Past Orders: The Archaeology of Beer

current archaeology | www.archaeology.co.uk

IRELAND Bronze Age burnt mounds

July 2011 |28

AbovE Aerial view of the burnt mound at Ballyduff East, Co. Waterford, showing the wooden trough in which a saddle quern was found.A

nyone who has spent time on an excavation knows that archae-ology and beer go hand in hand. It is not just a cordial way for colleagues to wind down after a hard day’s work; archaeolog-

ical problems can also be calibrated according to how many pints must be drunk in order to solve them. A ‘one-pinter’ is easily figured out between rounds; a ‘five-pinter’ has few heads nodding in agreement – even after last orders. After the fifth pint, all logic breaks down.

It was whilst debating a ‘five-pinter’ – in this case, the function and purpose of Bronze Age burnt mounds – that Irish archaeologists Billy Quinn and Declan Moore hit upon a solution for

the most ubiquitous and mysterious Prehistoric monuments in Ireland. Perhaps, thought Quinn and Moore, burnt mounds were actu-ally microbreweries – an ancient reflection of a widely enjoyed modern pastime. The following morning, ‘The Great Beer Experiment’ was born.

Fulachta fiadh

Burnt mounds, or fulachta fiadh, are one of the most numerous type of sites excavated in Ireland, with an estimated 5,000 currently known to archaeologists. They are also one of the least understood. In Ireland, burnt mounds are usually found on low-lying ground close to water, though they also occur in fewer numbers

Past OrdersThe Bronze Age burnt mounds of Ireland are enigmatic, and many theories have been proposed for their purpose, from cooking sites to Prehistoric saunas. But were these monuments actually microbreweries for Bronze Age beer? brendon Wilkins samples the evidence.

the archaeology of beer

IMA

GE:

Hea

dlan

d Ar

chae

olog

y (Ir

elan

d) L

td a

nd Jo

nath

an M

illar

theories in the real world, learning how people lived, hunted, fought, or built. Whilst these techniques do not ‘prove’ that interpretations are correct, they provide a powerful tool in pre-dicting the type of evidence we should expect to see if the anticipated activities were taking place.

Using these principles, O’Kelly reconstructed the wooden trough and a hearth, and deter-mined that by heating stones in the fire and removing them with a long-handled shovel and then placing them in the trough, he could bring the water to boil within about 30 minutes. Using this (and occasionally adding more stones to keep the water boiling) he cooked a 4.5kg leg of mutton in three hours and 40 minutes. Once the meat had been consumed and the fires died down, the trough was cleaned out ready for reuse. It was about two-thirds full of cracked and broken stones, amounting to 0.5m3 in volume.

Chucking this material to the side of the trough, a horseshoe-shape mound began to form. Using these data to interpret the excavated evidence, O’Kelly estimated that as long as the

| Issue 256

in the uplands of Britain. Radiocarbon dating for these monuments varies significantly between the Late Neolithic and the Iron Age, with the majority clustering in the Bronze Age, between 1900-1500 BC and 1200-800 BC.

Burnt mounds are characterised by the pres-ence of a trough, into which hot stones were placed to heat water. Afterwards, the heat-shattered stone fragments were fished out of the trough and discarded, so that repeated use caused the gradual build up of a horseshoe-shaped mound. The trough could be rock-cut, wood-lined, or clay-lined, and was designed to hold enough water to boil or produce steam.

Whilst archaeologists have a good grasp of how this hot-stone technology worked, its purpose is less clear. Various interpretations have been proposed for the function of burnt mounds, including cooking, textile dying, cre-ating steam for sweat-lodges, and leather prepa-ration. The prevailing archaeological consensus is that burnt mounds were primarily cooking places, but this hypothesis is not without its shortcomings.

In 1952, the eminent Irish archaeologist M J O’Kelly undertook the first scientifically con-trolled excavation of two burnt mounds at Ballyvourney, Co. Cork. Burnt mounds had long been known to antiquarians; references in early Irish literature to the ‘open air cooking places’ of the young warrior-hunters of the fianna (small, independent warrior bands), led by the legendary Fionn MacCumhail, resulted in the burnt mounds being termed Fulacht Fiadh.

