From Wikipedia, I thought this common knowledge, but apparently not.
Hogshead . The hogshead of beer and ale was equal to a quarter of a tun, half a butt, a barrel and a half, or three kilderkins. This unit is close in size to the wine hogshead . In the mid-15th century the ale hogshead was defined as 48 ale or beer gallons (221.8 L).
Stop the angry PMs.