Historical Brewing 201: OK, Sometimes, It’s as Hard as You Think

I’ve talked at you all before about how easy it can be to do historical brewing research and recreation. We often attempt to take the principles of period processing methods and attempt to translate them into modern methodology, to give  a sense of historical practice by varying the familiar.

We can also alter ingredient bills, to attempt to emulate the flavor profiles that may have existed at the time. This is all well and good, and it’s an important part of the process of experimental recreation.

Sometimes, though, the task is not so clear-cut, and attempting accurate recreation becomes a real challenge. How were the ingredients grown? What units of measurement were at play? Water quality? We can’t always answer all of these questions, but the attempt to do so can yield valuable information, and the process of extrapolating will teach us things whether or not we get a useful end-product.

So let’s talk about wood.

Wooden Bottle

(Archaeological Museum of Baden-Württemberg. Photo: Manuela carpenter – click for a link to the gallery page)

This bottle is part of an excavation of Trossingen grave 58, a find in Germany that dates to the 6th century CE. The picture above links to a gallery of the find.

This bottle is identified as a vessel with the remains of a hopped barley beer. This is sort of A Big Deal in the historic brewing world, because this would constitute the oldest existing physical evidence of the use of hops in a fermented beverage ever found. Not only that, but this is solid physical evidence of the use of hops a good 500 years before we had thought hops were really coming into use. This find has the power to really re-shape what we think of the history of brewing and hopped beverages. Neat stuff.

There is a publication which details the find (and its numerous artifacts) which you can obtain here; of course, the entire thing is available exclusively in German, so you may have to find a linguistically-inclined friend to help you out with it. Fortunately, I have some connections, and I managed to acquire the part of the journal detailing the bottle find. A bit of OCR, Google translate, dictionary consultation, and linguistically-inclined friend consultation, and I managed to figure out most of what the find was about.

Evidently, there was pollen residue in the bottle (~3500 grains), and researchers were able to identify the sources of the pollen grains:

Gut 17% davon stammen von Getreide, wobei der Gerste-Typ überwiegt. Getreideunkräuter machen zusammen fast 11% aus, Hopfen und die Weinrebe sind mit jeweils 0,4% vertreten. Mit gut 29% die größte und auch die artenreichste Gruppe sind Pflanzen…

If my translation is right, the contribution is 17% barley, 11% cereal weeds (possibly rye or oats?), 0.4% hops, 0.4% grapes, and 29% “bee pollen” (which is taken as a marker of honey). The bottle also contained evidence of fermentation (oxalate crystals), and so the author concludes that the beverage was probably a mixture of the above ingredients in the mentioned proportions, fermented together and hopped. The beer came first, and it was “enriched” with honey – or so the author concludes.

But I don’t like that analysis. For one thing, the author doesn’t seem to try to figure out the actual proportions of the plant matter represented by the pollen; the text seems to assume that all ingredients will convey the same amount of pollen, which may not be the case. They also don’t elaborate too much on their rationale for their experiments or on the type of hop present – which is too bad, because this is a pretty big find!

So let’s tear this down and show how you can extrapolate a recipe from scant information. What if you wanted to try recreating a beverage like this? No recipe, no method, just some pollen grains in a bottle – how can we do it?

Watch and learn.


That feel whenever you take off autopilot and try to land the science jet yourself.

When we do this kind of analysis, we often have to make lots and lots of assumptions and extrapolations. In archaeology, the variables are often well beyond our control – so experimental archaeology must try to control what it can or accept the limitations of uncontrolled variables. I’ve advocated a sort of “mapping” approach to redacting and analyzing ancient recipes, and that principle will aid us here as well; by listing out my assumptions and reasoning, I can go back and nitpick and refine and strengthen my arguments.

The goal here is to get to something that resembles a more accurate technique, and in the process to enumerate some other possible and plausible methods. Most of the time, these sorts of analyses are rarely definitive, and tend to leave us with more questions than when we started – but it helps us to focus our inquiries, so that our questioning can be more productive. This is the heart of science.

