Ethanol plants use hops to eliminate bacteria
LUCAN, Minn. -- Ethanol companies are looking back to the monasteries of ancient Europe for one possible solution to a troublesome production issue.
They have to control bacteria to make good ethanol. The most common weapon, antibiotics, works well enough, but it's becoming a public relations headache.
Earlier this year, the Food and Drug Administration said it was finding antibiotic residue in an ethanol byproduct. That byproduct is sold as feed for cattle and other livestock, which is a problem. For the ethanol industry, the findings raised the threat of both bad publicity and government regulation.
That prompted the ethanol industry to hunt for other ways to control the bacteria that hurt ethanol production. Kerry Nixon manages an ethanol plant in central Minnesota and he said industry insiders he talks with believe many plants have already started using one of two main alternatives to antibiotics.
"They figure about 30 percent of the plants are either trying it now or are already on it," Nixon said.
One of the most promising options dates back more than a thousand years and is still very much in use today.
Hops have long been a staple ingredient for the beer industry. Beer maker Dustin Brau and his brothers have planted more than a thousand hops vines near their brewery in the small southern Minnesota town of Lucan.
Brau said hops -- which look like small, green pine cones -- do add flavor to beer, but he said it also has another benefit.
"The unique characteristic of hops is, it has anti-
bacterial qualities," Brau said.
Brau said by reducing bacteria, hops is helpful in any sort of alcohol fermentation. Hops block bacteria that consume sugars in the mash. Left alone, the bacteria would turn the sugars into acid instead of what's really desired, alcohol. Legend has it that the monks of Europe's Middle Ages were the first to notice the value of hops.
And now, the ethanol industry is giving it a try.
"We've been extremely busy," said William Popa, national sales manager for a company that sells hops to the ethanol industry. "Since the first of the year we've had a lot of interest in our product."
Popa works for the BetaTec company. Popa spends most weeks traveling interstate highways to different ethanol plants interested in trying hops.
"Most of the ethanol plants that we talk to are being very pro-active and curious," he said. "The industry as a whole is changing, and anything that can help with production or efficiency they'll give it a shot."
One of Popa's customers is Rob Carson, who runs an ethanol plant in Kansas. Carson switched the plant from antibiotics to hops several years ago; in part because of concern the standard industry practice could fuel the growth of antibiotic resistant bacteria. He said the more recent finding of antibiotics in a feed for beef cattle and other livestock is also troubling.
"Because you're actually putting that back into the food chain," Carson said.
The concerns about antibiotics are prompting academic research into alternatives. Minnesota ethanol plant manager Kerry Nixon said at this point, most facilities making the switch are choosing hops.
Nixon said the company he works for, Central Minnesota Ethanol Co-op in Little Falls, considered using hops but eventually opted for something else; it's using chlorine to kill bacteria.
"It seems like it knocks it out right away," he said. "And there's no residual effect at all, so it's worked very well for us."