Mark Pattison picks a hop cone off the vine and rapidly rolls it back and forth between his hands. A sticky, yellow powder coats his palms, releasing an aroma that’s woodsy yet floral.

“See that? That’s what you want,” Pattison says, holding out his hands to show how they’ve turned yellow from the lupulin — the oil inside hops that give beer its bitter flavor and aroma. “These (hops) are perfect.”

Pattison is one of...