(The drawing above comes from “Common Things and Elementary Science in the form of Object Lessons” by Joseph Hassell, (London, Blackie, 22nd ed fully revised 1905) and probably pictures a knife in common use in the earlier part of the nineteenth century. The photographs below are taken from “The evolution of a cork” by F.J. Branscombe in The Wine and Spirit Trade Record, 8 May 1914.)
The social reformer Charles Booth described the process which he witnessed at the works of Mr. Olley in London in 1894. There was a large chimney over a great blazing open fire fed with cork shavings. The “burner” or foreman used tongs to turn the pieces of bark over on a stout iron grill so that they burned on both sides. He had to use skill and judgement to assess how long to burn the cork or it could be ruined. This burning was considered the most skilled part of the job and was usually the last thing to be covered by apprenticeship training. The pieces were put to one side and sprinkled with water to put out any embers. If they were curled they were stood on for a minute or weighted down when first out of the fire. The burning sealed cracks and pores in the cork.
Some premises had a separate area for the burning – a “cork burning house” is mentioned in a lease in Worcester in 1849. In some less urban areas, it seems the cork burning could take place outside. Jessie, the youngest daughter of Thomas Harper (born 1854 and the last working corkcutter in Uttoxeter, Staffordshire) remembered scenes of this from her childhood in the early 1900s.
After burning, the black slabs were stacked for twenty-four hours and then swept to remove the outside coating. This would have been a filthy job and it probably fell to the apprentice . Burnt cork was used by colourmen to produce their black paint. The outside edge of the bark was then trimmed away, leaving the cork ready to be cut into lengths by the “notchers” in a process described in a publication of 1914 as “pushing off”. The width of the strip was determined by the size of the final cork required and the following photograph shows an adjustable measuring device fitted to the knife.
The strips were then cut into squares or “quarters”. Early cork cutters’ knives are shown as long and broad, tapering to the handle and with a square cut end (see illustration on Home Page), though the photos below show a different straight-backed type with a wooden handle.
Hand-cutting enabled faulty pieces of cork to be discarded. When machine cutting was introduced later on, it was not possible to maintain an even quality of cork.
The quarters were then cut into corks. The cutter placed the cube on a peg jutting horizontally from the work bench and rounded it with an upward and rounded cut. The flexibility of the material and the slightly irregular shapes produced ensured a good, tight-fitting product.
An experienced eye and hand were needed to get the best out of each varying thickness and quality of cork. The blackened edges caused by the burning often reduced the uses to which corks could be put. Samuel Carter, writing in 1819, complained that only about twenty-five percent of his cork was suitable for wine and of that a great number of the corks were termed “blacks”, being marked by the burn on both sides, and were only useful for inferior porter. His ingenious idea was to stick thin layers of finer cork together, thus pre-empting cork production methods of the end of the century.
After cutting, further adjustments could be made and the corks were sorted for size.
Machines gained in popularity from the 1860s. The first and most widely-adopted machine was for turning. The cubes of cork were now fixed to a spindle and the machinist stood beside the machine working a treadle with his left foot to spin the cork against his knife blade. Using a machine, daily production per cutter was now increased to between 100 – 150 gross per day. The apprenticeship system gradually fell out of use, and more women were employed.
