixed with wheat flour to make a leavened bread.
The fermentation of ancient beers would have involved many different yeasts and bacteria. The trick would have been to keep the pH down low enough to inhibit noxious bacteria. A "sour mash" process, in which the warm mash is inoculated with Lactobacillus from the grain husks, can grow some truly foul aerobic organisms if exposed to air. Presumably the "sour mash" portion of the fermentation was brief, or some acidity was built up during the sprouting process.
With the invention of ceramics, the process could be much more refined. The mash could be cooked over a fire, and the liquid could be drawn off and fermented separately. Eventually, techniques would have evolved to preferentially select certain strains of microflora by the addition of fruit, which bear yeast on the surface, or by using a "magic stick" to stir the wort and transmit yeasts between batches.
ANCIENT BEER, HOME BREWED IN MY KITCHENTo experience part of the ancient past, I wanted to reproduce an early beer. I decided to start with beer that could have been made with a mash cooked in clay pots. The idea was to sprout grains of barley and wheat, use some of the sprouted grains to make sprouted loaves, cook up a mash of sprouted grains and sprouted bread, and transfer the liquid and ferment it. To round out the experiment, I decided to collect the yeast sediment and any grains from the bottom of the fermentor and mix these with stone-ground whole wheat flour to make leavened bread.
Ingredients: I picked up the grains from a health food store. In addition to barley, I decided to include wheat and spelt for variety. Unfortunately, the barley was hulled. I knew the hulled barley could lead to problems but decided to take my chances for this first attempt.
To make the malt, I sprouted the grains in mason jars with perforated lids (these can be purchased at a health food store or made at home). I placed 200-250 g of grain in each 1-L jar and filled the jars with cold water, rotating them to ensure even wetting. I left the grains to soak in water for 24 h; I then inverted the jars and left them on a dish rack to drain. I rinsed the grains every 12 h and again left them to drain. After every rinsing I examined the grains for signs of germination. Germination was uneven, so the termination point was somewhat arbitrary; I stopped the sprouting when many of the acrospires had reached grain length and not too many had grown much longer. The wheat and spelt grains were ready in two to three days, whereas the barley took seven or more days to sprout sufficiently. By the time the barley was ready for use, the moist grains emitted a vinegary aroma, perhaps from the activity of bacteria in the grain bed.
I gave the grains a final rinse, drained them, and dumped those destined to become sprouted bread into a food processor for grinding (I could not find a mortar and pestle large enough). I emptied the resulting thick starchy paste of whole and partial grains onto a flat ceramic baking pan and formed it into "biscuits," 15-18 cm in diameter and 2-3 cm thick. These biscuits were then baked at various temperatures and times to observe the different results. I opted for flat biscuits rather than domed loaves because the flat shape would dry more thoroughly for better storage; the dome-shaped store-bought sprouted bread must be kept frozen to prevent mold from growing on the moist, sweet loaf.
I baked the biscuits at 120-175 °F (50-80 °C) for 8-18 h. Those baked at 150 °F (65 °C) for about 10 h seemed to be the most pleasant tasting. Those baked at lower temperatures (120 °F [50 °C]) remained sticky and pasty even after 12 h and required flipping and a further 6 h of baking. Those baked in a stepwise manner (130 °F [55 °C] for 1 h, 150-160 °F [65-70 °C] for 2 h, and 175 °F [80 °C] for 8 h) came out darkened to the color of dark Munich malt or British brown (porter) malt, depending on the original moisture content. The flavor of the wheat and spelt biscuits was better than that of the barley biscuits, though they all tasted of malt.
Recipe design: With biscuits and sprouting barleycorns, I set about trying to design a recipe that could be produced by people of 10,000 years ago and that could be reproduced easily and reliably. Ancient cultures undoubtedly experimented until they achieved desirable results. I chose not to reproduce all of these experiments, but rather to shortcut that process by calling on more modern knowledge of brewing science. I had to remind myself, though, that the experiment was to reproduce a fermented beverage of the ancients, and not to brew a competition beer from which I expected perfect extraction or crystal clarity.
Mashing: The mashing technique I finally settled on was a sort of decoction. The technique has the advantage of producing the desired temperatures without actually having to measure those temperatures with a thermometer. A half and half mixture of boiling mash and room temperature mash would give a temperature of approximately 140 °F (60 °C). If this resulting mash were slowly heated, it would pass through the starch conversion temperature range, through mash-out temperatures, and on to boiling. The extracted wort would be boiled, cooled slowly, and fermented.
Fermentation: Fermentation was another dilemma. I was not about to expose this wort to the microorganisms in my kitchen, which have been responsible for more than one spoiled batch of beer. And I did not wish to use commercially available lambic cultures, because I was not producing a lambic-style beer. Some have suggested that ancient beers were fermented with a combination of Saccharomyces and Schizosaccharomyces (5), but I had no local source of the latter. Instead, I recalled a portion of Katz and Maytag's interpretation of the Hymn to Ninkasi wherein they supposed that fruits, such as grapes (or raisins) or dates, may have been added, not as a flavoring but as a source of wild yeasts which normally live on the skins of these fruits (1).
I decided against using grapes to supply the yeast because fresh fruit is not readily available in Halifax in late fall. What is available has been shipped long distances and likely contains both pesticides and fruit fly eggs. I could have used a mix of pure wine and beer cultures to simulate wild yeasts, but instead I chose to culture the yeast from a batch of fresh unpasteurized sweet apple cider. This technique provided an inoculation with microorganisms known to produce fermentation without actually controlling the numbers or strains of those organisms. The beer was intended to be consumed young, so I was not overly concerned about spoilage or long-term storage. The recipe and procedure I settled on is shown in the accompanying box.
