2000 'Neolithic Ale: Barley as a source of sugars for fermentation' more

Chapter 13 in ‘Plants in the Neolithic and Beyond’ edited by Fairbairn, A., Neolithic Studies Group Seminar Papers 5, Oxbow Books, 2000 Neolithic Ale: Barley as a source of sugars for fermentation Merryn Dineley & Graham Dineley “Our prehistoric fathers may have been savages, but they were clever and observant ones....the art and practice of the brewer are founded on empirical observation....the brewer learnt from long experience the conditions not the reasons for success.” John Tyndall, extracts from a speech on Fermentation to the Glasgow Science Lectures Association, October 19th 1876 INTRODUCTION The preparation and the consumption of food are important aspects of prehistory that can provide a valuable insight into the daily life of people in past societies. Around 4000 BC in the British Isles people began to cultivate and process cereal crops and to keep domesticated animals. This paper addresses the question of why Mesolithic communities in Britain began to cultivate, in particular, the barley grain during the early Fourth Millennium BC. Cereals are generally believed to have been a primary source of carbohydrate in the prehistoric diet, being useful for making bread, porridge and flour. This may well be so, but they are also a source of sugars, sweet malts and malt extract that are delicious to eat, an excellent source of B-vitamins in the diet and that are also the prime ingredient for the manufacture of ale. With a minimum of equipment and the right knowledge, it is easy to make malt extract and subsequently ale from the grain. This paper proposes that the British Mesolithic cultures were interested in these products and that this was a major factor in the decision to cultivate and process cereal crops. It is generally agreed that the consumption of alcoholic beverages was an important aspect of life in the British Isles during the Second Millennium BC (Burgess & Shennan 1976, Sherratt 1991). There have been a number of discoveries of cereal-based organic residues in Bronze Age contexts that have been interpreted as being the remains of fermented alcoholic drinks. The most well known example, radiocarbon dated to c1540 BC, was found in a beaker at North Mains, Strathallan, Fife on the east coast of Scotland, at the site of a timber circle and henge (Barclay et al 1983). The beaker was in a well-sealed Bronze Age cist, hence the unusual survival of the organic material, and it accompanied the skeleton of a young woman. Merryn Dineley and Graham Dineley Other examples include the residues found in a beaker accompanying a skeleton in a stonelined cist at Ashgrove, Fife, in eastern Scotland, where the presence of pollen from immature lime flowers (Tilia cordata) and meadowsweet (Filipendula vulgaris) indicates a fermented honey drink, mead. Similar residues have also been found in birch bark containers at Bregninge, Zealand and at Nandrup Mors, Denmark (all referred to in Dickson 1978) and these all indicate the presence of a mead-type drink. Residues identified as wheat chaff, cranberries and bog myrtle (Myrica gale) and found in a large birch bark bucket at Egtved, Holland (Dickson 1978:111) suggest that it had once contained a cereal-based fermented alcoholic drink, ale. In recent years, similar organic residues have been discovered on Neolithic pottery sherds at ritual and domestic sites in Scotland and on Orkney. At Kinloch Bay, on the island of Rhum, residues were noted on fragile sherds of Neolithic pottery and a radiocarbon date of c1940 BC was obtained (Wickham-Jones 1990). Analysis showed low counts of cerealtype pollen and high values of Ling (Calluna vulgaris), Royal Fern (Osmunda regalis) and Meadowsweet (Filipendula ulmaria). Attempts to re-create the brew by William Grant & Sons were, apparently, successful and quite palatable. During excavations at the ceremonial site of Machrie Moor, on the Isle of Arran, sherds of Grimston-Lyles Hill and Grooved Ware pottery were noted to have organic residues adhering to them (Haggerty 1991). Later analysis showed that they contained cereal pollen and macro plant remains perhaps the residues of either mead or ale. At the Neolithic and Bronze Age ceremonial centre at Balfarg/Balbirnie, Tayside, Scotland (Barclay et al 1993), cereal-based residues were found on sherds from very large Grooved Ware vessels that had been buried in pits. The residues contained pollen from several plants including Meadowsweet, Henbane (Hyoscyamus niger) and Deadly Nightshade (Atropa belladonna), an interesting mixture of additives that might indicate ale with hallucinatory properties. Recent research has, however, failed to replicate the pollen results (Long et al 1999). The most recently discovered example of barley residues were again found on Grooved Ware vessels, this time at the settlement of Barnhouse, close by the Stones of Stenness, Mainland Orkney (Richards and Jones forthcoming). Given such interesting finds, the possibility that cereal processing activities during the Early Neolithic of the British Isles included malting, mashing and fermentation must be considered. Ian Hodder has recently argued for the “destabilisation of ‘taken-for-granted’ assumptions in the interpretation of archaeological data” and for the need to look at material cultures as a whole (Hodder 1997:695). Our research, experimentation and investigation onto aspects of Neolithic cereal processing techniques takes this approach, with the emphasis being on the manufacture and not on the consumption of sweet malts and ale. THE CONVERSION OF GRAIN INTO SWEET MALTS AND ALE People have been successfully making fermented alcoholic drinks from malted barley, rye and wheat grain for several millennia (Katz and Voigt 1986; Samuel 1995,1996), but the scientific explanation for the biochemical processes involved in malting, mashing and fermentation was only discovered in the late 19th century, when the pioneering experiments of Louis Pasteur [1822-1895] revealed yeast to be a living organism, causing Neolithic Ale: Barley as a source of sugars for fermentation fermentation by bio-chemical reaction (Pasteur 1879). John Tyndall [1820-1893] continued these investigations, showing that anaerobic conditions were necessary for an alcoholic fermentation to occur (Conant 1952). Such conditions are straightforward to create and beer or ale can be successfully fermented in a large bucket with a suitable lid (Figure 1) or within a closed vessel, such as a glass demijohn or a wooden barrel. Until the scientific discoveries of Pasteur and Tyndall in the 19th Century, maltsters and brewers were not aware of the complex biochemistry that was involved in the conversion of barley grain into