HBW: Xenophon Beer Experiment Returns!

This is a continuation of the much explored pulse-beer experiment that follows Xenophon’s description of an Armenian beverage in his Anabasis. For an overview of all previous posts (and the original passage), see below:

Xenophon Passage
Overview
Germinating and Drying
Brew Day (All Lentil Beer and Pseudo-Xenophon)
Fermenting and Tasting
Part 2: Grains/Pulses remaining in the Brew
Part 2: Fermentation and Tasting
Part 3: Spontaneous Fermentation (Brew Day)
A New Fermentation Technique?
Spontaneous Fermentation Check-in (3 weeks)
Tasting Pseudo-Xenophon Beer (6 months later)

Previously, I attempted a spontaneous fermentation of the 5:3:2 ratio of barley:wheat:lentils in an attempt to simulate more closely the beverage that Xenophon observed the Armenians drinking. It was thought that the lentils could only be digested by bacteria, not yeast (i.e. the bacteria that are found in the air). Unfortunately, this attempt was aborted due to the growth of mold in the beer. Since then, I have tried again with a slightly new process for the spontaneous fermentation and retried the experiment. With this new attempt, I wanted to test a hypothesis that the spent grains/pulses in the fermenting wort/beer could have been added to future batches to initiate fermentation.

Jan. 21 – Spontaneous Fermentation
OG 1.036 (original gravity) “wort” made with DME (dry malt extract) that was boiled in a mason jar

This wort was left outside in 41 degrees F (5 C) weather for an evening to cool. This evening was much “warmer” than the several previous weeks of below-freezing temps. My hope was that after the freeze there might be less airborne mold to contaminate the beer. The inoculated liquid was then covered and “stirred” for several days to ferment.

Jan. 29 – Check-in and Brew Day
The wort had, indeed, become inoculated with yeast and turned to beer. The beer reached its FG (final gravity) at 1.010.

I then brewed a version of “Xenophon’s Armenian Beer,” but anachronistically added hops for its antiseptic qualities. For this experiment, I do not find this addition problematic because the intent of this experiment is not to create a faithful facsimile of the ancient concoction. Recipe: 5:3:2 ratio of barley:wheat:lentils with 0.5 oz fuggles (left over). OG: 1.036. All grains were left in the wort for fermentation.

Fermentation

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The pellicle

The beer sat in my basement and fermented for several months. After the initial fermentation with the yeast, any floating lentils had sunk to the bottom of the bucket and a pellicle began to form slowly.

May 5 – Brew Day
I arbitrarily decided that the beer had fermented enough (actually, it was not so arbitrary – I was nigh approaching the moving-out date for my apartment). FG: 1.002. The beer smelled slightly tart and malty. The taste was of subtle apricots, strawberries, and bananas. Overall, the malt flavor was quite thin and there was only a slight hint of sourness.

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The spent grains/pulses (the liquid was drained before)

Before tossing the rest of the beer, I reserved half a mason jar of the spent grains/lentils. I then brewed a new beer: 1 lb barley (leftover Optic), 0.05 stale Czech Saaz; mashed in 1.5 g water. OG: 1.039. To ferment this beer, I added only the spent grains/lentils from the previous batch.

Fermentation

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Krausen after several days

Krausen developed within 24 hours. It was alive!

May 11 – Results

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Hydrometer reading of the FG

The beer fermented rapidly, reaching a gravity of 1.007 (4.2% ABV; 82% attenuation) by the time I had to pack and store all my homebrewing equipment. Lentils were also seen floating on the surface of the beer (just like Xenophon said!). Taste: The fruity esters were even more apparent in this beverage relative to the previous, and the malt backbone was assertive, though not distracting. This beer tastes like a somewhat weak Hefeweizen. I could drink this!

Conclusions
This experiment was certainly a success – the wort became beer simply by adding the spent grains and pulses that were left at the bottom of the fermentation vessel from a previous batch. For most ancient brewers (as far as we can tell), the precise nature of yeast was not well understood, and various methods have been documented throughout the world for inoculating wort – spontaneous fermentation, special vessels that retained the yeast in its uneven surface from previous batches, the use of dedicated, wooden ladles/rings/logs that held the yeast from previous batches. The genesis of this experiment came as I contemplated the purpose and presence of the grains that were left in the fermenting beverage (i.e. they were not strained and removed after the mash). Although this practice may have simply been a habit or tradition, it was likely maintained and perpetuated by some notion about the functional, ritual, symbolic, or other qualities of the grains/this method. Beliefs about the fertility, life-giving, and rebirthing properties of grain, in fact, are well-attested in many ancient populations.

Ancient people living in the Mediterranean were also very familiar with leavened bread and the use of sourdough starters. Thus, the addition of spent grains may be a natural extension or variation on this practice. Pliny the Younger, in fact, even talked about sourdough starters in a passage alongside a description of beer production (albeit nearly 500 years after Xenophon). Perhaps, the ancient Armenians used the spent grains/pulses as a sort of sourdough starter for the beer. This would be in keeping with a practice that was likely familiar to them with bread. Additionally, it could perhaps explain the use of the pulses in the beer. The barley was found to degrade quite rapidly in the fermented beer, but the pulses maintained their form after several batches. This allows the yeast cake at the bottom to mix with the spent grains/pulses and be retrieved for future inoculations. After several generations using this sourdough method, the yeast would have also acclimated itself to the specific recipe that the Armenians used and the conditions of fermentation, thereby producing a highly reliable and effective yeast.

Future Directions
I would like to repeat this experiment but re-use the spent grains/pulses-yeast mixture in as many batches as possible in order to see how the yeast adapts to my fermentation conditions. I would also like more control over the experiment by using a microscope and pH meter for each step of this process.

I should also test the viability of this method after the spent grains/pulses have dried in order to evaluate the storability of the yeast and spent grains/pulses.

Finally, I need to conduct significantly more research into the archaeological and archaeo-botanical evidence in ancient Armenia to evaluate my speculations.

 

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