Let us assume:

1) That a total of 28% of the 3500 pollen grains are attributable directly to barley which has been malted (that would be 17% attributed mostly to barley and 11% attributed to “cereal” weeds – we know that barley is not generally insect-pollinated, so the “bee pollen” probably does not cross with this group);

2) That 29% of the pollen grains are attributable to raw honey (bee pollen shows up often in raw honey);

3) That 0.4% of the pollen grains are attributable to Hallertau hops (they’re alleged to be the first hops that were ever domesticated, and the Trossingen area was close-ish to Hallertau);

4) That 0.4% of the pollen grains are attributable to grapes (though as you will see shortly, I haven’t rolled grapes into my analysis yet because I can’t find information about them);

5) That the ingredients were fermented together in a single beverage (as opposed to the pollen contribution coming from, say, 3 different beverages which all touched the bottle at some point);

6) That a single kernel of barley (which contains three anthers) will produce ~4500 pollen grains, about half of which can be removed relatively freely – so ~2250 pollen grains will survive through malting and will make it into the final beverage;

7) That a single kernel of dry barley weighs one grain (0.06 grams – the origin of the term “grain” is the weight of one kernel of barley), and that malted barley is ~10% less dense than unmalted barley;

8) That raw honey contains, on average, 6000 pollen grains per gram (based on estimates of average pollen load of “normal” New Zealand honey);

9) That hops used were wild, and thus grew at a ratio of 1:1 male:female plants (hops are a dioecious plant, and wild-type examples of such plants grow in a ratio pretty close to 1:1 – this indicates that the pollen load of a male plant reported represents a single female flower);

10) That hops pollinate in a manner similar to their nearest botanical relative, Cannabis (note that hops are a cannaboid) – which produces an average of 36,500 pollen grains per male flower;

11) That the mechanism of wind pollination results in ~95% of the pollen accumulating on the windward (i.e. exterior) surfaces of the plant, and that this pollen load would be removed in hop processing (i.e. the pollen that didn’t make it into the interior of the female flower just falls off);

12) That there are 100 wet hop flowers (we use the female flower of the hop in brewing) per 50 grams of hops, or 0.5 grams wet per hop flower (which translates to roughly 0.1 grams per dried flower);

13) And that these estimates actually apply to 6th century German plants.


Y’know, I never noticed the completely incredulous look on his face until right now.

So, basically, I’m making shit up. “Educated guesses” if you’re feeling generous – but I’m basically winging it in the absence of any more useful information.

One thing that we can definitely see by my analysis so far: it is a great mistake to assume that all of the ingredients going into a beverage would have the same pollen representation per gram.

Let’s look at my numbers. Each barley grain produces 2250 pollen grains, each gram of honey has 6000 pollen grains, and each hop flower has 1825 pollen grains (5% of 36.5k). Let’s convert these to a standard measure: pollen grains per gram of plant matter.

Barley: 37.5k pg/g
Honey: 6k pg/g
Hops: 3650 pg/g

Now, how about the proportional representation of pollen grains in the find? 3500 pollen grains total, so:

Barley: 28% = 980 pg
Honey: 29% = 1015 pg
Hops: 0.4% = 14 pg

And then we just do the math to figure out the possible mass of plant matter that delivered that pollen load!

Barley: 0.026 g
Honey: 0.17 g
Hops:  0.0038 g wet (1/5 as much dried)

That gives us a ratio of barley:honey:wet hops (by weight) of 26:170:3.8, or to make things easier: 7:45:1

So let’s turn this into amounts that make more sense, shall we? Let’s also not forget that malted barley weighs 10% less than “green” barley:

63 g malted barley (about 2 oz)
450 g honey (about 1 pound)
10 g wet hops (2 g dried)

The first thing I notice straight away – this ain’t a barley beer. Not by any stretch. The mass of barley is so small that it really seems much more like a flavoring or additive than anything else. The vast majority of sugar here is coming from the honey – enough that I’d really call this a “mead.”

Of course, as you will remember, the word “beor” (which is a root of “beer”) is glossed with “hydromel,” which refers to a honey-based strong beverage. So really, it’s not outside the realm of possibility that one could call a honey-based drink a “beer” in the ancient world – it seems to have fulfilled that role.

In fact, the amount of barley is so small that I really think about a starter biscuit more than I do an actual source of grain sugar. Remember how I’ve been hypothesizing about Viking-era “breads” really being used as yeast starters? This may be the sort of thing I’m looking at here. And remember how I’ve talked about those same breads really being grain/herb mixtures? And how that grain/herb mixture, once fermented, could be used as the basis for fermenting a strong drink?

Pliny specifically discusses the various methods of making “leaven,” and one method is to incorporate grape must into barley flour and make a biscuit. Grape must incorporated into such a “bread” as I’ve talked about previously could explain the grape pollen in the original find. The use of herbs in the bread may give us a clue as to how the hops came into play; perhaps grape must and hops were mixed into barley flour, and the resultant “cake” was used as a yeast starter to then ferment a honey/water solution.