sweet malts and ale. They knew what to do but not why. There has always been a magical and mysterious aspect to the complexities of the brewing process. Allowing the grain to germinate just a little makes it slightly sweeter, more palatable and much easier to grind or crush with quernstones (Katz & Voigt 1986). The process of germination activates certain enzymes which begin to convert the grain starch into malt sugars and malt flour. Once the grain has been germinated any subsequent heating with water will re-activate the enzymes and produce a sweet product, not a starchy porridge or gruel. The processing required to convert grain into ale is actually a sequence of three different biochemical reactions that occur during the stages of malting, mashing and fermentation. Each stage requires its own quite specific conditions and minimal equipment and installations are sufficient to successfully make ale, as is explained in detail below and summarised in Table 1. Table1: The conversion of barley grain into sweet malts and ale Merryn Dineley and Graham Dineley PROCESS Malting: germination in controlled conditions (12-15 days) Mashing: saccharification or conversion of starch to sugars (several hours) Sparging (several hours) Hot water Boiling (several hours) Fermentation (temperature dependent, it usually takes several days) Sweet wort Herbal additives to flavour and/or preserve Concentrated wort with added flavourings and preservatives Yeast Barley mash or Barley cakes Baskets or sieves Large and small vessels Syphons (reeds?) Heatproof and waterproof vessel or container Hot stones Large, deep vessel with a suitably wellfitting lid Access to a reliable water supply Washing facilities for sticky equipment Hearth INGREDIENTS EQUIPMENT Harvested, threshed and winnowed barley grain and water Crushed, malted grain Water Porous bag or a watertight vessel Rakes or shovels BUILDINGS & INSTALLATIONS Level malting floor in a Grain Barn Hearth or kiln PRODUCTS & RESIDUES Dried / parched malted grain Carbonised grain Barley mash with sweet malt liquid , barley cakes Burnt barley cakes or mash Sweet wort Sludgy residues of barley chaff Spent grain Concentrated wort with added flavourings and preservatives Ale Sludgy residues of barley chaff with pollen, plant material and yeast Calcium Oxalate Quern Hearth or kiln Bowl or mash tun Hot stones Hearth/Fire to provide ambient warmth Table 1 provides a summary of the necessary ingredients, equipment and installations for the conversion of barley grain into sweet malts and ale in a Neolithic context. The only waste products are accidentally carbonised grain from the malting or mashing processes and sludgy residues resulting from the sparging or fermentation processes. The biochemical reactions involved in the conversion of cereals into sweet malts and ale are unchanged across the millennia. Therefore, experiments in brewing methodology are valid and will produce a similar product to that made in the past. Sumerian brewing methods have been described in the ‘Hymn to Ninkasi’, which is an ancient text dated to c1800 BC and, using this ancient inscribed text as a recipe, a Sumerian-style ale was successfully made by researchers in association with the Anchor Brewery of California (Katz & Maytag 1991). It was aptly named ‘Ninkasi’ after the Sumerian goddess of brewing. More recently, researchers from Cambridge University have worked in association with Scottish and Newcastle Breweries to make a re-created Egyptian Ale which they named ‘Tutenkhamun’ (Samuel 1995). Neolithic Ale: Barley as a source of sugars for fermentation Our home is, in effect, a domestic brewery since one of us (Graham Dineley) regularly makes 6-8 gallons of beer at a time. He uses the ancient and traditional techniques, mashing the crushed malted barley and then extracting sweet wort by sparging the mashed barley with hot water. This wort is then boiled with hops and fermented into ale using 5 gallon plastic buckets with lids. Our initial intention was to investigate the techniques and equipment of the maltsters and brewers of Bronze Age Britain. Graham was sure that he could re-create the ‘Strathallan Brew’, ale flavoured and preserved with meadowsweet instead of hops. With the benefit of his skill and experience in brewing, we embarked upon a series of mashing and fermenting experiments. Using 1 - 1.5kg pounds of crushed, malted barley grain purchased from a brewing suppliers we used traditional techniques to make about a gallon of Meadowsweet Ale. MAKING A BARLEY MASH OR CAKES Malting: the controlled germination of the grain. According to descriptions from Early Christian Ireland (Comey,1996), malting usually takes between 12 and 15 days. The grain is first steeped in water for 2 or 3 days to start germination. If this is done in a vessel then the water has to be changed regularly in order to prevent spoilage of the grain. A more straightforward method is to put the grain in a bag and simply leave it in a stream for the required time (Flett, pers comm). The process of steeping activates enzymes within the grain that convert starch into sugars, the food source for the growing plant. The soaked grain is then spread out on a level floor, preferably within a building for protection from the elements and potential predators and to provide an even temperatures for the grain to grow. It requires regular watering and raking to maintain the necessary moisture levels and to prevent moulds from developing and thus spoiling it. If growth were allowed to continue too far then all the grain starch would be converted into sugars by the enzymes and used up by the growing plant. So, growth must be stopped at an early stage and this is achieved by parching or drying out the malted grain in a kiln or oven. Malting methods have not changed over the millennia. The difference between modern and ancient malting techniques is one of scale only, with maltsters today dealing with much greater quantities of grain than their prehistoric ancestors. Mashing: the conversion of the remaining grain starch into malt sugars All of the remaining grain starch can be converted into sugars by the enzymes within the grain - a process known as saccharification. In order to achieve a better extraction of the sugars it is a good idea to lightly crush the malted barley prior to mashing, a task easily accomplished in prehistory using quernstones or grinding stones. Crushing or cracking the malted grain also produces a small quantity of malt flour. The trick of the mashing process is to get the grain to digest itself into malt sugars. At around 65-67 degrees Centigrade, in the presence of abundant water, the dormant enzymes are reactivated and complete the conversion of starch into sugars, a process