In NE145, a review of the ‘Celts’ exhibition that took place in London and Edinburgh observed the curiosity of a wooden keg assumed to have held drink being made from the highly toxic yew. Mark Greener considered the implications.
At first sight, yew isn’t the wood you’d choose for a tankard, bucket or barrel. Yew’s toxicity is legendary. Pliny the Elder warned that just eating under a yew could prove to be your last meal. We now know that only 50-100g of yew leaves can kill an 80kg person.1 Indeed, the term toxic seems to derive from the Greek for yew – Taxus. Yet stave-built yew buckets, tankards and barrels are found across Late Iron Age Britain and Continental Europe, in Anglo-Saxon graves2 and in the recent Celts exhibition (NE 145, p27). So what lies behind this seeming paradox?
A group of related chemicals called taxines are responsible for yew’s toxicity. Only the scarlet berry (aril) isn’t, apparently, toxic1 (I wouldn’t put it to the test). All other parts, whether fresh or dried, contain taxines, which poison the heart. Taxines are present throughout the year, but peak during the winter.1,3 Interestingly, several writers link the yew – associated in druidic lore with death, renewal, self-transformation and rebirth – to Samhuinn or the winter solstice.4
Our ancestors probably appreciated that yew was most toxic in winter, which helped cement the symbolism. A similar process seems to underlie the astrological concordances and folk stories associated with certain plants. These traditional frameworks allowed healers to recognise patterns, organise knowledge and apply collective wisdom to particular problems.5
So harvesting yew greenwood in the summer, when the taxine levels were lowest, would reduce the risk. Dry yew remains toxic for several months.6 But leaving wooden barrels and tankards to season probably reduced the levels.
Nevertheless, people died after drinking wine stored in yew flasks.2 Indeed, a study in the Journal of Chromatography found that immersing yew heartwood in red wine for 30 minutes extracted taxines and the broader groups of chemicals to which they belong, called taxoids. The alcohol seemed responsible. Pure alcohol extracted four times more toxoids than red wine. Immersing the heartwood for 30 minutes in hot black or white coffee extracted far less, but levels were still detectable. The researchers also detected toxoids in soft cheese spread onto the wood and then scraped off with a knife: so it’s probably not a good idea to cut cheese on a yew board.3
Jonathan Horn in the Proceedings of the Prehistoric Society points out the findings suggest “that the consumption of alcoholic beverages from yew vessels could be potentially dangerous, though probably required prolonged exposure”. Beer is lower in alcohol than wine and probably ‘extracted’ less taxines.2 Beer was also probably drunk rapidly rather than stored in the yew vessels. But I still wouldn’t swig from yew tankard. As Horn remarks, several “other variables such as the levels of taxoids required and contact duration for a lethal dose are still unclear”.2
Yew is, however, durable and resists decay when wet. Indeed, indigenous communities across North America and Asian prize yew for house construction, furniture and utensils. Closer to home, yew has been used since the stone age for making bows, axe shafts and spears.7 In 1911, for example, Samuel Hazzledine Warren found a fragment of yew on the foreshore at Clacton that was probably the point of a stone age thrusting spear.8 The spearhead’s survival since Neolithic times shows yew’s durability.
Nevertheless, Horn comments that yew is “an extremely uncommon choice” to make vessels. Ash or oak are durable and were used to make stave-built vessels and tools. Yew is also prone to splitting and is difficult to work. So yew’s toxicity is probably intertwined with the vessel’s “symbolic role”. As Horn notes, choosing to use to yew was “unusual and deliberate”.2
Symbolic and ritual objects made of yew include Bronze Age votives and early medieval reliquaries.2 But ephemeral events can be as symbolic as physical objects. Michael Dietler, for example, notes that “food and drink have an especially prominent place in ritual and religion”. Importantly, food and drink are material objects made to be destroyed by ingestion into the body. As such, food and drink have “a heightened symbolic and affective [emotional] resonance in the social construction of the self”.9
Feasts offer a “highly condensed” symbol of social relations and status.9 Having been bought nouvelle cuisine in London restaurants, the fact that I would much rather eat fish and chips in Hunstanton, Cromer or Whitley Bay says more about me than their relative culinary merits. In other words, feasting is inherently political. Alcohol’s psychoactive and ‘transformative’ effects can result in a particularly symbolic ritual role.9
Perhaps the aura of toxicity meant that the yew barrel and tankards symbolise a social relationship – evoking macho comradery in a beer-swilling warrior class, for example. Perhaps the yew’s durability allowed the barrel’s use over several years, such as during the midwinter feasts. I am, of course, indulging in a little armchair speculation. Nevertheless, yew tankards and barrels show how layers of meaning from the practical and prosaic to the exotic and esoteric can surround even an ‘everyday’ object such as a barrel or a tankard. And such objects embody a profound knowledge and deep understanding of nature that we’ve largely lost.
References
- C R Wilson, J-M Sauer, S B Hooser. 2001. ‘Taxines: a review of the mechanism and toxicity of yew (Taxus spp.) alkaloids’. Toxicon 39:175-185.
- J A Horn. 2015. ‘Tankards of the British Iron Age’. Proc Prehistoric Soc. 81:311-341.
- G C Kite, E R Rowe, N C Veitch et al. 2013. ‘Generic detection of basic taxoids in wood of European Yew (Taxus baccata) by liquid chromatography–ion trap mass spectrometry’. Journal of Chromatography B 915-916:21-27.
- P Carr-Gomm 1991 The Elements of the Druid Tradition: Element Books.
- R Bivins. 2007 Alternative Medicine? A history. Oxford University Press.
- R Cope. 2005. ‘The dangers of yew ingestion’. Veterinary Medicine 100:646-650.
- R C Poudel, L-M Gao, M Möller et al. 2013. ‘Yews (Taxus) along the Hindu Kush-Himalayan region: Exploring the ethnopharmacological relevance among communities of Mongol and Caucasian origins’. Journal of Ethnopharmacology 147:190-203.
- K P Oakley, P Andrews, L H Keeley et al. 1977. ‘A Reappraisal of the Clacton Spearpoint’. Proc Prehistoric Soc 43:13-30.
- M Dietler. 2011. Feasting and Fasting. In: I Timothy (ed.). The Oxford Handbook of the Archaeology of Ritual and Religion. Oxford University Press.
Published in NE146 pp11-12
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