We can make a wide number of recipes simply by varying the amount of water that goes into such a thing. Generally, “hydromel” was a 1:4 honey:water ratio. A pound of honey occupies a space of about 10 fluid ounces, so we’d need about 40 fluid ounces of water to properly dilute that honey. Do that, add in your 65 grams of barley/dried hop mix (which has been previously fermented), and wait a bit. Yeast from the grapes eat those sugars, and you get a little more than a quart (about 1.5) of slightly hopped mead.

How hopped? Well, 2 dried grams of hops at that density of sugar yields ~12 IBU – roughly the same bittering content of Budweiser. For reference, an English Ordinary bitter is somewhere in the 25 – 35 IBU range. American pale ales are in the 50’s, and IPAs are up in the 70’s or more.

You could even add a bit more water – maybe go to half a gallon of final volume (1:5 ratio) with all that honey, which would give you a lighter-bodied beer with only 8  IBU. A little less sweet, a little less hoppy. The evidence still supports such an idea. Hell, it supports a lot of ideas.

Or you could go heavier (1:3 ratio) and make something really sweet with about 16 IBU. It’s all up to you and what you prefer!

Therefore, based on my analysis of the evidence, I conclude that the Trossingen bottle may have contained the remnants of a lightly hopped mead, which may have been fermented using the residue of a light grain fermentation.

Possible OG (Original Gravity) Range: 1.059 – 1.120
Possible bitterness (IBU) Range: 8 – 16
Possible volumes (quarts) Range: 1 – 2


The lesson here: archaeological evidence always requires interpretation. Using the same set of facts, we can come up with very different conclusions simply by varying the manner of our interpretation and the set of assumptions used to perform an analysis.

This is far from a definitive answer. I have thirteen listed assumptions, any variation on any of which can completely alter my outcome. I have no idea how much water was added, or how long it was fermented, or what proportion the grapes represent. We could re-analyze the model with an attempt to figure out what “cereal weeds” means and re-evaluate the contribution of plant matter from those (here’s a hint: rye produces ~10x the pollen that barley does – so there may be even less grain in this recipe than I’ve indicated).

But at least for now, I have something to work with – and that’s how science works.


So I killed a rooster and turned him into beer.

Behold the majesty of my cock. Yes, this post will be full of juvenile cock jokes.

Shockingly, though, I’m not interested in discussing my cock or its majesty at any…length…in this post. A discussion about the production of cock ale will probably be put up much later, so you will have to wait very patiently to sample my cock.


I promise, I’m an adult and a professional government employee. Really.

No, this post is a further examination of a topic I’ve already addressed. In a sense, I’ve already touched upon my cock – but it warrants revisiting.

You see, from time to time I still ask myself, “Self, why are we doing this? Why did this majestic cock need to die?”

I had a lengthy discussion with my good friend Phil (the expert cock handler pictured above) during the weekend where Death Cluck was slated to die; his extensive undergraduate education netted him degrees in Archaeology, Anthropology, and Medieval History. Yes, I mean 3 separate degrees. I don’t know about you, but I was a crappy student in my undergraduate career; that level of education is somewhat intimidating to me.

Yet, despite this intense level of education and intelligence, Phil expressed a sort of dismay at the general uselessness of it all. That no matter what, holding that cock seemed somehow more generally useful than, say, digging up some old pottery shards. That it wasn’t really making a difference. That it just seemed to exist in order to perpetuate its own existence.

We talked at length about our perspectives on the archaeology community and archaeology as a discipline, and we both take a similar view: it’s at best a weak science, and at worst a field of undisciplined and poorly-controlled speculation. Phil expressed a degree of regret regarding his choice of field – what good was it? Does it help anyone? Does it fix any global problems? The community seemed to consist of a circle-jerk telling itself that it was cool and valid and stuff – but what good is that? I found myself generally agreeing with his assessment.

True, as an elite member of the S.T.E.M. master race (to use the vernacular popular of the Internets), it’s easy for me to be dismissive of all those “lesser” disciplines that result in a B.A. or M.A. – or really, anything that awards an “A” as a degree. I have a lot of practice in being an arrogant prick, and even more practice in telling people why they’re wrong and need to re-evaluate their perspectives. A valuable asset to society, no doubt.

But I’ve pondered this more, and I’ve come to something of a conclusion.