that is largely complete after 10 minutes and finished within a few hours. A slow-rising temperature favours this conversion into simple sugars (Line 1980) and the ancient techniques described below would certainly have provided such conditions. Today, modern breweries can control both water and mash Merryn Dineley and Graham Dineley temperatures with precision, but it seems that the prehistoric brewer had equally efficient methods of mashing. MASHING EXPERIMENTS We have so far investigated three techniques, using crushed pale malt from a brewing supplier. The experiments and results are described below. Baking barley cakes in an oven The Sumerians and the Egyptians baked a sweet barley cake or malted bread, referred to as bappir in Sumerian texts (Katz and Maytag 1991). We mixed malted crushed barley with water to make flat cakes and left them in a very low oven for several hours. There was a distinctive aroma when the cakes reached the required temperature for saccharification. It was the same aroma that accompanies a mash using modern methods, that is, striking the malt with hot water to achieve a final mash temperature of between 65 and 67 degrees Centigrade. The conversion of starch into sugars was obvious, with the barley cakes changing colour from pale to dark brown. They tasted sweet and they had a coarse, husky and granular texture, more closely resembling crunchy muesli biscuits than modern white bread or cakes. Baking barley cakes on hot stones: We built a hearth surrounded by flat stones on which we baked the bappir when the stones became hot to the touch. The saccharification was successful and the cakes had to be kept moist throughout the cooking. It took several hours to complete the conversion. Mashing barley in an earthenware bowl on an open fire: We mixed the pale, crushed, malted barley with plenty of water in an earthenware bowl that had been previously treated with beeswax to make it watertight. We heated the white, starchy mixture gently in the warm ashes of a fire. Constant monitoring of the mash temperature was essential to prevent overheating in the early stages. This was done by hand, with the precise temperature being checked with a brewing thermometer. More water was added to cool the mash and the bowl was removed from the fire if the mixture became too hot. Saccharification began within a few minutes and was completed within a few hours. The maintenance of a steady, low mash temperature required some skill but, nevertheless, the mash was successful, resulting in a sweet, caramelised and very sticky mixture of almost whole barley grains, together with a dark brown malt liquid. It looked more like a bowl of cooked granola than pale-coloured porridge or gruel. This dark brown, sweet-tasting barley mash contrasts with the pale crushed malt and water that were the initial ingredients. All of the grain starch was converted by enzymes into sweet malt sugars. During mashing, the barley grains remained whole and some were burnt onto the sides of the bowl. The liquid produced by a bowl mash is pure malt extract. This is an excellent source of B-vitamins and it is delicious to eat, a nutritious product in itself. It can be consumed on its own or mixed with milk to make a delicious, sweet malted drink rather like Horlicks and rich in B vitamins. In the Middle Ages and in later times, brewers used fire-heated stones to heat the crushed, malted grain with abundant water in large wooden mash tuns (Comey 1996). Slavomil Neolithic Ale: Barley as a source of sugars for fermentation Vencl (1994) describes similar mashing methods that were used in Carinthia until earlier in this century. Hot stones were used to heat up the water and malted grain “in wooden bowls until it caramelised” (Vencl 1994:310). We have not yet tried this method, but we are sure that it would work well. MAKING ALE FROM A BARLEY MASH OR CAKES Sparging: obtaining a sweet wort for subsequent fermentation. More sweet liquid or ‘wort’ can be easily washed out of the barley mash or cakes with hot water and this technique is known in the brewing trade as ‘sparging’ (Line 1980,141ff). The amount of water used roughly equates to the desired gallonage of wort. We tried using a basket as a sieve over a large vessel, as is illustrated in the Theban tomb painting (figure 2) and this worked well, albeit slowly. We also used modern methods, that is, cloth grain bags with an integral sieve placed inside large plastic buckets. We used plastic tubes to syphon off the sweet wort into a clean bucket (figure 3). The resulting wort is very murky. It is actually a suspension of the barley chaff which soon settles to the bottom of the storage vessel as a brown sludgy residue, leaving a clear, dark brown, sweet liquid above. Careful transference of this liquid from one vessel to another is possible, but spillages often occur and the wort is extremely sticky. Syphoning is the best method of separating the sweet wort from the sludgy residue. Access to water is a crucial aspect of this stage, as everything gets sticky and needs to be washed! The contents of the basket or sieve after sparging is known as the ‘spent grain’ and it is not a waste product. It remains slightly sweet and it makes an excellent animal fodder, unsparged barley mash being far too sweet and rich to use. Boiling the wort with additives for flavouring and preservation of the ale. Boiling the sweet wort kills the enzymes that are still active and also concentrates it. Hops are nowadays added during the boil for flavour and they function as a preservative in beer (Corran 1975). Hops, cultivated and used in Europe since the 8th/9th centuries AD were not fully accepted and used by British brewers until the 14th/15th centuries AD. In prehistoric and medieval times many other herbs, such as Meadowsweet (Filipendula vulgaris) and Bog Myrtle (Myrica gale), were used by brewers to both flavour and preserve their ale (Vencl 1994). In our experiments we used dried meadowseet flowers collected from Orkney in a recipe based on the Bronze Age beaker residue find from Strathallan, Fife (Barclay et al 1983). We found that it acted as an excellent preservative as well as being a flavouring of the subsequent ale. It also gave the ale a reddish hue. A test batch of barley ale made without the addition of meadowsweet during the boil went sour within two or three days whereas that made with added meadowsweet has remained fresh and drinkable for months. Fermentation: the conversion of sugars to alcohol. Alcoholic fermentation requires anaerobic conditions (Conant 1952), easily achieved by placing a lid on the fermenting bucket. Yeast thrives in room temperatures of 12 to 30 degrees Centigrade and, under such conditions, it converts the sugar of the wort into carbon dioxide gas and alcohol (Line 1980, 163). The yeast can be introduced to the wort in several ways: Merryn Dineley and Graham Dineley 1. A portion of yeast sludge from the previous brew can be used to start the next brew, but after 3 or 4 occasions it can become spoilt by bacteria. 