Professor O’Kelly found a standard pattern which included a mound of heat-shattered stones (measuring 12m in width and 60cm in height) surrounding a rectangular trough (mea-suring 1.8m long and 40cm deep). He found little in the way of artefacts or animal bone, an absence that is a tell-tale signature of burnt mounds. In order to investigate further, O’Kelly decided to employ the nascent science of experi-mental archaeology to determine whether these sites could serve as Prehistoric cooking places.

Burnt mounds as cooking places?

In his seminal book Archaeology by Experiment, John Coles set an agenda for a new approach to understanding the scant remains from the distant past. By reconstructing ancient equip-ment and technology using techniques avail-able in the past, archaeologists ‘try out’ their

bELoW Archaeologists excavating a burnt mound trough uncovered at Newrath, Co. Kilkenny, on the route of the N25, and directed by the author.

Archaeologists can only hope that when the Prehistoric party was over, someone had broken a few pots.

pho

tos:

Jam

es E

ogan

stones were not used more than once, the size of the mound at Ballyvourney would account for around 54 cooking episodes.

The experiment worked; and so, the inter-pretation of burnt mounds as cooking places passed into archaeology as received wisdom. The problem with this hypothesis, however, lies with the type of evidence we should expect to find if it were true. Burnt bone is rarely found at burnt mounds, which is surprising for a site whose primary purpose was seemingly to cook meat. This has been explained away by invoking the presence of acidic soils unfavourable to pre-serving skeletal material. Yet the mounds are one of the most excavated site types in Ireland (the author has personally directed excavations on eight burnt mounds, and assisted on at least twice that number), and a corrosive acidic envi-ronment cannot be claimed in every instance. The function of these sites was clearly still up for grabs. It was in response to this that Billy Quinn and Declan Moore proposed to undertake an experiment of their own.

The Great Beer Experiment

Quinn and Moore decided to investigate the possibility that the burnt mounds were brewing sites. Working with the same equipment one might expect Bronze Age brewers to use, Quinn and Moore also benefited from a 21st century understanding of science. They knew that water had to be heated to approximately 67°C in order for the starch in the malted grain to be turned into soluble sugars. They knew also that modern brewers achieved this by adding milled grain to the water to make a glucose-rich, syrupy sub-stance know as a wort, and that this mixture had to be transferred to storage vessels mixed with

yeast and flavourings, then left to stand for a few days, fizzing and frothing whist the active yeast devours the sugars and excretes alcohol. Most importantly, they knew that once this process had finished, and the fizzing had finally stopped, they would have an unhopped ale.

The basic ingredients of beer are milled, malted grain (barley or wheat), water, yeast, and a herb flavouring (usually bitter-tasting dried leaves to counter the sweetness of the brew). With all these readily to hand, the archaeologists set about preparing a trough (known to modern brewers as a ‘mash tun’) of similar dimensions to those found at burnt mounds, lighting a fire to heat the stones, and some earthen-ware fer-mentation vessels. They began by superheating stones on a wood fire for about two hours, before transferring them to the water trough.

They noticed that between 60°C and 70°C the water gently steamed, while the surface became glassy and mirror-still. An interesting note to this part of the process – thinking with a Bronze Age mind-set – was that in future experiments, done without the aid of a modern thermometer, Quinn and Moore knew that the critical temper-ature had been reached when their reflection on the surface of the water was clearest. They then added their wicker basket of malted barley, stir-ring vigorously, and over a period of about



July 2011 |30

IMA

GEs

: Moo

re G

roup

Ltd

.

21

Beer is more nutritious than bread, containing more vitamins and essential amino acids; some have even questioned whether beer, rather than bread, was the driving force of civilisation.

www.archaeology.co.uk | current archaeology| Issue 256 31

AbovE CLoCKWIsE 1. Heating the stones on an open fire for approximately 2 hours. 2. Billy Quinn gets the hot stones while Declan Moore checks the temperature. 3. Stirring the malt to transform it into a sweet, syrupy, workable wort. 4. The wort, ready to be transferred to fermentation vessels. 5. After the wort was placed in suitable containers, yeast and flavourings were added (suspended in a muslin bag) and left to ferment for seven days. 6. Demonstrating the brewing process to discerning friends and family.

3 4

5

6

45 minutes the starches were con-verted into sugars. At this point,

they placed more hot stones into the trough, bringing the syrupy wort to the boil, then trans-ferred the mixture into Bronze Age replica pot-tery vessels. After cooling, they added the yeast and seasonal flavourings – bog myrtle, juniper berries, and yarrow – before settling back as the mixture began to bubble.