Oh please, tell me more about the inferiority of the arts as a field of study.

I mean, OK, we study things because they’re cool. Sure. We dig up ancient artifacts and attempt to reconstruct history because it’s pretty nifty. Is it as “valuable” as curing AIDS or cancer? Probably not, but that’s a really unfair standard – and such comparisons lead to infinite regression or reductionist cycles.

AIDS is solvable with money – so if you’re not tackling novel influenzas, you’re not really helping. But y’know, viruses aren’t even the real issue – we need to improve the infrastructure of developing nations so that they can improve sanitation and thus get healthy. Aw hell, that really pales in comparison to the socio-political biases in the world that perpetuate those situations in the first place. But that doesn’t even matter because peak oil is coming, and everything is going to hell anyway. And none of that will matter if we can’t get off of this rock before we ruin it – so really, if you’re not a gazillionaire funding a ludicrous space colony program, you’re really not helping.

You see why such comparisons are silly? No matter your discipline, someone somewhere will find a way to tell you that it’s useless and you should be focusing on something that’s “more useful.”

Sure, we have to set our priorities and decide what things will get what amount of attention – but that reality doesn’t invalidate any particular field of study.

At its core, the discipline of archaeology is one of examination and investigation of very scant material. It is a necessarily outwardly-building discipline, because there is simply a lack of stuff to fill in any particular hypothesis. It proceeds in a direction somewhat opposite the typical path of science; whereas I take a complex system and break it down into fundamental components, archaeology looks at a component and attempts to extrapolate the system.

This is a very necessary component of critical investigation and knowledge-building. Yeah, we do that in science to some extent – but it’s never really on a big scale. The only reason we have any idea about dinosaurs is because some dudes way back when looked at some bones and said, “What if it was like this?” Good science? Not the best, but a useful thing. It examines and tests the exterior of our knowledge framework, while the sciences concern themselves with describing within that framework.

That outward framework building, fraught with errors and confirmation bias, is really the best way we know to expand our analytical framework. If someone didn’t push at the boundaries of what we can confidently know, we’d progress very slowly. Archaeology is a bit like engineering or architecture, except that it attempts to build a historical narrative of a society – it’s a field for dreamers who want to build new things. Sketch the framework and let the detail-focused people fill it in. Maybe the sketch has to change – that’s OK. The point is that while science is working at tiny level, carefully shading individual pixels comprising the image, archaeology (and other similar disciplines) is trying to outline the picture.

It’s also a way to teach people how to make decisions and formulate plans with little to no workable information. As a scientist, I can be stalled by a lack of information. Too many variables. Directions unclear. Ham-fisted cock joke. But because archaeology doesn’t hold itself to the same standard of verifiability, its adherents are more free to dream big dreams and come up with ludicrously complex ideas. Most are wild speculation, but hey – so are a lot of things.

The back-and-forth between strictly disciplined science and less disciplined investigative fields helps us to fully flesh out our understanding of the world – and that is an ultimately useful and noble goal. Any pursuit that is an attempt to usefully increase one’s knowledge or understanding of the world is a useful one, and the interaction with other people doing similar things allows you to make a very real contribution to the entire progress of humanity. It might not always seem direct, but there it is. And this interaction and the reconstruction of historical narrative helps pull us together – teach us more about our shared history, and we’ll feel even more connected to one another.

Seriously, why not? I mean, except for the whole “freezing to death alone on top of a mountain” thing. Also, cock joke.

Ultimately, the simple pursuit of understanding is a goal in and of itself. It might seem weak, but the truth is that pursuing knowledge because you think it’s cool is exactly what everyone does. People go into robotics because they’re fucking awesome. Prosthetics? Screw you nature, I’ma give this guy his legs back because we’re that awesome. Neurosurgery is amazing. Saving starving children in Africa? Bad-ass. Every single 5-year-old child loves dinosaurs because they’re so fucking cool, and in many cases that has lead those children to pursue careers in science. I can say confidently that I’m into biology because the T-Rex is approximately the most stupefyingly amazing thing we’ve ever discovered except maybe some sweet-ass planets. The image of the T-Rex mount at the American Museum of Natural History is burned into my brain, and that’s just fine.

Sure, we like to feel like we’re accomplishing something more than ourselves, but even that ultimately comes back to making ourselves feel good about who we are. Some people think that helping others is the coolest thing ever – and I’m hard-pressed to disagree. You’re accountable to yourself above all, and since you’ve got to be comfortable with yourself, I can’t see begrudging anyone their chosen passion.

