A number of recent archaeological excavations have shed light on the possible ancient origins of corn-drying kilns in Ireland. These structures played an important role in cereal production, especially in damp climates such as Ireland where they were used to remove moisture prior to storage as well as to harden cereals to facilitate threshing and milling. They were used right up until the 19th century and would have been a significant part of the local agrarian economy. The kilns typically consist of a sunken pit, which may be keyhole or figure-of-eight shaped in plan. This was then covered in a superstructure that could be made out of variety of materials such as earthen sods, wood, stone and straw. In nearly all archaeological excavations, all that survive of the kilns is the sunken pit that would have held the fire source and over which the grain was dried.
Until recently it was assumed that corn-drying kilns were an agricultural innovation that was introduced to Ireland from Late Roman Britain where a number of similar kiln types are known. This belief was reinforced by the fact that the vast majority of excavated Irish kilns date from the Late Iron Age (0-400 AD) or, especially, the Early Medieval period (400-1200 AD). However, a number of recent excavations have demonstrated that in Ireland corn drying kilns may have had a much earlier, Bronze Age ancestry.
For example at Knockgraffon, Co. Tipperary a Middle Bronze Age figure-of-eight shaped kiln was recently excavated by Colm Moriarty to the south of a Late Bronze Age roundhouse (McQuade, Molloy & Moriarty, 2009, 33). The kiln, which measured 3.8m in length, consisted of two concave bowls (pits), separated by a short flue. The larger western bowl had evidence for in situ burning along its sides and base, suggesting that it acted as a fire chamber, while the smaller eastern bowl was probably where the grain was dried. A large quantity of indeterminate cereal grains were recovered from the kiln, in addition to three barley grains (ids Ryan Allen), while charcoal analysis indicated that four different types of wood were used as fuel namely ash, hazel, oak and pomacious fruitwood (possibly hawthorn; ids Lorna O’Donnell). A single cereal grain from near the base of the kiln was radiocarbon dated to 1667-1496 BC (2 sigma) making this one of the oldest, if not the oldest, corn-drying kiln yet excavated in Ireland.
Another, slightly younger, Middle Bronze Age kiln was also excavated near Nenagh in Co. Tipperary. It was uncovered at Carrigtogher (Harding) townland by Liam Hackett, along works associated with the new N7 motorway (Hackett 2010, 34-35). The kiln was very similar in size and form to the Knockgraffon example, and it was radiocarbon dated to c. 1520-1435 BC. It was also figure-of-eight in plan and consisted of a drying chamber, a fire chamber and a short connecting flue. Samples taken from the fills of the kiln showed that charred wheat grains, indeterminate cereals and hazelnut shell were present.
These two Middle Bronze Age kilns are an important addition the Irish archaeological record as they indicate that a sophisticated means of processing crops may have been available in Ireland at much earlier date than previously thought. They don’t appear to be the only examples either, as a number of other probable Bronze Age kilns have also been excavated, including a keyhole-shaped kiln from Kilsharvan, Co. Meath, a wedge shaped kiln from Clonmoney North, Co. Clare, a sub-rectangular kiln form Laughanstown, Co. Dublin, a kiln from Ballybarney, Co. Wicklow and a possible kiln pit from Doonmoon, Co. Limerick (Russell 2003; Murphy 2003; McQuade 2005; Gregory 2004; Gowen 1988, 53). While slightly further afield, a Middle Bronze Age (1446–1367 BC) keyhole-shaped kiln has recently been excavated at Kames in Argyll, Scotland (Ellis 2013, 3-4).
Together these structures suggest that corn-drying kilns may have been an indigenous innovation, which pre-dated Roman farming practises by a considerable length of time.
(post edited 15-1-2014)
Ellis, C. 2013, ‘A Bronze Age corn-drying kiln from Argyll’ in the The Past, The Newsletter of the Prehistoric Society, No. 75, October, pp. 3-4
Gowen, M (ed.) 1988 Three Irish Gas Pipelines: new archaeological evidence in Munster, Wordwell, Dublin.
Gregory, R 2004 ‘Ballybarney, Co. Wicklow’, in I Bennett (ed.), Excavations 2002, 528. Wordwell, Bray
Hackett, L 2010 ‘the earliest cereal-drying kiln in Ireland?’ in M Stanley et al (eds.) Seanda, NRA Archaeology Magazine, Issue 5. NRA, Dublin
McQuade, M 2005 Final Report on Excavations at Cherrywood Science and Technology Park II District Centre Lands, Co. Dublin. Unpublished report for Margaret Gowen & Co. Ltd.
McQuade, M, Molloy, B & Moriarty C, 2009 In the Shadow of the Galtees; Archaeological excavations along the N8 Cashel to Mitchelstown Road Scheme, The National Roads Authority
Murphy, D 2003 ‘Clonmoney North, Co. Clare’, in I. Bennett (ed.) Excavations 2001, 12. Wordwell, Bray
Russell, I 2003 ‘Kilsharvan 1, Kilsharvan, Co. Meath’, in I Bennett (ed.), Excavations 2001, 302. Wordwell, Bray