The fermentation lasted about a week, after which the beer was ready for scientific testing. Quinn and Moore invited copious friends round to sample their Bronze Age brew, which was copper-coloured, with a sharp yet sweet taste.



July 2011 |32

Alcohol: essential ingredient of the primordial soupLast year’s celebrated Guinness advert – set to Sammy Davis Jr. singing The Rhythm

of Life – was a play on the brewery’s marketing strategy: the best things come to

those who wait. It featured three men in a pub taking a satisfying sip of Guinness,

before stepping backwards in time, devolving through each evolutionary stage to

become three bug-eyed amphibians – distant ancestors of our three drinkers –

sipping from a fetid pool.

The advertisers would have us believe that our pint was well worth the wait, but

how long exactly have we been waiting? What can archaeology tell us about the

invention of alcohol?

The first clear evidence for alcohol dates back 9,000 years, and has been recovered

in China by archaeologists using chromatography-mass spectrometry to find tell-tale

signatures for rice wine on fragments of Neolithic pottery.

Astronomers probing our galaxy have found that alcohol does not just exist on

Earth. A gigantic cloud of ethanol (Sagittarius B2N) has been detected near the

centre of the Milky Way some 26,000 light years away. It should come as no surprise, then, that

sugar fermentation (glycolsis) was the earliest form of energy production used by life on Earth.

Four billion years ago, single-celled microbes dined on simple sugars, excreting a mix of ethanol

and carbon dioxide: from the very beginning, carbonated alcoholic drinks were available on Earth.

It took slightly longer for complex organisms to make their way to the bar, but once they

had discovered the pungent, enticing aroma of fermenting sugars turned to alcohol by wild

strains of yeast, there was no turning back. The ‘drunken monkey’ hypothesis was proposed

by biologist Robert Dudley whilst observing Malaysian tree shrews’ penchant for binging on

fermented palm nectar. Early hominids would have been primarily fruit eaters, and it is entirely

possible that we evolved both a taste for alcohol, and livers capable of detoxifying after

overindulgence.

Without direct physical evidence, it is difficult to date the first intelligent production

of alcohol beyond the first pottery vessels of the Neolithic, but an enigmatic carving of a

woman holding a ‘drinking horn’ dating back 22,000 years led Patrick McGovern to develop

‘The Palaeolithic Hypothesis.’ Gathering ripe grapes in leather or wooden containers,

hunter-gatherers would have noticed the natural fermentation of the juices left in the

bottom. Recognising that this process could be speeded up by manually crushing the

grapes, and that the taste of aromatic liquid improved once left to settle, it is no great

leap to see our early ancestors developing a thirst for the good stuff.

IMA

GEs

: Don

Hitc

hcoc

k

AbovE Detail of possible drinking horn, with a series of 13 lines carved on it often interpreted as referencing the lunar cycle.

LEFt The Venus of Laussel was originally carved beneath a rock shelter in the Dordogne, holds a Bisons horn in her left hand.

The discerning palette could even detect a smoky caramelised flavour, imparted by the hot rocks. Although unlikely to win any CAMRA awards, the result was comparable to that from a home brew kit. The beverage could best be described as a gruit ale, an old-fashioned herb mixture used for bittering and flavouring beer, popular before the extensive use of hops.

The experiment was extremely successful, transforming 300l of water into 110l of ale with little effort; but, more importantly, it demon-strated that Bronze Age hot-rock technology could be used to brew beer. Thus, not only was the process of brewing beer in burnt mounds

feasible, Quinn and Moore had demonstrated that it was also extremely efficient. But how well did these new insights sit with what we already know about prehistoric drinking cultures?

Man cannot live on beer alone

Archaeologists can only hope that when the Prehistoric party was over, someone had broken a few pots. Pottery made it possible to ferment, store, and serve alcoholic drinks, and, most importantly, its porous fabric soaked up residues of the liquids once held inside. Interestingly, the earliest evidence for brewing is found in the same region as the earliest evidence for pottery. Archaeo-chemist Patrick McGovern analysed samples from early Neolithic pottery found in northern China along the banks of the Yellow River, and discovered residues of an alcoholic drink made from rice, grapes, and honey over 9,000 years ago.

