I'm not sure what's more surprising about "bog butter" — that it's theoretically still edible, or that the stuff is a "common find" in Scotland and Ireland.
Either way, it's fascinating. That a 22-pound lump of butter was buried 12 feet deep in Ireland's Emlagh bog for over 2,000 years is incredibly weird. But its original placement there might have been fairly mundane. Bogs make for great long-term storage, which ancient people knew. With a little oxygen and cool temps, bogs naturally preserved things, basically acting like a natural refrigerator. Food placed in them could act as nutritional insurance for lean times. Other research has shown that bog butter may have been an offering to local gods, since butter is a rich food with lots of calories.
Turf cutter Jack Conway found the giant store when he was out digging peat to burn for heat, and he gave it to the National Museum of Ireland, where it will be kept in a refrigerated case.
Experts estimate Conway's creamy cache is about 2,000 years old, though specific radiocarbon dating is needed. Previous bog butters have been much older. As Smithsonian details, "In 2009, a 77-pound, 3,000-year-old oak barrel of the stuff was found in County Kildare. In 2013, a turf cutter in County Offaly found a 100-pound, 5,000-year-old chunk. Many examples of the butter are found in Irish museums, including the place dedicated to the golden spread, Cork’s Butter Museum."
From 1817 to 1997, when Caroline Earwood wrote a paper for the Journal of Irish Archaeology on the subject of bog butters, 279 butters were unearthed. Earwood writes, “It is usually found as a whitish, solid mass of fatty material with a distinctive, pungent and slightly offensive smell. It is found either as a lump, or in containers which are most often made of wood but include baskets and skins."
The butter is thick and waxy after all that time aging; it has a crumbly texture and some say it smells like a strong cheese. But it's definitely still butter. Savina Donohoe, curator of the Cavan County Museum, told UTV Ireland, "After I had held it in my hands, my hands really did smell of butter."
This video shows a bog butter found in 2011 in Tullamore, Ireland:
The Emlaugh butter is considered a significant find as it's located at "the juncture of three separate kingdoms, and politically it was like a no-man’s-land — that is where it all hangs together,” Andy Halpin, the assistant keeper in the museum’s Irish Antiquities Division, told The Irish Times.
While most people won't be spreading this archeological find on toast anytime soon, celeb chef Kevin Thornton says he tried some that was 4,000 years old: “I was really excited about it. There’s fermentation but it’s not fermentation because it’s gone way beyond that. Then you get this taste coming down or right up through your nose,” he told the Independent. And he's planning on serving some — not the 4,000-year-old kind, but a new batch, that will age in a bog for about 6 months.
“If I was to have a food trend, my food trend would be bog butter," said Thornton.