Scientists identify proteins responsible for home brew haze

PERTH, Australia, July 23 (UPI) — Home brewers dread beer haze, often called chill haze because it appears after a freshly brewed beer is chilled for the first time. The haze is not only unattractive, but it can also reduce a beer’s shelf life.

Now, researchers in Australia say they’ve identified two proteins responsible for the phenomenon, allowing them reduce the chance of hazy beer.

The culprit in the tragedy of hazy beer is barley. By breeding barley without the two key proteins, researchers were able to reduce the risk of beer haze by 30 to 40 percent. Currently, barley growers and brewers select haze-free strains by sight. It’s an unscientific approach that doesn’t always work.

Researchers say they are in the early stages of being able to tell barley breeders and growers how to develop haze-free strains of their crop.

“Traditionally brewers treat their beer to remove haze proteins, to keep the beer looking good and extend shelf life, but in that same process they remove flavor and foam proteins as well,” researcher Chengdao Li, a professor at Murdoch University, told Science Network Western Australia.

But home brewers don’t have access to that process, and many — along with microbrewers — aren’t willing to sacrifice flavor.

Li and his colleagues have developed a test that allows barley growers to test new strains to determine whether the genes for haze-producing proteins are present.

“We can use these molecular markers to test all the varieties and say ‘yes, Variety A will easily form haze, but Variety B won’t have that problem,’” Li said.

Of course, many home and microbrewers — even those that take steps to rid their brews of chill haze — are quick to remind would-be beer makers that haze is simply a matter of aesthetics.

“Chill haze will not affect beer taste at all,” Stone Brewery brewer Mitch Steele recently told readers. “The chill haze has no flavor.”

In other words, stop staring and drink.