Donna Wessel

For the year before the brewer Mark VanGlad arrived at Friday’s Union Square Greenmarket lugging cases of his new beer, he was a busy man.

Last spring, Mr. VanGlad, 25, who owns Tundra Brewery, planted his own barley and hops, which he harvested in the fall. As the company’s only deliveryman, Mr. VanGlad drove the barley from his family’s farm in Stamford, N.Y., to Massachusetts to be malted. He developed the recipe for his maple-infused pale ale, and brewed it in a facility that he rigged up from old steel dairy tanks. And in Albany, Mr. VanGlad was the one who navigated the bureaucracy to get Tundra’s microbrewery licenses.

On Friday, as Tundra’s promoter and sales clerk, Mr. VanGlad staffed the brewery’s new stand at the Greenmarket and handed out samples of his pale ale to an eager crowd of beer quaffers.

“I really feel like I accomplished something,” Mr. VanGlad said. “Here I am, a year later, and I just sold 30 cases.”

Tundra is the first brewery to sell beer at the Greenmarkets, but Mr. VanGlad is a familiar face in Union Square. His father and uncle run Wood Homestead, a 25-year-old maple syrup stand, and he has helped out at market since he was a small boy.

In 2009, the state passed legislation that allows New York brewers who make fewer than 60,000 barrels a year to sell at farmers’ markets, as well as at county and state fairs. Wineries were already allowed to sell at markets under the Farm Winery Act of 1976.

Tony Cenicola/The New York Times

“It seemed like I lucked out,” Mr. VanGlad said. “I was in the right place at the right time.”

Mr. VanGlad flavors the pale ale with his family’s syrup and has labeled it Ma-Pale.

After an informal sampling at his desk, Eric Asimov, the wine, beer and spirits critic for The New York Times, described Ma-Pale as “cloudy and amber, with a fresh, almost breadlike aroma, gentle carbonation and dry, savory, hoppy flavors.”

So far, Mr. VanGlad has made three 155-gallon batches, each of which produces 70 cases. Six-packs of the beer, which has an alcohol content of 4 to 5 percent, sell for $13, or two for $25, at Union Square Greenmarket on Fridays and at the Tucker Square Greenmarket on the Upper West Side on Saturdays.

Mr. VanGlad’s work dovetails with the Greenmarket’s efforts to promote local grain production, said June Russell, the manager of farm inspections, strategic development and regulations.

“We have been trying to engage beer makers in our grains work for the last couple of years,” she said.

The 2009 state law allowing brewers to sell at markets does not specify that the beer must be made from local barley and hops, but Greenmarket rules on beverages require that all the beer’s ingredients be locally grown and that 60 percent must be grown by the seller.

As far as she knows, Ms. Russell said, Mr. VanGlad’s is the only entirely farmer-produced beer in the state. Although the avid market for craft beer has nurtured the growth of boutique brewing operations in New York, most of the barley and hops used to make that beer is imported from Europe or elsewhere in the United States.

The hops in Tundra’s ale are among the first to be grown in New York — which once produced most of the nation’s supply — since the crop was damaged by disease and pests early in the 20th century, and then wiped out by Prohibition.

The lack of small malt houses to process barley for beer production has added to the challenge of brewing beer from local grain. This stymied Mr. VanGlad at first, he said, until he heard about a small malt house, Valley Malt, in Hadley, Mass., that was willing to malt his barley.

Marketgoers weren’t the only ones who took notice of Mr. VanGlad’s Ma-Pale ale on Friday. By the end of the day, Tundra had an offer from a restaurant keen to make a wholesale order. Jeffrey Zurofsky, a partner in the ’Wichcraft sandwich stands, Riverpark restaurant and the Southwest Porch lounge at Bryant Park, hopes to be the first restaurateur to sell Tundra beer, he said.

“It’s great beer,” Mr. Zurofsky said. “Oftentimes you have local products where the idea is really good, but the execution lacks. That’s not the case here. This is something that we’d be proud to sell.”

Last week’s successful debut felt like a vindication of all his hard work, Mr. VanGlad said. But even after running the stand from 8 a.m. until 6 p.m., he didn’t have the luxury of kicking back with a cold beer on Friday night.

“I had to get up early to do another market,” he explained. “So I’m saving the celebration.”