Butter That Stays Good for 3,000 Years

Reader Contribution by Brian Kaller
1 / 5
2 / 5
3 / 5
4 / 5
5 / 5

When most people picture Ireland, they picture our characteristic green fields and old stone walls. But Ireland also has lots of bog – the Bog of Allen, where I live, stretches almost a thousand square kilometres across several counties. Bogs are difficult to get through or settle in even today, so they were isolated, mysterious places, where characters in folktales met banshees or other supernatural beings, and a good place for starving and subjugated people to hide, or hide things.

A bog is a natural wetland, like a swamp or marsh – the difference is that the water is very acidic and low in oxygen, so that insects, fungi and even most bacteria can’t survive. Things buried in the bog don’t rot, so it made a clever place to hide things if you could find them again. Farmers here still find trees that fell in centuries ago, the wood stained black but not rotten. Sometimes they find possessions hidden in the bog that their owners never came back for; necklaces, coins, tools, swords. And sometimes they find stores of food, up to 3,000 years old and not only intact, but edible. Specifically, they find butter. 

Bizarre as that sounds, more than 430 caches of butter have been found in bogs, some small as fists, some big as barrels. The aforementioned 3,000-year-old butter weighed more than 35 kilos, the size of a child. And a surprising number of adventurous finders sampled the butter, and reported it delicious.

This doesn’t even count all the buried gastronomic treasure still waiting out there. Since we can suppose that people buried their butter to unearth and eat it later, and usually did so, these hundreds of finds must represent the small proportion of times that their owners died or the locations forgotten. This must have been a rather commonplace activity.

So why butter, you ask? A surprising number of foods around the world are preserved by being buried in the ground, but they are usually dried foods in arid climates (cheese in Italy), or sub-Arctic countries where the ground is freezing (salmon in Sweden), or where the food is meant to ferment in some way (eggs in China). In this case it’s waterlogged ground, it would probably disintegrate in the water over time unless it’s naturally waterproof, like fat. 

This might have been done with meat as well; Archaeologist Daniel Fisher buried various meats in a frozen pond and a peat bog for comparison, and found that after a year, the meat buried in the bog had no more bacteria than the frozen meat. If this sounds gross, keep in mind that fast-food burger you last ate might have been more than a year old as well.  

Also, butter makes a valuable and high-calorie food for poor agrarian people; with it you can fry food or preserve things like potted meats. It was also taxed in medieval times, so burying it could have been a kind of tax evasion.

The constantly-cold Irish bog would keep the butter solid, and it would only age like cheese; in fact, the one taste-tested by Irish schoolchildren was said to taste like well-aged cheese. Some people might simply have liked the taste.

Like most people these days, we have a refrigerator to keep food fresh, and it runs on electricity – and here in Ireland, we strip-mine our bogs to get turf, burn the turf in a furnace to produce heat, use the heat to spin magnets, and use the magnets to generate electricity to run the refrigerators to keep food fresh. Sure, we do a lot of other things with that electricity, but it’s an admittedly complicated process to keep your butter fresh – burying it in the bog creates no carbon footprint and generates no waste, and skips all the steps in between.

I like to experiment with old ways of preserving food; I learned how to preserve fruit over winter, how to preserve eggs in lime-water or isinglass, how to pickle vegetables or learn which mushrooms are edible. But in all those things I had people around to show me; lots of my older neighbours still make their own jam or wine. I don’t know of anyone who’s ever tried this who could show me how. Thankfully, it’s pretty straightforward – all you need is to access to one of the world’s peat bogs, and I happen to live in the middle of one.

I made some butter at home, which anyone can do; you just pour milk and cream into a jar, put on some music and start shaking. I couldn’t fill it more than a quarter full or we would just get whipped cream, so I had to do this many times to get the three pounds. At some point the sound of the sloshing changes, and you get a solid clump of butter in the middle of the liquid. Traditionally Irish housewives would pat the butter dry of its remaining liquids, but we simply clarified it. Then I froze it to keep it solid while I handled it, wrapped it in cheesecloth and a rope, and walked about ten minutes from our house into the bog.

I paced the steps first in one direction and then another to make sure I would remember the spot, and tied the rope to a nearby tree to I could find it again. 

Seventeen months later I dug up the butter, and while the picture looks pretty disgusting, once I washed it off and unwrapped it the butter looked much the same – a darker yellow and with an earthy smell, but not rancid. 

The taste was recognizably butter, but with an umami flavour a bit like parmesan or ripe cheese; I don’t know how baked goods would taste using it, but it was particularly good over popcorn. It wasn’t something most modern people would choose to eat regularly, but for people who faced periodic famines, it was an ideal store for lean times. 

Of course, this butter was only in the bog for 17 months, and the effects are probably very different over 3,000 years. So I’m burying more butter for a longer period of time – dozens of kilos — and planning to unearth it in about three to five years, some further down the road. When I do, I’ll dig it up and report on the results, and if you want to come visit, you can be one of the few people in the world who can say they had this ancient food. 

I’m pleased to say this experiment was featured on the BBC Program QI, which looks at interesting facts from around the world: for more information search the internet for “QI” and “Quagmire” or look up my web site at Old School School.


Brian Kaller is a newspaper columnist and homesteader in County Kildare, Ireland. He gardens, keeps bees, interviews elderly neighbors about traditional ways of life, learns old-time crafts, and writes about it. His work has appeared in The American Conservative, Front Porch Republic, First Things, Resilience.org, GRIT and has been featured on the BBC program QI. Find Brian’s writings at Old School Schooland videos on Old School School on YouTube. Read all of his MOTHER EARTH NEWS posts here.

Lucy Vaserfirer’s Flavored Butters provides the recipes and techniques for homemade flavored butters. In 50 recipes, she offers up ideas that are amazingly quick to execute in the kitchen and transformative in the flavor they impart. The recipes cover both sweet and savory applications, and each includes advice about what the butter is best used on. Plenty of photographs illustrate the recipes, and you’ll also find ample tips and tricks: Learn the perfect temperature at which to serve the butters, how to serve them, and the tools needed for making stunning presentations. Order from the MOTHER EARTH NEWS Store or by calling 800-234-3368.


All MOTHER EARTH NEWS community bloggers have agreed to follow our Blogging Guidelines, and they are responsible for the accuracy of their posts. To learn more about the author of this post, click on their byline link at the top of the page.

Need Help? Call 1-800-234-3368