2. Yeast cultures can be kept alive and added to the wort in order to start the ferment, but again are prone to bacterial infection. 3. The wort can be started by airborne yeasts and, in Belgium, lambic beers are still made in this way. 4. Dried yeast keeps well and, using scanning electron microscopes, it can be seen on the interior surfaces of Egyptian fermentation vessels of the Second Millennium BC (Samuel 1995, 1996). The addition of a sweet wort to such a pot would re-activate the yeast, thus beginning a fermentation. 5. In the Western Isles of Scotland, a hazel ‘wand’ was traditionally used to stir brews during fermentation. When a fresh wort is stirred, the yeast dried on the ‘wand’ would start it fermenting. A vigorous ferment can be a spectacular sight. The wort appears to boil without the application of heat as the yeast produces bubbles of carbon dioxide that rise to the surface (Line 1980:163). After fermentation, a brown sludgy residue settles out at the bottom of the vessel, containing yeast, cereal chaff and traces of any herbs added during the boil. The ale is a clear dark brown liquid which can be siphoned off or carefully poured into a clean vessel. It is then ready for consumption. Meadowsweet Ale We made a flat, uncarbonated Meadowsweet Ale using the equipment and methods that are described above. Members of Manchester University Archaeology Society first tasted it in 1996 and some was also taken to the Neolithic Studies Group Conference at the British Academy, London, in March 1998. Descriptions of its taste varied, with some people likening it to a barley wine and others comparing it with mead. Most comments were favourable. NECESSARY EQUIPMENT AND MATERIALS TO MAKE SWEET MALTS AND ALE Barley, wheat and other cereals are versatile crops and they can be processed in a number of different ways. Most of the archaeological literature appears to make the assumption that cereals were a source of carbohydrate in the prehistoric diet, being used to make flour, bread, porridge or gruel but, as our experiments have shown, barley grain can also be easily processed into malt sugars and subsequently ale. The processes of malting, mashing and fermentation require simple ingredients together with minimal equipment and installations. All types of cereals are suitable, such as wheat, barley, oats and rye and the basic requirements for ale production have been assessed as being grain, water, vessels, fuel and yeast (Vencl 1994:307). Slavomil Vencl’s analysis can be expanded upon in the light of our experiments (Table 1). A building with a malting floor is also necessary and a hearth, oven or kiln is needed to dry out the malted grain. Facilities for washing the equipment are also required - cleanliness is a crucial aspect of brewing and such activity is a strong source for ritual behaviour. Watertight and heatproof vessels are also needed. Bowls are suitable for mashing and boiling and large deep buckets are perfect for storage, sparging and fermentation. Without doubt, some of the most crucial aspects of brewing are the skill, knowledge and experience of both maltster and brewer in processing the grain correctly in order to make a successful brew. Some elements of the brewing process, Neolithic Ale: Barley as a source of sugars for fermentation both organic and non-organic, may survive in the archaeological record. These are included in Table 1 and are discussed in detail in the following sections, together with examples of relevant finds in Neolithic contexts. INGREDIENTS, PRODUCTS AND RESIDUES The ingredients are grain, water, herbal additives and yeast. The products of the malting, mashing and fermentation processes are ephemeral - people would have consumed the sweet malts and the ale and the spent grain would make an excellent animal feed. There are potentially three ways that ingredients and products can survive in the archaeological record. Grain may be charred during the malt drying or the mashing stage and would therefore be found as carbonised grains or as burnt barley cakes or a burnt mash. Malted grain is difficult to distinguish from unmalted grain, since it only needs to be slightly germinated for the necessary starch-converting enzymes to have been activated. Two types of sludgy cereal-based residues may also be preserved; barley chaff from the sparging process; and a barley residue with yeast and herbs or pollen that settles out during fermentation. Carbonised grain Carbonised grain is often found during excavations at sites of the Neolithic within the British Isles. For example, it has been found in the middens of the Neolithic settlements at Skara Brae, Orkney (Childe 1931) and at Knap of Howar, Papa Westray (Ritchie 1983). A failed kilning or drying of the malt might be the explanation or the grain may have been burnt or charred during the mashing process, after which it was thrown away. Carbonised grain may also be the result of an accidental fire of the building where the grain was being stored or processed and this may be the explanation for a discovery of about 20,000 carbonised grains of emmer wheat and naked barley at Balbridie, Kincardine, Scotland, where post holes indicate a huge rectangular timber building (25 metres by 12 metres) constructed in the early Fourth Millennium BC (Fairweather and Ralston 1993). The two cereal types were found in different parts of the site, indicating different kinds of processing activity - the manufacture of bread and of sweet malts, perhaps. The remains of another, much smaller, rectangular timber building (15 metres by 5 metres) has been excavated at Lismore Fields, Buxton, Derbyshire and here a wide range of plant fragments have been identified, including a large number of carbonised grains and barley chaff (Garton 1987). The proximity of both buildings to a reliable water supply, the River Dee at Balbridie and a natural spring at Lismore Fields, would have provided the necessary water for the malting, mashing and sparging of the grain but whether or not an ale was also being made at these sites is much more difficult to assess. Barley cakes or mash Finding the remains of barley cakes that date back to the Neolithic on a site in the British Isles seemed, at the time of the presentation of this paper, a most unlikely prospect. However, since then, it appears that such a find has occurred in a context dated to c36203350 BC. At Yarnton (Robinson, this volume), two fragments of organic