When you think of beer brewing in Burlington, zebra mussels might not quickly come to mind. But maybe they should... Photo: Wikimedia ...

A closer look: How does our lake change our beer?

When you think of beer brewing in Burlington, zebra mussels might not quickly come to mind. But maybe they should...

Photo: Wikimedia Commons

In 2006, Greg Noonan, late founder of the Vermont Pub and Brewery in Burlington, explained this phenomenon in a piece called Brewing Water: Tips from the Pros for Brew Your Own Magazine.

He wrote:

"(W)hen we began brewing at Vermont Pub and Brewery 18 years ago, our water was very soft. However, in the intervening time our own ‘great lake’ Champlain has been invaded by zebra mussels. When the little suckers die, their shells disintegrate into calcium carbonate. Our water supply has become much more carbonate, and therefor (sic) more alkaline. As Jim Koch of Sam Adams pointed out to me years ago, alkalinity produces dull-flavored beers."

Of course, water is a main ingredient in beer. Local water sources have shaped the variety of brews created across the globe and understanding the chemistry involved makes it possible to recreate certain styles.

Noonan was saying, in essence, when substances are added to water, aside from the existing two-hydrogen and one-oxygen molecules, the molecular make-up and pH level change. 

“Soft water” refers to the minerals found inside. The hardness of water is measured by the amount of calcium and magnesium recorded. Soft water has low concentrations of the minerals, and hard water has high concentrations. They can be salts with positively-charged mineral ions bonded negatively-charged ions, like carbonate and sulfate.

When these ions are added to water, the separate and react with others nearby. Water can react with rocks, like limestone (calcium carbonate) or gypsum (calcium sulfate). Lake Champlain doesn’t have many of these minerals in its rocks, but they are found in mussel and snail shells, too. The presence of these negatively-charge carbonate ions can raise the pH and as a result the alkalinity. 

Photo: Wikimedia Commons

Research has suggested that, in most cases, lakes have enough dissolved calcium to support zebra mussel infestation, but the creatures could have altered the amount of the substance actually dissolved. It is possible that calcium carbonate levels rise in the winter, when zebra mussels stop growing or die off and are not taking in the substance from the water. 

Noonan credited changes in the water at Vermont Pub and Brewery to the zebra mussels’ infestation. When older mussels die, they add carbonate and alkalinity to the water he then uses to brew. Data has not completely proven Noonan’s theory, but examining this further does show how the lake’s ecology affects in unexpected ways.

This occurrence is not unique to the Champlain – a Minnesota brewery developed its own ale made from zebra mussel shells and Eurasian milfoil taken straight from the lake.
Excelsior Brewing Co., on Lake Minnetonka, has said this is a way to save the lake from “aquatic hitchhikers.”

To learn more about the science behind local brewing, be sure to check out this month’s Echo AfterDark event, FeBREWary, on Thursday, Feb. 12 at 7 p.m. This month we’ll examine, and taste, a variety of dark beers.

Written by Jessie Forand based on this original blog post from February, 2013.

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