Are you pursuing it because you love it? Are you connecting with the community? Are you taking opportunities to better yourself in pursuit of this thing? Yes? Then we’re all good.

We climb mountains because we can. We build progressively faster cars because we can. Tall rollercoasters, square watermelons, 50% ABV beers, chili peppers hot enough to physically burn your skin – all because we can.

So there’s the answer to the question. Why slaughter a chicken and throw him into beer? Why dig up 20,000 year old pottery and try to reconstruct the culture around it? Why perform open-heart surgery for 20 straight hours?

Yes, we can and should argue the particulars of what to pursue when, but the answer still stands:


Brewing with Egil: Now For Some Actual Brewing

I’ve destroyed vast swaths of whitespace and needlessly abused countless thousands of words in my endeavors to describe and explain Viking-age brewing.

I’m a scientist. Screw this “word” stuff. Let’s make something.

Bappir, anyone?

Pictured are the fruits of my labor so far – my interpretation of Viking-era “malt,” based on the research that I’ve done to-date. Let’s talk about how I got here.

As I’ve previously explained, I’ve drawn connections between the method for the processing of “polenta” described by Pliny the Elder, the method for producing “zythos” or “zythorum” described by Zosimos of Panopolis, and the analyses of actual bread finds from pre-1000 CE Scandinavia. I’ve also drawn inspiration from a recipe for “Ethiopian beer” documented by Olaus Magnus in 1555, which bears a striking resemblance to all of the other processing methods I’ve documented – and to the method presumably described in “A Hymn to Ninkasi.”

So, my method has borrowed from each source, in an attempt to extrapolate a speculative processing method.


Part I: The Grain Bill

First, this is how Pliny describes the ingredients of “polenta:”

But whatever the mode of preparation adopted, the proportions are always twenty pounds of barley to three (pounds) of linseed,4 half a pound of coriander, and fifteen drachmæ5* of salt: the ingredients are first parched, and then ground in the mill.

In Latin: “quocumque autem genere praeparato [vicenis hordei libris] [ternas seminis lini] et [coriandri selibram] [salisque acetabulum], torrentes omnia ante, miscent in mola

Note that the “drachmae” in the recipe is an interpretation of the original Latin “acetabulum;” according to Wikipedia, the “acetabulum” is a liquid or dry unit of measure with a capacity of 68 mL (1/8 sextarius). 1 tablespoon of salt (15 ml) is roughly 20 grams, which means we’re talking about roughly 90 grams of salt.

The “pound” to which they refer is the “libra” in Latin, which is the equivalent of 328 grams – or roughly  72% of a conventional modern English pound. Thus:

20 libra of barley = ~14.5 pounds = 6.56 kg = ~84%

3 libra linseed = ~2.15 pounds = 984 g = ~12.5%

0.5 libra coriander = ~0.30 pounds = 168 g = ~2.25%

Salt = 90 g = ~1.25%

Total mass:  7820 g

I decided to alter the recipe a bit, to make it a little easier to grasp (and to calculate ingredient amounts), and to standardize it a bit better so that I have a more solid platform for experimenting.

85% grain

10% oil seed

2.5% herb

2.5% salt

A healthy spread.

Of course, the Viking bread was not all-barley. The above-linked finds show that breads could contain barley, oats, and legumes – peas were the particular find.

In order to replicate such a bread, this is the final grain bill that I used:

Viking grain bill (proportions by weight) [500 g batch]

35% barley (un-malted, with husk) [175 g]

35% oats (steel-cut) [175 g]

15% peas (green, dried, whole) [75 g]

10% flax seeds [50 g]

2.5% herb (wild Icelandic thyme) [12.5 g – reduced to 4 g to account for dried herbs]

2.5% Atlantic sea salt [12.5 g]

What’s that? Wild Icelandic thyme?

Egil tested, dead men approved.

This was a gift from my younger brother from his vacation in Iceland. The thyme here is dried; since the directions specifically state that the ingredients have to be “parched,” I assume they were starting with fresh herbs. I reduced the amount of thyme used to 1/3 of what I calculated, to account for the difference between fresh and dried herbs.


Part II: Processing the Grains

Zosimos of Panopolis provides a fairly clear method for the processing of the grains, and subsequent conversion to the bread-like substance pictured at the beginning:

Take good pure barley and water, and soak it for a day. Spread it out and put it in a windy place for another day. Again soak it for 5 hours, then collect it in a sieve with handles, and soak it again after it has drained until it becomes puffy.

