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Under the Microscope: Opening Up About Open Fermentation

What is open fermentation, and why do some brewing businesses—both traditional and modern—swear by it? Here we take the lid off this method and consider its unique set of strengths and drawbacks.

Don Tse Oct 31, 2022 - 12 min read

Under the Microscope: Opening Up About Open Fermentation Primary Image

Open fermentor of helles at Private Landbrauerei Schönramer in Schönram, Bavaria. Photo: Joe Stange.

When Casey and Dorothy Letellier were planning their brewery, Casey started by making a list of the breweries that had influenced him. The list included breweries from around the world—Belgium, Britain, Germany, and the United States—yet there was a common thread that tied them all together.

So, when the Letelliers opened the doors of Ivory Bill Brewing on September 15, 2018, the fact that it was the only brewery in Siloam Springs—a Northwest Arkansas town of about 17,000 people—wasn’t the only thing that made it unique. Like those of the breweries that inspired it, all four of Ivory Bill’s fermentors are open.

“There is something about them that just makes them really special,” says Casey Letellier of the British-built, stainless-steel, open-top fermentors.

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Don Tse is an internationally recognized beer writer and beer judge, working from his home base in the middle of North America’s barley belt.