Scientists test beer by-product from Diamondback Brewing Co. to prevent algae blooms like one in Pasadena lake


A new strategy to prevent toxic blue-green algal blooms is brewing at a Maryland lab where scientists are experimenting with spent grain, used and discarded as part of the beer-making process.


In years past, researchers at the University of Maryland Center for Environmental Science have used barley to prevent harmful algal blooms in the freshwater Lake Williston on the Eastern Shore.

Researcher Allen Place said they put barley straw in the lake’s tributaries. Over a period of months the barley rots, and as water trickles down to replenish the lake, it moves through the rotting bales, which release compounds that prevent blue-green algae from forming.

Taylor Armstrong, a doctoral student in Allen’s lab, has found a source that can add those same compounds to the tributary without waiting months for barley to rot. Beer, or more specifically the spent grain left over after the fermentation process in brewing.

“It’s full of compounds that inhibit algae,” Armstrong said.

There are saltwater algal blooms, like red tides. But recently the freshwater-dwelling cyanobacteria, also known as blue-green algae, have been in the news after three dogs died after swimming in a North Carolina lake. In Anne Arundel County, the health department issued an advisory in July saying the toxic algae has been found in Lake Waterford in Pasadena.

Anne Arundel County’s Acting Director of Environmental Health Don Kurtian said the algae was still present when they last tested Aug. 6. He said this year is the first time the algae has appeared in Lake Waterford, and it was possibly accelerated by a hot spell in July.

Although, the strategy the scientists are testing wouldn’t help Lake Waterford because it’s preventative and the bloom has already begun.

The spent grain can be put in the water and immediately release those algae-inhibiting compounds, and Allen and Armstrong are hoping they could even make an extract from the spent grain to add to bodies of water.


Their findings are still preliminary, Allen said. They haven’t tried putting down spent grain in a tributary yet, but experiments in a laboratory have been promising. Armstrong is at the start of her career as a doctoral student, and wants to write her dissertation on natural ways to kill and prevent algae.

“She has shown that there is material in spent grain, in the lab, that inhibits the growth of this toxic algae,” Allen said.

The grain she used in the lab was used to make pilsner at Diamondback Brewing Company in Baltimore, Armstrong said.

Spent grain is an easily accessible resource that could use a second home — 85% of the by-product left over from beer production is spent grain, Armstrong said.

While these fixes can prevent blue-green algae, safeguarding curious dogs and drinking water sources, they’re just fighting symptoms, not the disease, Allen and Armstrong said.

They need to stop the flow of nutrients into the water, from sources like sewer overflows, agriculture and lawn fertilizer, UMCES researcher Pat Glibert said. Toxic algal blooms are happening more often and in more parts of the globe. It’s not just how many inches it is raining in a year, she said, but how intense the storms are.


There is more nutrient runoff during heavy rain storms than a gentle rain, she said, and the frequency of such events is expected to increase.

“Unless we begin to put ourselves on a nutrient diet as a planet, we are going to see more of these events more often,” Glibert said.

Glibert is developing computer models that will predict when and where harmful algae blooms occur, how climate change will affect them in the future and how nutrient reduction strategies could help.

She said it is very important for the public to heed warnings posted at contaminated lakes.

Allen said it’s a good rule for you and your dog to stay out of green water. Armstrong said if you see a bloom you should report it, which you can do online on the Department of Natural Resource’s Eyes on the Bay website. Officials can test the bloom to determine if it is toxic or not, she said.