When this is done, dry it in the sun, until it deflates: The husk is indeed bitter.

Now mill (it), and make a bread-dough, adding leaven* as in bread-making, and bake it very well. Then boil it well, and separate the sweet water, straining it through a sieve.

Some heat toasted bread in a pan with water, and cook it a bit, but neither must he boil it nor heat too long, and taking it from the fire, transfer to other vessels, and again heat and reserve (the liquid).

*Note: According to Pliny, leaven was either made of must and grain, or fermented porridge, or a bit leftover from a previous batch – in other words, sourdough starters.

I am adapting this method 1) to account for the Viking-era grain bill I’ve identified and 2) to account for climatic differences between ancient Rome and very northern Europe.

First, we take all of the ingredients and steep them in water overnight:

Surprisingly, the liquid tasted pretty damn good.

Next, we “spread it out and put it in a windy place for another day.” In this case, I spread the soaked stuff onto a baking sheet and put it on my table with the ceiling fan running.

It smells and tastes better than it looks.

After this, we soak it again for 5 hours, and then drain it in a special vessel, and soak it some more. The archaeological record of the Vikings does not seem to have a “sieve with handles” in the way that Zosimos describes, so I just sort of sprinkled more water on the grain and left it out while I was at work (~7 hours).

Wow, that really sucked up the water.

The next stage is to “dry it in the sun,” until it “deflates.” Ultimately, this is a method for peeling the grain – soaking and drying will cause the husk to shrivel away from the grain, making separation easier. Now, northern Europe (especially Iceland and northern Scotland) is a cold, wet place. Drying in the sun is unlikely to work. That’s probably why there are so many corn-drying kilns in northern Scotland – they needed a way to dry out their wet grain. Keeping that in mind, I put the baking sheet in my oven at 275 F, until the grain was dried out.


Wow, that looks an awful lot like a high-kilned malt, with a bit of crystallized appearance. Hardly surprising, given the moisture content. Now, we need to “mill” the grain, add “leaven,” and bake the crap out of it.

Note to self: invest in rotary quern.

I did not have a proper Viking quern (hand-cranked two-stone rotary style – very laborious, but it makes flour), so I had to make due with my Barley Crusher malt mill. I ran the grain through 3 times to try to get it finely crushed, but it wound up being a fairly coarse meal.

I used the “boil some meal into a porridge and let it ferment” method of leaven. However, as I was on a time budget, I also added a pinch of baker’s yeast and a small dollop of the liquid from some plain yogurt. A sourdough is, after all, a symbiotic system of lactic acid bacteria and yeast – and Pliny’s methods of leaven would very likely result in a sourdough. Ideally, the starter would have been a bit of the dough leftover from a previous batch – but as I had no previous batch, this was not possible.

The “starter” was fermented overnight, then mixed in with the coarsely-ground meal and some water until it achieved a dough-ish consistency, and fermented overnight again. After that, I spread the dough mixture out into rounds ~6 cm in diameter and ~0.5 cm thick, and baked them at 300 F until they were rock-hard. See that first picture.

That gives us the Viking “malt.”


Part III: The Brewing

Little-known fact: Vikings invented the non-stick coating when they greased their frying pans with the rendered fat of burned villagers.

Zosimos similarly describes a method by which the bread can be processed into a beverage. However, I’ve identified two different speculative processing streams – one to make “brauð,” and the other to make the wine-like beverage “öl”. I’ve drawn my inspiration for the wine-like beverage from the work of Olaus Magnus, who described an “Ethiopian” beer made from sourdough bread mixed with water and honey.

For both products, I have used a 1:4 ratio of solid:liquid (by volume) in constructing my recipe. This is essentially the ratio documented by Magnus (effectively 1 part bread, 3 parts water, and 1 part honey), and is the ratio very commonly used in the ancient world for the production of mead. 16th century accountings of “ordinary” beer, such as the one described by William Harrison, also use a ratio of roughly 1:4 grain:water by volume (after accounting for differences in units in use at the time). Given that “ordinary” beer was intended as a common drink, I suspect this ratio may have echoes in a far earlier era, where processing methods had not yet evolved into totally separate specialized activities.

One of the biscuits I’ve baked occupies roughly 1/4 cup when crushed up.

