Technology, and changes in how people live and shop, made the dairy business innovate again and again during the 100 years that Colteryahn Dairy operated out of Carrick.

The population of the United States grew by leaps and bounds in the late 1800s. The western frontier disappeared, although more Americans still lived in rural areas – on farms – than in cities. Milk was transported from dairy farms by train. It was distributed locally by William Colteryahn and many others on horse-drawn wagons. “Housewives would come to the wagon with their kettles and pans to purchase the milk,” according to the Carrick-Overbrook Historical Society.

In 1917, the United States declared war on Germany and entered World War One. Ford Motor Company assembly lines were putting a Model T into many driveways. And Carl Colteryahn opened a dairy at 1601 Brownsville Road in Carrick Borough.

Soon, fresh milk was delivered to city homes daily using milk trucks instead of horse-drawn wagons. Then people bought refrigerators for their homes. They didn’t need daily milk delivery.

Rock-n-roll transformed pop music in the late 1950s. The Cold War clash between communism – personified by the Soviet Union – and capitalism, led by the United States, dominated news headlines. Still, about one in three Americans had milk delivered. More than a dozen dairies – including Colteryahn Dairy – operated milk routes in the South Hills. Here’s how it worked. A milkman drove his truck through a residential area with several hundred homes. He stopped at his customers’ houses to deliver bottles of fresh milk. He set the bottles in a milk box, retrieved empty bottles and collected his payment. He got to know his customers as a way of selling more products. He was always on the lookout for new customers.

During the 1950s and 60s, World War Two veterans and their wives raised large families. Many of their children moved into the suburbs – away from the traditional milk routes. In the suburbs, houses were usually more spread out, and housewives took to shopping at grocery stores. The economics of the situation made milk routes less profitable. Dozens of neighborhood dairies disappeared from Pittsburgh.

Colteryahn Dairy added grocery stores as customers. It wasn’t enough.

In 1962, the Beatles released their first single, Love Me Do, on vinyl. First Lady Jackie Kennedy set fashion trends with her perfectly tailored suit dresses. Astronaut John Glenn orbited the earth, proving that whatever the Soviet Union could do, Americans could do better. And the Colteryahn family opened the first Stop-N-Go convenience store in the area to expand the market for the dairy’s milk. The Colteryahn’s chain grew until about 70 company-owned and franchise stores existed in western Pennsylvania. The name was changed to CoGo’s in the mid 1980s. About a third of Colteryahn Dairy’s revenue came from selling milk, juice and tea through CoGo’s stores. CoGo’s was sold to Coen Markets, which operates convenience stores throughout the tri-state area.

By the early 1990s, the Soviet Union was entirely gone. The U.S. led a coalition of 35 nations into war against Iraq. Riots devastated Los Angeles after the verdict in the Rodney King trial. And production at the Colteryahn Dairy was completely modernized. Colteryahn Dairy’s equipment was updated again in the late 1990s, and again in the 2010s.

Along the way, Colteryahn Dairy became the oldest dairy in Pittsburgh, and then the only dairy in the city.

The dairy no longer relied on selling milk under the Colteryahn label at grocery stores. They developed niche businesses to succeed in a changing marketplace. In an approach called co-packing, they packaged and labeled milk, juice, iced tea and sour cream just how the chains wanted. They sold small cartons of milk to schools. They hustled soft-serve ice cream mixes to amusement park. They provided milk and other products to universities, nursing homes and jails.

I have a lot of the business that the big dairies don’t want

Carl Colteryahn III in an interview with the Pittsburgh Tribune-Review available at the Carrick-Overbrook Historical Society

The dairy started a line of Burgh Teas. An iced tea/lemonade drink was promoted with Allegheny County. Pictures of Allegheny County parks were featured on the bottles, which contained coupons for discount admissions at county pools, golf courses, ice rinks, ski slopes and snow tubing. Other Burgh Teas labels promoted Kennywood, and the Pittsburgh Zoo & PPG Aquarium.

Colteryahn was a driving force behind the idea of constructing the Carrick Dairy District, a dairy-themed business district on Brownsville Road to revitalize the community and improve the quality of life for the residents.

In the mid 2010s, subdued colors became fashionable, same-sex marriage was legalized, people commonly used smartphones and Colteryahn Dairy added online ordering. People could shop for Colteryahn products online and pick up their orders at CoGo’s.

As Colteryahn Dairy’s 100th anniversary loomed, it was sold to Turner’s Dairy of Penn Hills. The dairy continued to operate under the name Pittsburgh Special-T Dairy. It produced co-packed products as before and added Turner branded products. Pittsburgh Special-T is located at 1601 Brownsville Road, Pittsburgh, PA 15210, in the same spot where Colteryahn Dairy existed for a century.