For those interested in specific numbers, the original gravity was 1.071 (much of it from dissolved starches). The final gravity was quite high as well - 1.033. As it fermented, the starch in suspension formed a pellicle on top of the kraeusen. As the foam fell, the starchy skin remained; its integrity was such that bubbles would collect underneath it, bursting only when they had grown to several centimeters in width. Much of the brown color of the liquid settled with the yeast as a starchy sediment as fermentation slowed, leaving a surprisingly pale liquor.
FINISHED BEER AND LEAVENED BREADAfter racking the beer into bottles, I performed the other half of the experiment. I removed a quantity (roughly 500 mL) of the yeast-starch-grain slurry from the bottom of the primary, warmed it slightly to rouse the yeast, and added stone-ground whole wheat flour to make a dough (about 1.5 L [6 cups]). After the dough was thoroughly mixed to a dense elastic texture, I left it to rise for 1 h in a warm place over the oven. I kneaded it, rolled it into a ball, placed it on a ceramic baking pan, and baked it at 350 °F (175 °C) for 55 min. The resulting loaf was dark and heavy and initially had a strong aroma of alcohol. The bread was hearty, though slightly bland from lack of sugar, oil, and salt. It was not unpleasant, and though not the best choice for a peanut butter sandwich, it would make an excellent vehicle for a ripe brie.
The beer was more of a surprise. My expectation was of a sour, yeasty, starchy brew, drinkable but not particularly enjoyable. Not so. The beer was quite pale and contained suspended starch, giving it the appearance of a Belgian White beer, though a degree or two darker. The level of carbonation was almost nil, though when poured with vigor a slight sparkling could be produced. Without carbonation it produced no head, so head retention was not an issue. The aroma was bready, yeasty, and cidery, with a hint of wheat. The cidery component was not like that of a beer made with too much sucrose, nor was it the acetaldehyde tang of a certain commercial American pilsner. The perception of yeastiness in the aroma faded after the first few sips. The flavor was soft and had a dry finish. No strong estery or phenolic notes were present, but a slight spiciness was detectable in the background. The high wheat content provided a bready character and may have contributed to the spicy note. The alcohol was noticeable, but not foremost. Despite the high original gravity, the beer was remarkably clean tasting. One taster compared it to Jade, a pale Flanders-style ale from the north of France, though I have never sampled this particular beer. It was good enough to warrant a second glass.
From this simple experiment we get a glimpse into the origins of beer and leavened bread. What was wholly unexpected in my results was that ancient beers may have been quite good, even by modern standards. The vagaries of wild fermentation would have precluded any form of quality control, and yet spontaneous fermentation with wild yeasts likely produced a pleasant end product often enough to keep the ancient brewers at their craft.
POSTSCRIPTAs a postscript to this experiment, buoyed by the success of my first attempt I decided to take one step further back: I wanted to reproduce the oldest beer. For this I would sprout barley in water, pound it into gruel, set it in the sun to mash, leave it open to the night air for inoculation, and see what happened. With any luck the sprouting grain and mash would be acidic enough to keep some of the bacteria at bay, and with even more luck I might pick up some interesting and inoffensive wild yeasts.
This idea, however, was misguided. I soaked whole feed barley in water, hoping that mold could be kept away by keeping the water level above the level of the grain. Within 36 h the concoction was churning and bubbling and dead weevils floated on the surface. After another 24 h, white mold was growing on the surface, and bacterial and yeast activity in the grain continued at a furious pace. I decided to discontinue the experiment. Between the putrid aroma and the fear of toxic molds, I decided perhaps I didn't want to taste this beer after all.
This test was not a complete waste, however. Though it should perhaps be repeated in a warmer climate, it indicated that the earliest beer was not likely produced by the simple accident of grain being soaked by rainwater. The earliest beers likely did not appear until some process for mashing or malting was developed, either in the form of a gruel or a sprouted bread.
ACKNOWLEDGEMENTSI would like to thank M. Snow and J. Pinhey for their comments on the ancient beer and T. Kavanagh for discussion and information.
REFERENCES(1) S.H. Katz and F. Maytag, "Brewing an Ancient Beer," Archaeology 44 (4), 24-27 (1991).
(2) R.J. Braidwood et al., "Symposium: Did Man Once Live by Beer Alone?" American Anthropologist 55, 515-526 (1953).
(3) S.H. Katz and M. Voigt, "Beer and Bread: The Early Use of Cereals in the Human Diet," Expeditions 28, 23-34 (1986).
(4) R.J. Braidwood, "The Agricultural Revolution," Scientific American, September 1960, 130-148
(5) J.X. Guinard, Lambic, Classic Beer Style Series 3 (Brewers Publications, Boulder, Colorado, 1990), p. 9.
Recipe for an Ancient BeerIn one pot mix:
500 g (dry weight) pulverized sprouted barley gruel
1 biscuit (~200 g dry weight) sprouted wheat or spelt bread
2 L of the last barley rinse water
200 g cracked winter wheat
In a second pot, mix:
Thoroughly break up the biscuits and allow them to soak. While the first pot soaks at room temperature, slowly heat the second pot to boiling. Once it has reached boiling, mix the contents of the two pots, and slowly bring the temperature back to boiling. With a wooden spoon, push the mash to one side of the pot and collect the liquid (plus any grain that happens to be floating around) with a cup and transfer it to another pot. Add 1 L of boiling water to the mash, stir, and repeat the pressing procedure. Repeat this until you have collected several liters of brown, gravy-like liquid, along with some grains. Bring the wort to a boil to sterilize it, cool, and pitch with your favorite wild yeast.
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