Page "Draught beer" Paragraph 2

Until Joseph Bramah patented the beer engine in 1785, beer was served directly from the barrel and carried to the customer.

The Old English word for carry was dragen which developed into a series of related words, including drag, draw, and draught.

By extension, the word for carrying or drawing a beer came to mean the serving of the beer and, in some senses, the act of drinking, or a drink of beer itself, regardless of serving method.

By the time Bramah's beer pumps became popular, the use of the word draught to mean the act of serving beer was well established and transferred easily to beer served via the hand pumps.