Ancient Irish Butter Has Been Found Perfectly Preserved for 5,000 Years

Every year in Ireland, people cutting peat moss for heating discover mysterious yellowish lumps buried deep in the bogs. This is 'bog butter'—dairy products placed underground millennia ago. The finds can be remarkably ancient. In 2013, a turf cutter found a 100-pound chunk estimated to be 5,000 years old. In 2009, a 77-pound barrel of 3,000-year-old butter was discovered. Even a relatively modest 22-pound lump found in 2016 was believed to be 2,000 years old. The butter was made from cow's milk and buried in the cool, damp, low-oxygen, high-acid environment of peat bogs—a perfect natural refrigerator. Early Celtic people likely stored butter this way to preserve it or protect it from thieves. Butter was a valuable commodity used to pay taxes, so saving it for times of drought, famine, or war made sense. Some researchers think burying butter might have been a form of food processing that changed its flavor. After thousands of years in the bog, the butter takes on the consistency of paraffin wax and a pungent, cheesy odor. A curator who handled a recent find said her hands smelled of butter afterward.