In the ‘fertile crescent’ of the Middle East, Neolithic farmers were developing a monocul-ture based on barley. Alcoholic residues have been discovered from pottery vessels associ-ated with possible brewing pits in this region. Beer is more nutritious than bread, containing more vita-mins and essential amino acids; some have even wondered whether beer, rather than bread, was the driving force of civili-sation. Residues show, however, that mixed fermented honey mead was the most likely tipple of choice. As Neolithic cul-ture expanded westwards, coming into contact with native traditions and experience, brewers began to spe-cialise with different ingredients and techniques. This was the beginning of beer as we know it.

Burnt mounds date from the Neolithic, but the high watermark for their use was the later Bronze Age, sometime after western Europe came under the influence of the Beaker culture. This period is defined by the common use of a specific pottery style dating to the 3rd millennium BC. ‘Beakers’ have a distinctive bell shaped profile, and anal-ysis of Scottish examples from tombs at Ashgrove in Fife and North Mains in Strathallan suggest that the vessels contained a fermented drink – possibly a sweetened ale or mead. The spread of Beaker technology across western Europe was closely associated with increased barley cultiva-tion, which may also have been stimulated by the Bronze Age taste for alcohol. If Quinn and Moore’s Great Beer Experiment demonstrated that burnt mounds could be used for the pro-duction of beer, the wider Bronze Age context

showed that there was an appetite, and a demand. The only problem

now was finding the archaeological evidence.

A hiccup with the evidence

The Great Beer Experiment brewed a pass-able ale, but the proof of the pudding is not just in the drinking. The strength of an experimental hypothesis is under-pinned by what we find in the dirt; if

there is a general lack of animal bone to support O’Kelly’s cooking explanation,


Brewers began to specialise with different ingredients and techniques. This was the beginning of beer as we know it.

AbovE LEFt A burnt mound discovered on the N25 Waterford bypass prior to excavation, showing a large, wide, horseshoe shaped mound comprising black, heat-shattered stone. AbovE RIGht A burnt mound during excavation, with section baulks left in situ to assist in the discovery of the trough. bELoW This beaker vessel, found in Ciempozuelos, Spain, is typical of the form and style of the cultural pottery group.


July 2011 |

the archaeobotanical evidence to support the brewing interpretation is equally sparse.

Heading their detractors off at the pass, Quinn and Moore argued that spent grain would not have been disposed of by Prehistoric brewers, as it was still nutritious. Even after mashing in the trough, the grain could have been recycled to make bread, or given to animals as fodder. The by-product from the brewing process would also have been extremely vulnerable to micro-bacte-rial decay. Grain identified on archaeological sites has usually been charred during cooking or drying, but this would not have been used in brewing, as it would have spoiled the beer mash.

Even if botanical remains from brewing at burnt mounds had survived, they would not have lasted long before being consumed by animals, birds, and vermin.

We may also expect to find the tools associ-ated with brewing at burnt mounds, and in this regard archaeologists have been more suc-cessful. At Ballyduff East, near Waterford, Linda Hegarty discovered a saddle quern and rubbing stone deposited in a burnt mound trough (see photo left). The first stage of the brewing pro-cess would have required the barley to be malted by artificially germinating the cereal grains – placing them in a container in running water, then halting the process by drying with hot air. The malted cereal would then have been ready for grinding. By placing a handful of grains in the centre of the saddle quern, the rubbing stone was pushed back and forth to produce a rough-milled malt ready for the mash.

Past orders

Yet rather than solve the problem of burnt mounds, Quinn's and Moore’s experiment stimulated another round of discussion. Zooarchaeologist Auli Tourunen published an assessment of all the burnt mound evidence from a series of sites excavated on the N9/N10 Carlow Bypass. From 18 burnt mounds, a rigorous sampling strategy by Headland Archaeology (Ireland) Ltd recovered 1,346 pieces of animal bone, predominantly cattle. The anatomical distribution of these bones was consistent with primary butchery waste, sug-gesting that meat was processed, but not con-sumed, on site.