material, measuring about 7 x 5 x 5mm, were noted at the site of a substantial rectangular post built structure. The fragments comprised “partly crushed cereal grains, one of which could be discerned as barley (Hordeum sp), in a vesicular matrix.” The interpretation suggests a Merryn Dineley and Graham Dineley barley ‘bread’, made from coarse or coarsely ground grain and the description correlates well with the barley cakes that we made, as described earlier. If the grain had been malted prior to baking then, as our experiments show, the result would inevitably be a sweet product, like a malty, granular barley cake. Sludgy residues Evidence for the manufacture of ale in the Neolithic has been found as residues on pottery vessels. Those residues found at Kinloch bay, Rhum (Wickham-Jones 1990), Machrie Moor, Arran (Haggerty 1991) and Balfarg/Balbirnie, Tayside, Scotland (Barclay et al 1993) have already been briefly discussed in the introduction and, in each case, excavators interpretations of the residues included the possibility of ale and/or mead. Of these three examples, the most convincing evidence for the manufacture of ale in the Neolithic comes from the Balfarg ritual site, where the residues were on sherds from very large Grooved Ware vessels that were deliberately deposited in pits. Descriptions of the burned organic material, both in the original analysis (Moffatt in Barclay et al 1993:109ff) and in the more recent re-examination of the residues (Long et al 1999), make interesting reading. Three categories of burned material were originally identified by Brian Moffatt, these being amorphous and burned material, amorphous, granular and burned and burned cereal mash. He describes “a cereal-based preparation that was coarse and crude” with an incomplete process of homogenisation and the pollen and seed fragments being fairly well intermixed. Although the existence of Henbane (Hyoscyamus niger) seeds within the residue has not been confirmed by recent re-analysis (Long et al 1999), the residue was described as “a uniform and well processed substance, possibly something like a thick carbohydrate or protein based gruel” (ibid:50). This description is consistent with the sludgy residues that accumulate at the bottom of a fermentation vessel, that is, a well processed homogenous mixture of cereal chaff, pollen, plant fragments and seeds. Tiny amounts of beeswax were identified among 15 of the 31 samples originally analysed by Moffatt and this might reflect the practice of waterproofing the vessels to contain a liquid ferment. If Henbane, Hemlock and Deadly Nightshade were among the additives to the brew at Balfarg, then a very interesting practice was going on there. According to Culpepper, these plants are all highly dangerous and fatal if they are consumed in large quantities. Henbane has some medicinal properties, such as the alleviation of earache, if applied externally as a tincture. If consumed in small quantities, Henbane induces intoxication, hallucinations, blurred vision, rapid heartbeat, euphoria and dizziness (Barclay et al 1993:110). It is well known as the plant that induces perceptions of flying and it has long been used by witches (Sherratt 1996). Using the method of Gas Chromatography/Mass Spectrometry, evidence of barley, sugars, cattle milk and cattle meat has been recently found on very large Grooved Ware vessels at Barnhouse, a settlement of the early Fourth Millennium BC close by the Stones of Stenness and the Ring of Brogar on Mainland Orkney (Richards & Jones forthcoming). In structure 8, Barnhouse, barley chaff was found in the complete Grooved Ware vessel that was found set into the ground up to its rim (Jones pers. comm.). Such a location in the ground would, in theory, provide a suitably even temperature to sustain a yeast/barley culture. House 2 was used for grain processing, with evidence for the removal of husks (ibid). Neolithic Ale: Barley as a source of sugars for fermentation Calcium Oxalate Deposits of calcium oxalate, which is also known in the brewing trade as ‘beerstone’ always accumulates on the internal surface of any vessel, whether ceramic, plastic or metal, that is used regularly for the fermentation or for the storage of a fermented barley product such as ale or beer. It ultimately causes a characteristic white scale over the entire inner surface of the vessel. The earliest evidence for such an encrustation has been discovered on large pottery vessels at Godin Tepe, a Bronze Age site in the Zagros Mountains of Iran dating to the 4th Millennium BC (Michel & McGovern 1992). Calcium oxalate has not yet been identified on any ceramic vessels from sites in the British Isles. EQUIPMENT Any tools or equipment necessary for mashing and brewing that were made with organic materials, such as bags, baskets, sieves, wooden bowls or rakes/shovels would not survive long in the ground (Table 1). Quernstones, ceramic vessels and heat-cracked stones would survive but they may not always be recognised as the equipment for malting, mashing and brewing. Querns or rubbing stones are usually interpreted as a tool for grinding the grain into flour to make bread but they are also ideal as tools for crushing the malted grain prior to mashing. Ceramic bowls are a suitable shape for making a barley mash and also for boiling a wort. They would need to be watertight and so they may have been treated with beeswax or fats. In our experimental work, we did this by gently heating an earthenware bowl and then melting beeswax into the fabric of the warmed pot. The wax easily soaked in and it made the bowl much more robust and watertight for cooking purposes. Animal fats could also be used, the process being the same as with beeswax. Modern ‘chicken bricks’ have to be similarly treated or ‘seasoned’ with fats before use. Therefore, any waxy or fatty residues found on or within the fabric of ceramic vessels may reflect this kind of treatment rather than the potential contents of the pot. Large, deep bucket-shaped ceramic vessels, preferably with well fitting lids, would be suitable for several aspects of the brewing process. They could be used for storage, steeping, sparging and fermentation (figure 6). Smaller ceramic vessels would, of course, be ideal to eat and drink from! Ceramic bowls and buckets It is important to consider the potential function of a pottery vessel as well as its decoration and categorisation into pottery styles or types. Ceramic bowls of many decorative styles are often found in association with the remains of timber structures dated to the Neolithic and may perhaps indicate cereal processing activity, such as mashing the malted grain or boiling a wort. Grooved Ware pottery is bucket-shaped and, if fitted with a lid, it would