Over the last century, though, industrial farming and large-scale spirits production have encouraged distillers to focus on a limited range of grain varieties, grown not for taste but for alcohol yield, with much of the flavor coming later, in the barrel-aging process.

“This whole idea of terroir has been bred out of us by the large grain producers because it’s inimical to mass production,” said Mark Reynier, who built the Bruichladdich Distillery in Scotland around terroir-specific whiskeys before selling it to Remy Cointreau in 2012. (He is now at work on another terroir-driven project, the Waterford Distillery in Ireland.)

For example, almost all the corn used to make bourbon is a high-yield, relatively flavorless variety called Yellow Dent No. 2 grade, grown by the millions of bushels across the Midwest.

“When I was learning to distill, all I was taught was ‘buy Yellow Dent, Number Two Grade,’” said Rob Arnold, the head distiller at the Firestone & Robertson Distilling Co. in Fort Worth, who is also pursuing a doctorate in plant breeding and genetics at Texas A&M.

For his dissertation, Mr. Arnold is examining how soil and climate in different parts of the state affect the flavor characteristics in corn, and whether those qualities come through in a distilled and aged spirit — a project that, he believes, will help him make whiskeys that can be identified with specific parts of Texas. “What I’m hoping to do is tap into flavors that have been forgotten,” he said.

A similar effort is underway at High Wire, where Mr. Blackwell and his wife, Ann Marshall, produce estate-specific rums and whiskeys, drawing on crops grown along the South Carolina coast, and inland along the Pee Dee River.

Working with farmers across the state, they make their bourbon using a variety of corn called Jimmy Red, which they selected with the help of Glenn Roberts of Anson Mills, a South Carolina company that sells heirloom grains.