The puncheon was a British unit for beer, wines and spirits.
[1] It was also an American unit of capacity for wine.
[2] Historically, the puncheon has been defined somewhere between 70 and 120 imperial gallons (318 and 546 litres; 84.1 and 144 US gallons).
[1] The US puncheon for wine is defined as 84 US gallons (318 litres).
[2]