Chefs cook with compost heap’s heat

Easter dinner is all about the ham. Some say it's because devout Christians wouldn't eat meat for all of Lent, some say it's based on some old pagan god. But no matter what, we're guessing you're going to see a big old spiral-cut gracing the table this Sunday.

But Easter is also a celebration of renewal and rebirth, of nature's born-again bounty, of life springing through winter's cold, brown clutches. What could be a more appropriate culinary symbol for the circle of life than a compost pile turned oven?

One big New York restaurant--yet to be named, since it's still working out the legality of the whole thing--is using the heat from decomposing scraps to cook food. In the peak of their life cycles, compost heaps can reach internal temperatures of 160-170 degrees, which is hotter than most sous vide circulation baths. In other words, cooking with compost (when done right) is totally safe. And you know what tastes great when slow-cooked at a constant temperature? Ham.

Suzanne Podhaizer, the chef at the Montpelier, VT restaurant Salt, actually cooked a whole meal just using compost heat last November, when the air temperature around the heap in question dropped below freezing.

"I have friends who work at compost companies, and I knew they would bury things in the compost and eat it later," Podhaizer said, "but those were mostly leftovers from the night before. This was the first time I'd thought of using compost to cook from scratch."

Podhaizer cooked the meal at the Highfields Center for Composting in part to promote a Kickstarter the center had going (they're looking to fund a new system for capturing the compost's heat), but also out of professional curiosity. She laid out a menu of branzino, scallops, radicchio, garlic, minced red peppers, and jasmine rice, wrapped it all up in plastic bags and aluminum foil, and popped it in the pile for about four hours.

"The fish turned out very nicely, and I just tossed the radicchio with some dressing after taking it out, and it came out very well," she said. "The rice was cooked, but it kind of lost all of its texture--it got compressed by the weight of the pile on top of it."

The biggest limitation Podhaizer saw to the method was the lack of precision, when cooking a whole meal at once. "Every time we dig into the pile, we lose the heat, so we weren't able to take things out at different times." she said. "There wasn't that nuanced ability to cook things just right."

Podhaizer only experimented with cooking fish in the compost, and thought that cooking a raw roast might not be the best idea. "You want the inside of meat to get to about 125 degrees for rare," she said, "so the question is how long it's in the danger zone. But we just weren't sure, because we don't have enough data."

But thanks to the brave efforts of a man named Jim McClarin, we do know something about cooking meat in compost. Back in 1980, McClarin documented his compost cooking experiments for Mother Earth News, conducted in the compost heap in his backyard.

McClarin's first compost cooking experiment was with making yogurt (remember: Mother Earth News), which needs a certain warmth to get the bacteria bubbling right. He knew his compost was warm, but to his surprise, it got so hot that it skipped the yogurt stage and turned straight into cheese!

From there, he tried cooking an egg (in a plastic bag), and ended up with "the most mouthwatering hard-boiled egg of my life." But then, most importantly, he tried cooking a raw roast in his heap.

And it worked! He popped the roast in his big yogurt tub, and put it in a part of the pile that read 155 degrees on his meat thermometer. He left it in there overnight (for thirteen hours), and pulled out a delicious hunk of meat. Next, he actually took a whole duck "with orange juice and apricots," popped that in the compost pile, and let it sit for 23 hours. When he took it out, he writes that it "was perfect when I served it with wine and wild plum sauce."

A man after our own hearts. McClarin ended his article, as we must end ours, with a caveat: "My limited knowledge of microbiology doesn't permit me to recommend compost cookery to anyone else. I can merely state that it works just fine for me!"

But chef Podhaizer's experience shows that, if nothing else, a compost heap can do a number on fish and veggies, and if you're working with a pre-cooked ham, as many people do on Easter Sunday, it can surely warm up the meat. Like a certain savior's tomb, just make sure that your cooking container is sealed tight (Podhaizer used five layers of alumninum foil, wrapped in different directions) so it's the compost heat and not the heap that gets into your food.