You just never really know when you are going to find something unexpected. I’ve known for a long time that early medieval Ireland had a heavily cattle based economy, really a dairy based economy. Most of this product would be used for local consumption, as a primary source of both calories and protein. During my research for Kalamazoo this past spring, there were many things I learned that were along the lines of what I expected.
The Irish recognized several forms of milk and milk products. Law codes and other sources mention whole milk, skim milk, buttermilk, cream, curds and whey, and nine different kinds of cheese (graded based on their chewiness!). Butter was a special food for the elite and eaten both fresh and salted. Out of these products, I would have expected cheese to be a primary foodstuff and a trading product. Afterall, cheese is the most durable dairy product. Yet, I really couldn’t find evidence for trade in Irish cheese.
Butter! Butter is the only dairy trading product mentioned. Why butter? Well, real butter doesn’t need refrigeration so it could be transported. Kerr, McCormick and O’Sullivan found a letter between Waldebert and Bobolenus found within the prologue of Jonas’ Life of Columbanus, written in the 640s, that life at Bobbio in northern Italy was so austere that the monks barely have enough Irish butter (‘ex Hibernia…butyrum’) to get by compared to the luxury Mediterranean goods at other monasteries. They view this as indicating that Irish butter was cheap and plentiful as far away as Italy. They note that in the 19th century, Irish butter was traded across the Atlantic without refrigeration so that it would have been possible. Ok, so we have Irish butter kings… (sounds odd) but never the less, still why butter rather than cheese? Perhaps since cheese is more durable, making butter was something only done where there really is a lot of excess milk, not often done in most areas with fewer cattle. Kerr, McCormick and O’Sullivan calculate that an average productive medieval cow could produce about one pound of butter per day easily producing enough for trade and local consumption. That being said, Irish cattle management was not very advanced; many of their cattle would not have been productive. Cattle in Ireland at the time didn’t calf until age 4 and a calf had to be kept with them to keep them milking. There is little evidence of butchering calves or yearlings.
So for all the novelists out there, feel free to spread the butter around. Only put it on bread for elites though, because the poor didn’t have much bread at all. They ate mostly gruel or porridge made from barley or oats (essentially oatmeal). I imagine they cooked with a lot of milk, cream or butter for added nutrition and flavored with salt and honey. They could also add some meat (mostly pork) and vegetables including peas or beans. I imagine ham and beans could have been on the menu occasionally.
(Another cattle based trade product was leather. Not just as raw leather hides but shoes are specifically mentioned in trade accounts. Irish ships arrived on the continent with clothing and shoes for trade.)
McCormick, F. (2008). The decline of the cow: agricultural and settlement change in early medieval Ireland. Peritia, 20(-1), 209–224.
Kerr, T., McCormick, F., & O’Sullivan, A. (2013). The Economy of Early Medieval Ireland. (pp. 1–103). Irish National Strategic Archaeological Research (INSTAR) program 2013. (open access)
McCormick, F., Kerr, T. R., McClatchie, M., & O’Sullivan, A. (2011). The Archaeology of Livestock and Cereal Production in Early Medieval Ireland, AD 400-1100 (pp. 1–813). Early Medieval Archaeology Project (EMAP2). (open access)