The 10 lines at the Dairy Bar around dinnertime usually stretch to the street from the round-barn building, with more than 100 people waiting to get their relatively inexpensive milkshakes and grilled-cheese sandwiches.

But the long lines don’t seem to stop fairgoers from waiting up to half an hour at the beloved institution, which has been serving fresh dairy products at the fair since the 1940s.

The Indiana State Fair vendor is part of the non-profit organization American Dairy Association of Indiana, and it gives all of its profit to the volunteers who work there.

On average in 2014, the Dairy Bar sold 4,000 milkshakes a day and more than 2,000 grilled-cheese sandwiches each day of the fair, according to a press release from the dairy association.

At $3 each, that adds up to $18,000 per day in just milkshakes and grilled cheeses, so the volunteer groups get a chunk of change for their work.

Each day, a different group of volunteers works as cashiers, cooks and runners to churn out massive amounts of milkshakes and sandwiches.

Janet Springfield, from Lapel, has volunteered at the Dairy Bar for the past 16 years with her Sunday school class at Trinity United Methodist.

“We need the money, and it all goes to missions, so it goes to a good place,” Springfield said.

Inside its black and white spotted building—just like its cow namesake—the Dairy Bar may look chaotic, with workers rushing around to get orders filled, but orders arrive at the windows in minutes, even seconds.

“It’s wholesome, all milk and dairy,” Springfield said. “There’s nothing but dairy products, and the prices are reasonable. There are good people to be around and I like it.”

Kimberly Brake was working as a cashier to support her daughter, who is a gymnast at Mid-America Gymnastics, which volunteered Thursday.

“It’s a simple job and everyone is really friendly,” Brake said.

The lines are long each day because the Dairy Bar is such a great establishment, she said.

“For grilled cheese, the price is a pretty good reason why people come,” Brake said. “It’s a good place to take kids.”

Jenni Browning, senior director of communications and wellness at the American Dairy Association of Indiana, said the group’s goal is to break even after paying their volunteers and buying supplies.

“We like to give back to the community,” Browning said. “Our volunteer organizations appreciate the opportunity to raise money for their activities.”

She said of the 34 different organizations that volunteer, many come back year after year. Their longest serving group is Lincoln High School athletics, which has been coming for 27 years.

“We run the Dairy Bar … to draw attention to Indiana’s 1,200 hardworking dairy farm families and the many delicious options dairy offers,” Browning said.

Kara Berg is a writer for BSU Journalism at the Fair, a group of 30 students telling Indiana’s stories from a trailer somewhere between the cheese sculpture and the state’s biggest sow. This Ball State University immersive-learning project works for elephant ears.