When Nicholas Impellitteri gets home, he’s often greeted by a package of beer waiting for him on his doorstep. This continual supply of craft lagers, pilsners, ales and saisons is thanks, in part, to his obsession with yeast.

The self-described “chief yeast wrangler” is the founder and lead scientist behind the Yeast Bay, an East Bay-based business that provides commercially unavailable and rare yeast strains to the home brewing and commercial beer-making community. As one of the most crucial ingredients in determining a beer’s flavor profile, mouthfeel and overall drinkability, Impellitteri explains that just one strain of yeast can produce dozens of different flavors, depending on the brewing process. Even as a yeast expert, he’s continually surprised by the flexibility of the fungus.

“I get to taste 10 beers from 10 different brewers who all used the same culture, but whose beers all came out differently,” he says. “That they can artfully coax different character out of the same yeast is pretty awesome.”

Back in 2011, unexcited by the range of yeast available to home brewers, Impellitteri began experimenting with his own blends of yeast, which he often sourced from lambic-style beers. He noticed a demand for his creations after posting about his experiments on social media and decided to make a business out of his unique hobby.

“While a lot of other companies largely offer the same cultures, what I focus on is isolating and creating new yeast, which is a much more niche market,” he explains. “I don’t have to compete for market share for cultures that are already well-established, and this allows me to add something new to the market, which is pretty exciting.”

Impellitteri begins the process by isolating and characterizing yeast sourced from other beers in his lab, growing those specimens and brewing his own test batches with selected yeasts—all of which he characterizes as a cycle of wash, rinse and repeat. After creating flavor profiles for each brew, the Yeast Bay outsources its creations to a large-scale manufacturer called White Labs for production. Impellitteri says this allows for him to focus mainly on the research and development of new strains, while quality control stays in the hands of an established manufacturing company.

The Yeast Bay currently sells 35 varieties of brewer’s yeast, wild yeast, bacteria and experimental beta cultures to roughly hundreds of commercial breweries and thousands of homebrewers worldwide on a rolling basis, a customer base that’s steadily growing every month. Impellitteri notes that he’s even seen a handful of homebrewers, who began using his products as hobbyists, turn their beers into full-scale production.

“It’s been cool to be part of that growth and a real honor that people come to us to get their organisms,” he explains. “Yeast is one of the biggest deciding factors on how a beer is going to taste, and it can make or break a beer. The fact that they put so much faith in us is flattering.”

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