make a perfect fermentation vessel (figure 6). At Skara Brae, Mainland Orkney and at Rinyo, Rousay many such large and highly decorated vessels were found and there were also many stone pot lids, some measuring up to two feet wide (Childe 1929,1930,1938). Stuart Piggott first identified this style of pottery in the 1930s and called it ‘Rinyo-Clacton Ware’, reflecting its widespread use throughout the country (Piggott 1931:73). It is now always referred to as Grooved Ware and it has been found at numerous settlement and ritual sites of the Neolithic throughout the British Isles. Grooved Ware pottery can vary in Merryn Dineley and Graham Dineley size from small drinking cups to large, deep bucket-shaped vessels. For example, at Raigmore, near Inverness in Scotland a great many Grooved Ware sherds were found in association with a rectangular timber building. The rim diameters ranged in size from 140mm to 460mm (Simpson 1996). Excavations at the huge henge of Durrington Walls (Wainwright and Longworth 1971), a site not far from Stonehenge, revealed several tonnes of Grooved Ware sherds, some representing very large vessels (figure 6). Durrington Walls has recently been identified as a place of ritual behaviour and feasting during the Neolithic (Albarella and Sarjentson 1997). This activity probably included the manufacture and the consumption of ale as well as the consumption of roasted pig. Grooved Ware has been found at many nearby Neolithic ritual sites, for example, The Sanctuary, Avebury, Stonehenge and Woodhenge. The the ritual consumption of ale during the Neolithic is a distinct possibility in these contexts. BUILDINGS AND INSTALLATIONS Necessary installations include a malting floor, which could be made of beaten earth, clay, plaster, wood or stone, within a building. Evidence of regular repair and levelling might indicate the use of a floor for malting. A hearth, kiln or oven is needed for drying the malt, for mashing the malted grain and also to provide the ambient heat for fermentation. The malts and sugars make this kind of cereal processing activity a very sticky business, so Neolithic Ale: Barley as a source of sugars for fermentation access to water and washing facilities for pots and people are another essential (Table 1). It could be said that a building where the harvested grain was stored, winnowed, threshed, malted and then further processed into sweet malts and ale, functioned primarily as a Grain Barn, although it may have had a number of other functions for the local community at other times. Rectangular timber buildings The interpretation of timber buildings on the basis of groundplans and post holes alone is a very difficult proposition. A Grain Barn is only one of many potential and possible functions for a Neolithic building. Other possibilities would include use of the structure as a dwelling place, a storehouse, a workshop, an animal shelter or as a place for community activity and ritual celebrations. Among the vast number of circular and rectangular timber structures that existed in Neolithic Britain (see Darvill and Thomas 1996 for full details), two rectangular timber buildings stand out as having definitely been involved with grain storage and processing activities, these being Balbridie and Lismore Fields, discussed earlier in the context of carbonised grain finds. Both of these large rectangular timber buildings were used to store and process quite large amounts of grain but, unfortunately, the poorly preserved floor surfaces and the lack of any surviving structure above ground makes a clear interpretation difficult. Within the structure at Lismore Fields there were several hearths set between what appear to be divisions into separate workspaces or areas (Garton 1987). The building at Balbridie was similarly internally divided, but unfortunately, the flooring has been destroyed by heavy ploughing in recent times and no evidence of hearths, ovens or kilns has survived the passage of time. The stone buildings of Neolithic Orkney On the Orkney Islands, buildings in the Neolithic were constructed from the local stone and therefore the structural evidence for the manufacture of sweet malts and ale is much clearer there. Skara Brae is situated at the Bay of Skaill on Mainland Orkney and it is the best preserved Neolithic village in the whole of Northern Europe. With the exception of the Neolithic farmstead at Knap of Howar on Papa Westray (Ritchie 1983), buildings at other Orcadian Neolithic settlements have survived only as stone footings, for example, Barnhouse on Mainland Orkney (Richards 1992 and forthcoming), Links of Noltland on Westray (Clarke, forthcoming), Pool (Hunter and McSween 1991), Tofts Ness and Stove Bay on Sanday (Bond 1995). Rinyo on Rousay was excavated in the late 1930s and it is now reburied beneath the turf (Childe 1938,1946-8). The village at Skara Brae, therefore, is the best example to analyse. Hut 8 is usually interpreted as a workshop (figure 7). It has a central hearth surrounded by flat stones and there are also the footings for a structure in the north-facing wall that was interpreted by Mr. Paterson at the time of excavation as a kiln and a flue (Childe and Paterson 1929:176). Such installations would be ideal for drying the malt and also for baking malted barley cakes/bread. In the porch stood two large Grooved Ware buckets, useful for storing the grain and its products, and inside the hut there were more, together with several large circular stone pot lids, heat-cracked stones and chert or flint scrapers (ibid:174). Hut 8 had all the necessary equipment and installations for grain storage, malting, parching and mashing but there is some interesting evidence for other activities as Merryn Dineley and Graham Dineley well. The fragments of chert around the hearth seem to indicate the manufacture and/or mending of stone tools and a pile of clay perhaps indicates that the building may have been used for manufacture of pots. Hut 8 could probably be more accurately described as a Grain Barn and Workshop. Although Hut 8 has no stone ‘dresser’, many of the other buildings at Skara Brae are furnished with them. They would provide the necessary height for activities such as siphoning the liquid from one vessel to another, perhaps using local reeds as syphon tubes. Hut 7 has both a ‘dresser’ and a stone-built plinth. Also within the Hut, Childe found the remains of a large, very ornately decorated Grooved Ware bucket with a stone lid, which had been standing beside the fire when it was smashed by a roof support during the terrible storm which appears to have blown the roof off (Childe and Paterson 1929:259). Did this vessel contain a fermenting wort or an ale? Gordon Childe describes the floor of Hut 7 