Longmont’s Left Hand Brewing is suing its yeast supplier after the brewery said contaminated yeast led to a $2 million recall of its Milk Stout Nitro and IPAs last year.

The lawsuit was filed in Boulder District Court by Indian Peaks Brewing — which does business as Left Hand Brewing — on Nov. 14 against White Labs Inc. and was first reported by Courthouse News.

The lawsuit alleges that “contaminated yeast product supplied by White Labs caused secondary fermentation in beers brewed using that yeast, including Milk Stout Nitro, resulting in over-pressurized bottles, broken bottles, off flavors, and disruption of the distinctive nitrogen cascade.”

The lawsuit said the contaminated yeast required Left Hand to issue recalls for the stout, Extrovert IPA and Warrior Fresh Hop IPA and destroy thousands of barrels of unpackaged beer.

Left Hand — which operates out of 1265 Boston Ave. in Longmont — also had to shut down its brewery for two weeks and disassemble its equipment, according to the lawsuit.

The company said that an investigation discovered that the beer was contaminated by a strain of wild yeast called Saccharomyces cerevisiae variant diastaticus that is known to cause secondary fermentation in beer.

According to the lawsuit, Left Hand was able to trace the source of the wild yeast to White Labs. Left Hand said it used White Labs yeast exclusively to brew several beers, including the Milk Stout Nitro and the two IPAs involved in the recall.

“It is unfortunate we had to file a lawsuit, but we didn’t have a choice,” Eric Wallace, co-founder and CEO of Left Hand Brewing, said in a statement.

Milk Stout Nitro is the company’s flagship beer, with the beer making up about half of the company’s sales historically, according to the lawsuit.

To read more of this story go to dailycamera.com