Some cutsy faux redneck bars here (States and Canada) serve beer in Mason jars. "Jar" for a beer or a drink came over in the 19th century, largely disappeared, but has come back, I think, because of these places.
A digression from slang, but when I first came to Canada, my favorite pigging concoction was a chocolate malted milk (an ice cream based milkshake with malt added). The use of malt in a milk shake was unknown here at the time, but milkshakes with ice cream were available. A favorite drink here is is the Caesar, which Canadians can't find in the States. It is a Bloody Mary made with Clamato juice rather than plain tomato juice.