Over fifty members gathered at the Society's February meeting to hear Richard Filmer give an illustrated talk about "The Craft of the Cooper". He began by explaining that although the cask is one of mankind's greatest inventions, there is little information recorded about its construction. Invented over four and a half thousand years ago, it was perfected in Roman times.
Staved vessels come in all shapes and sizes although three hoops at the top and three at the bottom is common. With no nails or glue to hold them together they can withstand the pressure of fermenting liquid without leakage. Cask construction has been carried out over the centuries by skilled craftsmen working highly accurately despite having no knowledge of maths; by contrast, customs and excise men used gauging manuals and various instruments to check casks were the correct size. Each cooper was required to add a makers' mark so undersized or leaking vessels could be traced.
Among the slides Richard showed us were impressive sights such as the Guinness factory in 1909, with its stock of a third of a million casks. Oak is the traditional wood for storing alcohol and it can make a special contribution to the taste; this is taken further with scotch which often uses second hand sherry casks to add flavour. Other items stored and transported in casks have included glue, butter, soap, cob nuts, even coca cola until the 1920s. Specialist fishing coopers made cheap softwood one-time use casks for exporting herring and oysters.
Richard showed us photos of workshops he had visited in Eastern Europe and northern Africa, contrasting them with illustrations from hundreds of years ago. The tools and methods of working are remarkably similar. Sadly the craft is dying out, as modern vessels are increasingly made from plastic.
He then ran though the making of a cask. The key is applying heat to the wood which is bent to create a watertight container. The wood is cleft with an axe rather than sawn. It's dressed into a boat shape and then the inside of the stave is hollowed. Staves are fed around the top hoop, then the cask is placed on a fire to draw in the staves at the bottom. For wine the cask can be left charred (to hold the tannins back), but for an oak flavour the inside of the cask is shaved. The final part of the process is fitting the cask head.
As well as casks, staved vessels have been used as clothes tubs, glass washers and for collecting milk. At the other extreme large vats were used in the paper making and chemical industry.
Ellie Morris