Pennsylvania residents can buy wine from vending machines but first they must pass a breath test to prove they haven't been drinking.
The state, which already controls sales of wines and spirits through a network of 620 state-run retail stores, is testing out two wine kiosks at supermarkets in Harrisburg and in nearby Mechanicsburg.
If it is successful another 98 will be rolled out across the state this autumn.
After selecting a bottle of wine from the 55 on display customers must insert a driver's licence showing they are over 21, the minimum age to legally buy alcohol in the United States.
Their identify is verified via video link by a member of the Pennsylvania Liquor Control Board (PLCB) who can see the customer in front of a camera installed in the kiosk.
Next customers must blow into a breathalyzer to make sure their breath-alcohol level is not more than 0.02, or just one quarter the legal limit for driving. If it is, the sale will be denied.
Stacy Kriedeman, a spokeswoman for the PLCB, said the breathalyzer is designed to perform the same service as liquor store employees who deny service to anyone who appears to be drunk.
"They are both doing the same thing but in a different way," she explained, adding that the test has been going well since it started on June 23.
Less than 50 of the 2,600 customers who have used the machines and purchased about $35,000 (22,000 pounds) worth of wine have failed the breath test, according to PLCB chairman PJ Stapleton.
Revenue is 30-40 percent higher than expected.
State government has controlled the retail and wholesale drinks trade in Pennsylvania since the end of prohibition in 1933, giving it, along with Utah, the strictest alcohol regime among U.S. states, Stapleton said.
Sixteen other states sell alcohol through a combination of public and private sectors.