Irish corn-drying kilns, their Bronze Age origins?

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.

cereal drying kiln
Corn drying kiln (by Alan Braby for National Museum of Scotland)

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.

bronze age corn dryingkiln
Knockgraffon corn-drying kiln

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.

Carrigtogher corn drying kiln (copyright: Headland Archaeology)

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.

Reconstructed corn-drying  kiln
Reconstructed corn-drying kiln

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


12 thoughts on “Irish corn-drying kilns, their Bronze Age origins?

  1. This article seems too accepting of the quoted authors interpretations – there are multiple potential hypotheses for some of those feature groups, not just the corn-drying kiln.
    Interconnecting pits may have been ‘clothed’ with timber structures similar to troughs in burnt mounds.

    And the presence of charred grain in a pit does not indicate grain became charred there -only that it was deposited there.

    1. Hi John, thanks for your thoughts! You can never keep an archaeologist happy :). As I didn’t work on most of the sites mentioned I had to rely on the directors interpretations. Admittedly the information on the ‘kilns’ from the excavation bulletins can be skimpy, but the two main kiln sites mentioned in the blog post seem pretty convincing (well to me anyway). I wonder would we even be asking this question if they had returned early medieval dates? Sometimes, if it excavates like a kiln, looks like a kiln, and acts like a kiln, maybe it’s just a kiln?

  2. Admin should delete that last show of ignorance.

    Archaeological excavation is based on multiple working hypotheses – each hypothesis must be tested rigorously by the evidence available and a final preferred hypothesis arrived at by a process of elimination.

    There are other possible hypotheses for those feature groups besides a CDK and if you can’t think of them cos they ‘quack like a duck’ then I’d ask that you engage in the academic exercise of trying to come up with some alternatives. What other processes would involve interconnected pits? Salt, soap, fat, food…Ask what this structure could have looked like when it functioned in antiquity? Sketch the alternatives.

    At least offer a word of caution or an alternative hypotheses.

    ‘The current preferred hypothesis is that these are early CDKs but an alternative hypothesis is that they are poorly preserved remnants of some other domestic/agricultural process/structure.’

    I am not teaching anybody ‘to suck eggs’ here but as you are taking the blog-with-comments approach to publication then I am offering my opinion as a comment. The article would be stronger if it were more critical in its approach.

    There should also be some consideration of the provenance of the C14 dates.

  3. John, thanks for the response. My original post was based on the opinions of the actual excavators who dug these sites, and frankly I agreed with them. You don’t, which is fair enough, and hence this discussion is taking place (a good thing). If you would like to post a counter argument I’d be more than willing to put it up on the website (even though you are already kind of doing it in these comments). My blog posts are intended to be short introductions on the latest happenings in Irish archaeology for both the lay person and professional archaeologists. Finding the balance between academia and accessibility is my goal. Colm

  4. Colm, the site and approach is fresh and very well executed and is the way of the future but accessibility must also include critical thinking – one of the values of archaeology is that it encourages critical thinking.

    I do not suggest you change your fresh writing style but if you are going to the trouble of listing extensive comparanda then why not add alternative hypotheses as well.
    If I read anything (final reports, monograph chapters) we produce, or anybody elses for that matter, I always look for their alternatives.

    What comes to mind is the Waterford City excavations in the late eighties. When a number of houses were being written up after the first phase of excavations they were interpreted over a few pages as single-aisled structures with lanes between but the alternative was offered, as a single paragraph, that they may also be three aisled structures. The director allowed for a number of possibilities although preferring one. Subsequent excavations and better preservation conditions allowed for a reinterpretation by the same excavators as the houses being v definitely three-aisled.

    I can also think of an internal project where the field crew dug the site as a kiln but when the dates came back it was reinterpreted as a fulacht fiadh. The director, an excellent Irish field archaeologist had just never seen such a degraded fulacht fiadh before. So I hope I am not being holier-than-thou; I just think good science requires all field archaeologists to think in multiple hypotheses and good science writing to reflect that.

    As for writing a response I have something coming out later this summer on interconnected pits (based on which I will link back to here.

    Rgds John
    PS. Of course I should have also allowed that Robert might be a Polish digger with a very high opinion of himself instead of presuming ignorant bigotry. Some of the best field archaeologists, and nicest people, I have worked with over the last 5 years have been non-Irish.

  5. Thanks for your input John and I’ll definitely take your comments on board. I look forward to reading your article. All the best, Colm.

  6. @ John Tierney: You mention in the discussion that you would link a publication of yours from Summer 2011 regarding interpretation of interconnected pits, i would really appreciate this as I am writing an undergraduate dissertation covering, in part, misinterpretation of CDK features and I cannot find the publication you mention (and very few others relating to this topic). Thank you.
    Conor McAdams

    1. Hi Diane. Corn tends to be used as catch all phrase when describing a variety of cereals in Ireland and the UK. When we say corn we mean all of the cereal types and not one specific grain species. It comes from the Old English word ‘korn/corn’, which basically means grain. All the best,

  7. Being Irish American,with no knowledge of Ireland’s Ancient History, I am thrilled to read article’s like this. It opens my mind,helping me to understand my Ancestors, and their abilities. Thank you.

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