Peat diggers in Ireland and elsewhere have occasionally unearthed objects, usually made of wood, that contained some kind of greasy, fatty material with a “distinctive, pungent and slightly offensive smell”.
Butter. Centuries-old butter.
Who buried it, and why, remain mysteries that motivated Ben Reade, an experimental chef at the Nordic Food Lab in Copenhagen, to make some himself. He brought some of his modern-day bog butter, still nestled in moss and wrapped in its birch-bark barrel, to share with the Oxford Symposium on Food and Cookery last year.
Notes Ben mentioned two plants that have been found around bog butter, hypnum moss (Hypnum cupressiforme) and bog cotton (Eriophorum angustifolium).
The Nordic Food Lab research blog details all of their astonishing edible experiments.
I found Seamus Heaney reading his poem Bogland at The Internet Poetry Archive.
Caroline Earwood (1997) Bog Butter: A Two Thousand Year History, The Journal of Irish Archaeology, 8: 25-42 is available at JStor, which has a new scheme allowing you to read up to three items at a time online for free.