For brauð: 8 biscuits were crushed and mixed with 2 quarts of cold tap water in a pot. The liquid in the pot is slowly brought to a boil (took about 1.5 hours) and boiled for ~5 minutes. The liquid is strained into another container, allowed to cool, and then poured into a jug.

For öl: The same essential method is used, though ratio varies a bit. 8 biscuits were crushed and steeped in 6 cups (1.5 quarts) of cold tap water – that’s a ratio of 1:3 biscuit:water by volume. As above, the mixture is heated slowly (~1.5 hours), brought to a boil, and boiled for ~5 minutes (until the protein foam subsides). This mixture was allowed to cool in the pot for ~30 minutes before being strained as above; the warm-to-the-touch liquid was poured into a different jug, and 2 cups of local raw honey were poured into the jug. The jug was shaken to ensure that everything was dissolved.

Why raw honey? Because while the Vikings had honey and apiary technology, they did not have the high-pressure filtration methods we have today. Any honey they used would have been full of pollen and wax. This particular honey has the comb removed, but still contains pollen – and also wild yeast and/or bacterial spores. Raw honey will ferment at about 17% moisture, so this will be an excellent vehicle for promoting wine production.

Both jugs have been left on my counter with the tops open, to promote a sort of open, wild fermentation. The saga of St. Olaf talks about ale being ladeled from an open cauldron into cups – indicating that fermentation was probably carried out in open containers. In the case of brauð, they may have simply left the liquid in the pot in which it was first cooked, or they may have transferred it to another vessel as Zosimos recommends.

These will be fermented (well, hopefully they’ll ferment!) until Saturday, where I’m teaching this whole thing (plus the entire Brewing with Egil series) as a class at the East Kingdom Brewing University this Saturday.


Summary of Process

1) Assemble the grain bill: 35% barley, 35% oats, 15% peas, 10% flax seeds, 2.5% herbs, 2.5% salt. Steep ingredients in water for ~24 hours.

2) Spread out grain and place it in a breezy location for ~24 hours.

3) Re-water the grain and allow it to stand for ~8 hours.

4) Dry the grain by low direct heat (an oven set to 275 F, for example).

5) Grind the grain into a coarse flour/fine meal.

6) Mix the meal with a sourdough starter (ideally a bit left from a previous batch) and some water, and allow to ferment overnight.

7) Form the fermented dough into cakes ~6 cm in diameter and ~0.5 cm thick. Bake at ~300 F (again, relatively low temperature) until they are dried and hard.

8) For brauð, use 1 biscuit in 1 cup of water. For  öl, use 1 biscuit in 3/4 cup water. Crush the biscuit(s) into the water and slowly bring to a boil over a gentle heat.

9) Strain the liquid into an appropriate container. For  öl, add 1/4 cup of honey per biscuit to the liquid once it’s cooled (but still warm enough to dissolve the honey).

10) Ferment for ~3 days, and enjoy!


Commentary, Limitations, and References

There are a few notable limitations in this method. First, of course, is that this is all still speculation on my part. There is no written method for the production of these beverages, and it’s unlikely that we’ll ever find one.

My 4 primary process limitations are: 1) lack of a proper rotary quern to produce flour, 2) lack of a proper period corn-drying kiln fired by appropriate fuel, 3) lack of a proper period baking setup to replicate the heat profile, and 4) lack of proper period-traceable ingredients.

A minor limitation was my lack of fully-soured leaven, but this is partly related to having a proper flour, and is generally trivially rectified by simply giving myself more lead time to allow the starter to ferment properly. As for the rest, in order:

1) While I cannot obtain an artifact rotary quern, instructions for making a facsimile using poured cement and pie plate tins exist online. While still not a truly period material, this would provide a flour with a more proper consistency. This is a project for the future.

2) The simplest corn-drying kilns are little more than fancy holes in the ground, dug in a two-bowl style. I am in the process of planning a reproduction of such a kiln; this will enable me to dry the grain using a proper fuel. Research indicates that, in addition to local hardwoods, Icelanders used sheep dung as a fuel source. This would produce a very smoky fire, which would impart a smoky taste to the dried grain.

3) Some archaeological evidence suggests that Viking bread may have been baked on iron pans or directly on burning coals. Given the small size of the extant finds, this seems plausible. Other evidence points to earthern ovens being used at the time. Both methods will be attempted and the results compared side-by-side. This is another experiment which will be attempted in the future.

