Bog Butter - Unearthing Irish History

In the run up to Halloween, we’ve thought we’d share a spooky story from one of our more recent visits to Ireland: bog butter.

As you probably know, we love good Irish butter here at Flaherty’s - it’s the secret to our delicious, tender toffees! On a recent trip to Ireland (pre-Covid-19, of course) we visited the Butter Museum and heard a tale that certainly piqued our interest. 

Ireland, like many places in the British Isles, is home to peat bogs, a particular kind of swamp. The peat, formed by generations of plants, is sought after as a fuel, and as an excellent addition to potting soil. However, while digging for peat, people often come across ancient casks containing something unexpected: butter!

These casks of “bog butter” are often old - some date back to the first century AD. Buried deep in the peat, they’ve been preserved for hundreds and hundreds of years. In County Offaly in 2011, a cask was unearthed that contained over 100 pounds of bog butter! 

Why on earth would anyone bury their butter in a swamp? Scientists can only speculate. Beneath the surface, peat bogs are cool and have very little oxygen, making them a great place to preserve cold foods. Perhaps the ancient Irish used peat as an early fridge! Researcher Daniel C. Fisher at the University of Michigan found that storing meat and dairy in peat bogs can keep it fresh enough to eat for up to two years (though we don’t recommend trying it!)

Image courtesy of Navaro, CC BY-SA 3.0

However, some believe that the butter was buried not to keep it fresh, but to change its flavor. In places like Yemen, butter is still intentionally aged and fermented into smen, which is a bit like the butter equivalent of bleu cheese. Perhaps the ancient Irish found that bog-aged butter tasted better! At the Oxford Symposium on Food and Cookery in 2012, attendees tried a three-month-old bog butter created by the Nordic Food Lab to a mixed response. Some enjoyed it, others described the flavor as “gamey” and “pungent.”

Would we ever use bog butter in a toffee? Of course not. But for lovers of fresh Irish butter, this seemed like the perfect spooky tale to tell on Halloween! Would you try a little modern bog butter? Or will you stick to Kerrygold?