In the Mediterranean regions of Europe, large kiln-fired pottery jars had always been, and continued to be, the standard for storing just about anything. But when the northern regions were settled during the Middle Ages, kiln technology was almost non-existent. It seems that early Germanic pottery was just buried in a fire’s ashes, which was only sufficient to make small jugs or bowls.
However, the continent was thickly covered with oak trees. Before the Christian era, Frankish, Danish and Swedish carpenters had learned to make straight oak staves into round, water-tight containers. Some ship burials have small barrels or buckets dating back to 500 and 600 AD.
Barrels were made from straight or curved staves. Straight staves could make an open barrel, in other words a bucket or tub. They could also make a barrel that was closed on both ends, but only to contain things that were not going to exert any pressure on the walls. Alcoholic drinks like wine and ale would break the staves of an ordinary straight barrel.
Straight staves had to be fitted into a circle, with their edges tapered so that they naturally formed a circle when tightly put together. Carving these staves was not very difficult or time-consuming. The earliest straight-stave barrels and buckets used flexible wooden bands to hold the staves together. Iron technology became developed in medieval Europe, so most medieval barrels used iron hoops to hold the staves in place. The cooper slipped the hoop over the narrower end of a bucket or tub, then hammered it toward the wider part until it fitted too tightly to budge.
Because barrels with straight staves couldn’t be used for alcohol, their makers were known as “dry coopers.” Dry coopers made casks to ship everything from soap, flour, fish, salt, newly-minted coins, and eventually gunpowder. Soap and fish were not entirely dry, so their barrels had to be made with some care not to leak. But many other dry barrels were made of cheap, thin wood. They were expected to last through more than one shipping voyage; coopers were permitted to re-use barrels as long as they had not held soap, tar, or oil. But nobody expected these dry kegs to last more than a few years.
“White coopers” made buckets and tubs used widely in dairy. Wooden milking buckets used straight staves and iron (or wooden hoops); traditionally, one stave stuck up higher than the others to use as a handle. Buckets intended for water usually had two staves standing higher, with holes drilled, so that shoulder yokes could be attached. Cheese-making tubs, cheese molds and butter churns were all modified straight-stave barrels.
Dry coopers made barrels to exact sizes; their Coopers Guild brands certified that the barrels were not slightly smaller than the standard. It was illegal to use a commercial barrel that was not branded by its maker, since then nobody could certify the size. White coopers, on the other hand, did not have to meet regulations in the same way. Their buckets and churns could be traditional or convenient sizes. Some coopers made tubs as large as they could manage, since commercial baths bought these huge tubs for several people to bathe in at once. Tubs didn’t need to be precise in size, but they definitely required two higher staves with holes, so that several men could carry the huge, heavy tub on a pole through the streets.
next: wet coopers