Researchers at Chicago’s Omega Yeast Labs recently identified a gene in certain yeast strains that are more likely to produce haze in beer, according to a press release. While brewing experts typically consider hop oils and proteins to be the biggest factors in the signature cloudiness of some IPAs, the research team’s findings suggest that yeast’s genetic makeup plays a larger part in producing hazy beers.

The R&D team at Omega Yeast Labs, which sells specialized yeast to craft breweries and homebrewers, first discovered the link during a routine experiment. While using a yeast strain to mimic the traits of IPA fermentations, they discerned that certain strains of yeast produced more haze than others. They then linked these “haze-positive” strains to a shared gene they’ve dubbed HZY1, which they now believe is a noteworthy factor in beer’s haziness.

To further test the theory, researchers removed the gene from these haze-producing yeast strains, and then used those strains to ferment beer. They found that beers created with those modified yeast strains didn’t produce the cloudiness they typically would.

“Brewing yeast [has] been so extensively studied, we never thought we would be the first to identify a new gene for haze,” Omega Yeast Labs research director Laura Burns says. “Now that we have a gene, there’s no denying that yeast play[s] an important role in promoting haze in beer.”

The lab says that it anticipates brewers using this new study to inform yeast preferences for IPAs and to create new recipes.