as “a slimy mass having very much the consistency of blancmange. It consisted of saturated sand merging into the red clay of the floor” (ibid:250). Hut 7 is the only building in Skara Brae that is described by Childe as being “chaotic and disgusting, a morass of filth” (ibid:259). Such a mess on the floor could have been the result of the sudden spillage of a large quantity of sticky fermenting wort as the large pot by the fire was smashed. Alternatively, the state of the floor could result from many years of brewing activity within the Hut. The extremely sticky nature of brewing and the necessity for access to a water supply and washing facilities for equipment and people was mentioned earlier (Table 1). There are several stone-lined drains at Skara Brae (see figure 6) and Gordon Childe noted a “green slime” in the drainage system, which in places reached a depth of up to 20 inches (Childe 1930:43,41). He interpreted this material as being the remains of excrement. It is interesting that there are no drains attached to Hut 7 and yet this “curious green substance” was found in the circular stone-lined sump at the base of the “dresser” and also in “Pen D”, to the northeast side of the hut. Both of these deposits in Hut 7 had seeped through the clay floor into the underlying sand (Childe 1929:259). If Childe’s interpretation of the green slimy material as decayed sewage is correct, then what was happening at the dresser of Hut 7 to allow a thick deposit of the substance to leach through the clay floor into the sand? A more plausible explanation, surely, is that the green slime may represent the decayed sugar residues from spilt wort or ale. Unfortunately, it has never been analysed and recent excavations at Neolithic Orcadian settlements have not yet come across it. Other Neolithic Orcadian settlements have stone-lined drains, for example, Rinyo on Rousay where similar green deposits were noted (Childe and Grant 1946-8:24) and also Barnhouse (Richards 1992, forthcoming). As any brewer will verify, drains are an essential installation when brewing. With the inclement weather of the Orkney Islands, the ability to dispose of waste liquids via the drains leading to the outside would have been most helpful indeed. The stone buildings of Skara Brae and the surviving internal furniture and drainage systems provide very good evidence for the manufacture of sweet malt products and ale from the grain during the Neolithic. In the newly constructed (1998) Visitor’s Centre, ‘beer’ is listed as being one of the beverages that was probably made and consumed there, but there is a suggestion that it was not a ‘proper beer’ (Clarke and McGuire 1989:22). It would not have been a fizzy beer, flavoured and preserved with hops as we drink today, Neolithic Ale: Barley as a source of sugars for fermentation but a flat ale flavoured and preserved perhaps with meadowsweet, a plant which grows prolifically on Orkney. It would probably have tasted very like the Meadowsweet Ale that we made in our experiments. DISCUSSION AND CONCLUSIONS Our research began as an investigation into the techniques of Bronze Age maltsters and brewers of the British Isles but the focus soon turned to the Mesolithic/Neolithic transition of the Fourth Millennium BC and the reasons for the cultivation and processing of barley grain. The emphasis of our research has been on the practicalities and rituals involved in the conversion of barley grain into sweet malts and ale, a magical and mysterious activity until Pasteur and Tyndall’s experiments into Fermentation in the mid 19th Century revealed the scientific explanation for the process. The biochemistry of brewing is complex but the techniques and necessary equipment are relatively simple. Brewing is, nevertheless, a skilled craft which requires knowledge and experience to make a successful product. The processing of grain into sweet malts and ale is dependent upon biochemical reactions that are unchanged across the millennia. It is an important activity on a mundane level, providing nutritious B-vitamins for the population, but it also has the potential for ritual activity, social hierarchies, status and the possession of secret or specialised knowledge. Women were closely involved with malting and brewing in the Middle Ages (Bennett 1989) and they were probably the maltsters and brewers in prehistory too (Davidson 1999). This is an aspect of cereal processing that we hope to investigate in the future. In the early Fourth Millennium BC a completely new food resource, namely cereal grains, was introduced to the British Isles and it had to be prepared in several new ways. The assumption has always been that the potential products of the grain were flour, bread, porridge or gruel. Our experiments show that sweet malts, malt extract and ale should also be considered as important and significant products. Minimal equipment is required, as shown in Table 1 and as demonstrated in our experiments. Having malted the grain, any further heating with plenty of water will, because of the enzyme action, always produce a sweet product, namely barley mash, barley cakes or malt extract. These products are rich in B vitamins and would have made an attractive, tasty and nutritious new food for early Neolithic people. The spent grain could have been fed to the animals - there is very little waste produced during this kind of cereal processing. Before embarking upon this experimental research, we had not realised the significance of sweet malts - the main ingredient for ale but also a tasty, nutritious and desirable product in itself. Cereal grains are a special food resource that are easily processed into a sweet product. Prior to the discovery of the necessary techniques involved in making a sweet barley mash and malt sugars, the only other source of sugars would have been wild fruits or honey collected from bees nests. Although malting, mashing and fermentation leave minimal traces in the archaeological record, they were clearly among the many activities of British Neolithic people. In our opinion, the British Neolithic had all necessary ingredients, equipment, installations and buildings for processing the barley grain that they grew into sweet malt products and then Merryn Dineley and Graham Dineley into ale. The best evidence for such activity comes from Skara Brae, Orkney, where the buildings and internal furnishings have been preserved amazingly well. Analysis of the green residues in the drains would be most helpful and it is to be hoped that future excavations on Orkney will locate some within drainage systems. The Neolithic settlement at Slara Brae is exceptional and it greatly assists in the interpretation of other Neolithic settlements and buildings of the British