4) Traceable ingredients are difficult to obtain. A variety of barley called Bere has been examined and traced to the Viking age (and earlier); however, Bere is native to northern Scotland, and importing it is difficult. A small group in western Canada also grows Bere, but the cost of exporting a sufficient amount is prohibitive. I will, in the future, either grow Bere or suck it up and shell out for it. Native oats are easier to obtain, and green peas are mostly unchanged.

It’s worth noting that salt in the Viking age was very very likely produced by being poured over burning wood (a method documented by Pliny as being practiced by the Germanic tribes), which would produce an alkaline, smoky product. My salt research is a completely separate topic, but will definitely have an impact here.

So, I am increasingly confident in my conclusion about Viking-era beer brewing. Now that I have established a baseline method, I can begin experimenting with different elements of the process, in an effort to make them more “period.” However, I believe that my current method is a reasonable representation of a product that likely existed in the Viking age.


  1. Pliny the Elder. Naturalis Historia. Perseus Digital Library. http://www.perseus.tufts.edu/hopper/text?doc=Plin.+Nat.+toc

  2. Magnus, O. A Description of the Northern Peoples. trans. Peter Fisher and Humphrey Higgins, ed. Peter Foote, 1996 Hakluyt Society. (originally published 1555 in Rome.)

  3. Zosimos of Panopolis. De Zythorum… trans Gruner CG. 1814. http://archive.org/stream/zosimipanopolita00zosi#page/n3/mode/2up

  4. “Ancient Roman units of measurement.” Wikipedia article. http://en.wikipedia.org/wiki/Ancient_Roman_units_of_measurement (I know, I know. Wikipedia. I double-checked the sources and they seem legitimate.)
  5. Scott, Sir L. “Corn-Drying Kilns.” Antiquity. Vol. 25. Num. 100. pp 196 – 208. Antiquity Publications Ltd, 1951.
  6. Harrison, W. Elizabethan England. From A Description of England. Ed. Lothrop Withington. Project Gutenberg. Released 30 May 2010. EBook #32593. London: Walter Scott. http://www.gutenberg.org/files/32593/32593-h/32593-h.htm



I figured I should add in some pictures of the stuff fermenting. I would up adding a pinch of Munton’s dry ale yeast, just to get the stuff going. Turns out, my apartment doesn’t contain enough wild yeast to start a fermentation. Next time, I’ll just leave the stuff outside.

On the left, we have brauð – the basic beverage used as a food. This one has “fermented” for about 5 days now – longer than was likely typical. However, it’s still a light fermentation, and a stable beverage; the flavor profiles at day 3 and day 5 are the same. It tastes something like a small beer crossed with a broth/stock flavor; it also has a very pleasant citrus-like brightness to it. Almost lemony, actually. This may be a result of the interaction between the wild thyme and the fermentation.

On the right, we have öl. This has some alcohol content at this point, and is the only one of the two with some carbonation. It is, however, quite sweet – it tastes like mostly un-fermented mead. This one may become more alcoholic (and balanced – it’s really damn sweet) with time. I definitely see how something like this could be glossed with “hydromel.”

Paying it Forward

So I wound up not having as much time as I thought I would this weekend – so no new content this week.

That frees me up to advertise someone else.

Waaaaaaaay back, when I first decided to start exploring Viking-era ale production, I ran across some archaeological work by a woman named Merryn Dineley. She’s done a lot of work on Neolithic brewing, and her thesis is one hell of a read. This work is a very large part of what inspired me to dive into this research, and I’ve had the pleasure of communicating with Merryn about her work over the past year or so – digging into the nitty-gritty of unearthing ancient brewing techniques.

Together with her husband Graham (a craft brewer of many years’ experience), they’re working on reconstructing a vision of ancient brewing all the way through the Viking age.

Some of you Facebookers may recognize those names – they recently published a poster summarizing their work in researching Viking brew houses. It’s been making the rounds on Twitter and such – I guess that’s what happens when you tell a bunch of archaeologists they’ve been wrong for years!

It’s funny – in my perusal of many archaeological publications, I’ve been largely underwhelmed by the “understanding” of brewing in the archaeological community. It’s pretty clear to me that the vast majority of these researchers aren’t brewers, and they very frequently don’t understand the science behind the process. Many of these papers are riddled with unfounded or erroneous conclusions, and there is insight to be gained with a more complete scientific understanding.

Merryn and Graham know their stuff. Their work is very interesting, and if my blog interests you, check out theirs too.

And if you’re really interested in experimental archaeology, you should check out the Experimental Archaeology Conference.