Other archaeologists have been quick to defend their own pet theories, and good evi-dence for both the sweat lodge (see box oppo-site) and textile interpretation have also come to light. With further research, we may be able to classify a number of types of burnt mound that represent a number of different functions, all based on the same hot stone technology. The Great Beer Experiment might not be the only explanation for all burnt mounds, but it is cer-tainly the most enjoyable.

souRCEbrendon WilkinsSenior Project ManagerWessex [email protected]

John Ó Néill, Burnt Mounds in Northern and Western Europe ISBN 3-639206098

Billy Quin and Declan Moore, Fulachta fiadh and the beer experiment Dining and Dwelling, National Roads Authority ISBN 978-0954595579

Patrick McGovern, Uncorking the Past ISBN 978-0520267985

REFERENCEs

ACKNoWLEDGEMENtsMany thanks to Billy Quinn and Declan Moore, of Moore Group Ltd.

bELoW The saddle quern discovered in a burnt mound trough at Ballyduff East. bottoM Detail of a wood lined trough at Ballyduff East.

Ca

IMA

GEs

: Sar

a N

ylun

d, B

rian

Mac

Dom

hnai

ll an

d H

eadl

and

Arch

aeol

ogy

(Irel

and)

Ltd


the sauna hypothesisLuxury spas are the current height of modern hedonism; time

spent at the spa is an escape from the trials and tribulations

of everyday life. It may come as a surprise that some

archaeologists think that burnt mounds represent their Bronze

Age counterparts.

Lawrence Barfield and Mike Hodder developed the ‘sauna

hypothesis’ to explain a series of burnt mounds they excavated

in the Birmingham area. Sweathouses are a consistent feature

in many cultures in the northern latitudes, with the Finnish

sauna being the best known. Drawing on ethnographic

parallels with Native American Indian sweat-lodges, they also

used experimental archaeology to demonstrate the viability of

their theory.

Recent excavation work in Ireland has identified

exceptionally well-preserved burnt mounds with clear

evidence for associated ‘sweat-lodge’ structures. Liam

McKinstry recently excavated a Bronze Age ‘bath house’ at

Annaholty, Co. Tipperary; and Caitriona Gleeson found the

clearest example thus far excavated of a sweat-lodge at

Rathpatrick in Co. Kilkenny, both for Headland Archaeology

(Ireland) Ltd.

The main feature at Rathpatrick was a 5m-diameter circular

structure with a sunken floor. Thirty six stake-holes were

found regularly spaced around the periphery, interpreted as

supporting a hemispherical, tent-like covering (hazel charcoal

had been recovered from the stake-holes – an ideal wood

for bending). The excavators suggested hot stones had been

heated on an adjacent hearth and then rolled into a pit within

the sweat-lodge. If water had been sprinkled on these stones,

it would have made an effective sauna. Once the occupants

had enjoyed their sauna, two steps led out of the structure

into an outside ‘plunge-pool’ where they could cool down.

The burnt mound at Annaholty measured 11.6m in length,

and 7.9m wide. It covered a 9m long feature cut into the subsoil

that contained a well-preserved rectangular wooden trough.

A stone-lined well was located at the north-eastern end, and

the entire feature had been made water-tight with clay and

stone walling. A similar ‘bath house’ was also found at Ballyburn

Lower (see illustration right) and Ballyhade. The major difference

between Annaholty and Ballyburn Lower was that there was no

superstructure above the trough, leading the excavators to the

conclusion that it was an open-air bathing site.

These sites may not be representative of all burnt mounds,

but they do show that many had more complex functions

than simply as cooking sites. Neither were they solely used for

personal hygiene. Sweat-lodges are known ethnographically

to be involved in complex rituals relating to rites of passage,

such as birth and death, and are a powerful tool for attaining

altered states of consciousness.

AbovE RIGht Artistic interpretation of Bronze Age bath-house and trough excavated at Ballyburn Lower. RIGHT Aerial view of the burnt mound at Annaholty, Co. Tipperary.

IMA

GEs

: Hea

dlan

d Ar

chae

olog

y (Ir

elan

d) L

td, u

nles

s ot

herw

ise

stat

ed

IMA

GE:

Sar

a N

ylun

dIM

AG

E: A

ir Sh

ots

Ltd.

IMA

GE:

Jona

than

Mill

ar

AbovE Artistic interpretation of Rathpatrick, Co. Kilkenny, based on site plans and photos. LEFt Bronze Age sweat-lodge, troughs and hearth at Rathpatrick.

Past Orders: The Archaeology of Beer

Documents

Transcript of Past Orders: The Archaeology of Beer