Isles that have survived only as wall footings or as post holes. At sites like Lismore Fields, Buxton, Derbyshire (Garton 1987), Balbridie Hall, Kincardine, Scotland (Fairweather and Ralston 1993) and the ceremonial complex at Balfarg, Fife (Barclay et al 1993) the finds of carbonised grain and sludgy, cereal-based residues on Grooved Ware sherds are also strong indications of the manufacture and consumption of sweet malt products and ale in the British Neolithic. Postscript This research is in its early stages and further investigation into the methods and techniques of Neolithic brewers is ongoing. We hope to continue our experiments by fermenting a wort in a replica Grooved Ware vessel, coil built and clamp fired by Andrew Appleby from Harray, Orkney. We must thank Harry Flett of the Corrigal Farm Museum, Harray, Orkney for sending us a bag of malted Bere Barley and we will use it in future mashing and fermenting experiments. We are currently looking into the material culture of the earliest Neolithic of the Levant and the Near East and also into the social and ritual aspects of Neolithic cereal processing in the Near East, Europe and the British Isles. REFERENCES Albarella, U. and Sarjeantson, D. 1997, “A passion for pork: meat consumption at the British late Neolithic site of Durrington Walls” paper presented to the Conference Consuming Passions and Patterns of Consumption” McDonald Institute for Archaeological Research, Cambridge University, September 20th Barclay, G.J. et al 1983 “Sites of the 3rd Millennium BC to the 1st Millennium AD at North Mains, Strathallan, Perthshire” P.S.A.S. 113,122-282 Barclay, G.J. & Russell-White, C.J. eds 1993 “Excavations in the ceremonial complex of the 4th to 2nd Millennium BC at Balfarg/Balbirnie.” P.S.A.S. 123, 42-210. Bennett, J. 1996 Ale Beer and Brewsters in England: women’s work in a changing world Oxford University Press Bewley, R. 1994 English Heritage Book of Prehistoric Settlements Batsford Burgess,C. & Shennan, S. 1976 “The Beaker Phenomenon: some suggestions” in Burgess C. & Miket R. eds Settlement and Economy in the 3rd and 2nd Millennium BC BAR 33, 309-327 Childe, V.G. & Paterson, J.W. 1929 “Provisional Report on excavations at Skara Brae and on finds from the 1927 and 1928 campaigns” P.S.A.S. Vol LXIII, 225-279 Childe, V.G. 1930 “Final Report on the operations at Skara Brae” P.S.A.S. Vol LXV, 2777 Childe. V.G. 1931 Skara Brae: a Pictish Village in Orkney Routledge, London Childe, V.G. and Grant, W.G 1938 “A stone age settlement at the Braes of Rinyo, Rousay, Orkney (First Report)” P.S.A.S. LXIII, 6-39 Childe, V.G. and Grant, W.G. 1946-8 “A stone age settlement at the Braes of Rinyo, Rousay, Orkney (Second Report)” P.S.A.S. LXXXI, 16-42 Clarke, D. L. 1976. The 1972/3 Excavations at Skara Brae, Orkney, an interim report. HMSO Publications Neolithic Ale: Barley as a source of sugars for fermentation Clarke D.V. and McGuire P. 1989 Skara Brae: Northern Europe’s best preserved prehistoric village Historic Scotland Comey, M. 1996 The Archaeology of Ale in early Christian Ireland unpub u/g thesis, University College London, Institute of Archaeology. Conant, J.B. (ed) 1952 Pasteur’s Study of Fermentation. Harvard Case Histories in Experimental Science, Harvard University Press Corran, H.S. 1975 A History of Brewing David and Charles, London Darvill, T. & Thomas, J. (eds) 1996 Neolithic Houses in Northwest Europe and Beyond. Oxbow Monograph 57. Davidson, H.E. 1999 Roles of the Northern Goddess Routledge Dickson, J.H. 1978. “Bronze Age Mead.” Antiquity 52, 108-112. Fairweather, A.D. & Ralston, I. 1993. “The Neolithic timber hall at Balbridie, Grampian region, Scotland:A preliminary note on dating & plant macrofossils.” Antiquity 67 313-323. Flett, H. 1998 Conversations with Harry Flett of the Corrigal Farm Museum, Harray, Orkney on practical matters related to malting, mashing and fermentation Garton, D. 1987 “Buxton.” Current Archaeology 9.8 No103, 250-253. Haggerty, A. 1991. “Machrie Moor:recent investigations at 2 stone circles.” PSAS 121, 51-94. Hodder, I . 1997 “Always momentary, fluid and flexible: towards a reflexive excavation methodology” Antiquity 71, 691-700 Jones A. , forthcoming publication of residue analysis from Barnhouse. Katz, S. & Voigt, M. 1986 “Bread and Beer: The Early Use of Cereals in the Human Diet.” Expedition Vol 28/2, 23-34. Katz, S. & Maytag, F. 1991. “Brewing an Ancient Beer.” Archaeology Vol 44, No 4, 2233. Line, D. 1980. The Big Book of Brewing. The Amateur Winemaker Publications Ltd, Andover, Hants. Long, D., Milburn, P., Bunting, J. M., Tipping, R., Holden,T.G., 1999 “Black Henbane (Hyoscyamus niger L.) in the Scottish Neolithic: a re-evaluation of palynological findings from Grooved Ware pottery at Balfarg Riding School and Henge, Fife” Journal of Archaeological Science, 26, 45-52 Michel, R.H. & McGovern, P.E. 1992. “Chemical evidence for ancient beer.” correspondence in Nature Vol 360, 24. Pasteur, L. 1879 (translated by Faulkener, F, and Robb,C.) Studies on Fermentation. The diseases of beer: their causes and the means of preventing them. McMillan & Co Piggott, S. 1931 “The Neolithic Pottery of the British Isles” Archaeology Journal Vol LXXXVII, 67ff Richards, C. 1992. “Barnhouse and Maeshowe” Current Archaeology 131 Ritchie, A. 1983. “Excavation of a Neolithic farmstead at Knap of Howar, Papa Westray, Orkney.” P.S.A.S. 113, 40-121. Ritchie, A. 1995. Prehistoric Orkney B.T. Batsford/Historic Scotland Robinson, M. .............the Yarnton barley cakes........................................................... Samuel, D. 1995 “Rediscovering Ancient Egyptian Beer.” Brewer’s Guardian, December Samuel, D. 1996. “The Archaeology of Ancient Egyptian Beer.” Journal of the American Society of Chemists, 54 (1), 3-12 Merryn Dineley and Graham Dineley Sherratt, A. 1995 “Alcohol and its alternatives: symbol and substance in pre-industrial cultures” in Goodman, J. et al Consuming Habits: Drugs in History and Anthropology Sherratt, A. 1996 “Flying up with the souls of the dead” British Archaeology, June Simpson, D. 1996 “Balleygalley Houses, Co. Antrim, Ireland.” In Darvill, T. & Thomas, J. (eds), Neolithic Houses in Northwest Europe and beyond. Oxbow Monograph 57. Tyndall, J. 1876 Extract from his speech on Fermentation to the Glasgow Science Lectures Association, in Conant, J.B., 1952 Pasteur’s Study of Fermentation, Harvard University Press, USA Vencl, S. 1994. “The Archaeology of Thirst.” Journal of European Archaeology, 2.2, 229-326 Wainwright, G. J. and Longworth, D.1971. Durrington Walls Excavations, 1966-68 London Society of Antiquaries Wickham-Jones, C.J. 1990. Rhum: Mesolithic and later sites at Kinloch. Society of Antiquaries of Scotland Monograph Series, No 7, Edinburgh