Alaskan Brewing's grain-burning furnace is the first in the world

Tons of dried grain used to make Alaska beer that would once have been shipped to the Lower 48 is now being reused in-state -- to brew more beer.

In October, the Alaskan Brewing Company began using a new $1.8 million boiler specially designed to burn the "spent" grain produced in their Juneau beer-making operation. A statement from the U.S. Dept. of Agriculture, which supplied a renewable energy grant of $488,366 to the project, said it was the only brewery in the world using spent grain as its sole fuel source.

Curtis Holmes, ABC's plant manager, said the company expects to cut its fuel oil consumption by up to 70 percent and save $1.5 million in fuel costs over the next 10 years.

Half of the energy from the furnace creates steam to boil malted grain, the main ingredient in beer after water. The other half dries out the used "spent" grain, some of which is used for fuel. The rest of the spent grain is shipped to Seattle.

Before the boiler came on line all of the spent grain had to be sent to the lower 48, where it was used as livestock feed. Shipping waterlogged grain was expensive, so in 1995 the company installed a device to dry it out and reduce the weight. Some of the dried grain was able to be burned to dry out more grain, but it was not as efficient as it might have been.

"It's not a good fuel," said Holmes, "full of proteins, tough to burn."

In 2008 the company switched to a mash filter press, which adds efficiency but costs more than traditional methods. It was the first craft brewery in America to use this method, which Holmes said is more prevalent in places like Africa where water is scarce.


"But without the mash filter press we never would have been able to do the biomass boiler," he said.

Holmes, in Anchorage for the Great Alaska Beer and Barley Wine Festival at the Egan Center, said the press created spent grain that was easier to dry, not as wet and finely ground, more like a powder than traditional cracked grain.

Personnel from the brewery visited plants in a variety of industries that burn sawdust, corn husks and other waste plant products to determine how to make a practical firebox for the grain, which tends to blacken on the outside without burning completely. The Juneau machine shakes the grain to expose unburned surfaces to the flames.

Right now some of the grain dried by the boiler is still sent to farms in the lower 48, but Holmes said the company's goal is to "burn it all" and use the excess energy to run help run the brewhouse.

After burning, about 5 percent of the grain's weight remains in the form of ash. "Unfortunately, that's all going to the landfill at the moment," Holmes said. The company is looking for ways to use it in making fertilizer or concrete products.

But the grain burning itself is a win-win, he said. "It's a tricky fuel to use, but it's all biodegradable. There's nothing else in it, no glue or paint or anything. We're reusing a waste product that already been used."

Reach Mike Dunham at or 257-4332.


Mike Dunham

Mike Dunham was a longtime ADN reporter, mainly writing about culture, arts and Alaska history. He worked in radio for 20 years before switching to print. He retired from the ADN in 2017.