BARRELS, KEGS, CASKS, VATS, TANKS...
It is believed that wooden barrels or casks may have been made as long as 2,000 years ago by the Celtics. These wooden containers were adopted by the Gauls and then by the Romans, replacing clay and ceramic containers known as amorphaes, which would break more easily and were somewhat awkward to move. In comparison, the barrels broke less often and their round shape allowed them to be rolled, making them easier to move. They could also be stacked. Such barrels or casks were originally used for food, liquids, gun powder and other purposes. The use of tar allowed these vessels to be waterproof. They were used for wine by the Romans, and possibly beer. The oldest surviving beer barrel used in Europe dates from the 1500s, over 500 years ago. The making of barrels is known as cooperage, and people working in this trade are known as coopers.
COMPONENTS OF OAK BARRELS, KEGS...
There are several different parts to a wood barrel or cask. The main component are wood "staves" which are held in place by galvanized metal strips or bands called "hoops." A diagram showing the components of a barrel is on the side. Not shown on the diagram is that there can also be a hole on the head near the croze of chime for a spigot or valve to drain liquids from the barrel when it rests on its side. The head can also contain a hole off-centered on that allows for liquid to be accessed when the barrel is upright (as shown) with a metal tube that extends to the bottom connected to a handle and spout, and with pressure to draw out the liquid possibly from the assistance of CO2 canister or cartridge. An example of this is shown in a photo below.
Often the above terms barrels, casks, kegs, vats, etc., are used interchangeably. They can also be called vessels. Technically, however, there are some differences among the terms as explained below.
A barrel is a standard measurement that can be dry or fluid, and it can vary in size and weight depending upon the product. The size of barrels varies between countries. For instance, in the U.S. the standard beer barrel is 31 gallons, but in the UK a beer barrel is slightly larger. The capacities and sizes of barrels for other alcoholic beverages is greater, with a bourbon barrel containing 52 gallons, a wine barrel ordinarily with 59 gallons and a cognac barrel with 79 gallons. Usually wood barrels in the U.S. are made of white oak, whereas, in Europe barrels are made of French oak. The materials are similar, but the French Oak requires more time to treat and prepare for barrel making. Barrels for bourbon are charred on the inside and never reused for making that liquor. However, micro-breweries often age and flavor beer using these once used bourbon barrels.
Wood barrels were used for beer and ale in America beginning with the first settlers through the early 20th Century. Not until shortly after Prohibition around 1940 were metal barrels more commonly used, and wood barrels were gradually phased out. The larger vats or tanks could be glass lined to make them more sanitary and easier to clean while requiring less maintenance than wood containers.
The accompanying photos show how beer barrels were stored, filled, washed, distributed and tapped at the Bavarian Brewing Co. in the late 1940s.The first photo is of wood kegs stacked near the Wash Room and the next photo shows barrels entering the Wash Room of the brewery. The other photos include an interior picture on the lower left shown the Rack Room where wood barrels being filled in the foreground, along with metal barrels are in the background, a customer buying barrels of Bavarian's that is being rolled out to his vehicle and a photo of a beer tap, which was was inserted on the "head" or top of a barrel. The close up photo of the middle section of the tap indicates it was made for the Bavarian Brewing Co.
The photos below are the heads of wooden barrels for Bavarian Beer. The first barrel lid below is from the barrel below it and was provided courtesy of Dave Gausepohl. Next to it is a bunge stopper from the same barrel. The other two barrel lids are the top and bottom of different quarter barrels, and were supplied courtesy of Gary Schmeh.