Historically, the Middle English term treacle was used by herbalists and apothecaries to describe a medicine, composed of many ingredients, that was used as an antidote treatment for poisons, snakebites, and various other ailments. Triacle comes from the Old Frenchtriacle, in turn from Vulgar Latin*triacula, which comes from Latintheriaca, the latinisation of the Greek θηριακή, the feminine of θηριακός, "concerning venomous beasts", which comes from θηρίον, "wild animal, beast".
Production
Treacle is made from the syrup that remains after sugar is refined. Raw sugars are first treated in a process called affination. When dissolved, the resulting liquor contains the minimum of dissolved non-sugars to be removed by treatment with activated carbon or bone char. The dark-coloured washings are treated separately, without carbon or bone char. They are boiled to grain in a vacuum pan, forming a low-grade massecuite which is centrifuged, yielding a brown sugar and a liquid by-product—treacle. Black treacle naturally contains relatively high levels of sulphite. These levels are deemed safe for the majority of the population, but some allergic and respiratory reactions have been reported particularly amongst asthmatics, such that the American FDA requires that levels over 10ppm, i.e. >10mg/kg, be declared on the ingredients label.
In culture
A traditional Cornish fisherman's celebratory drink is "Mahogany", made from two parts local gin—now usually Plymouth Gin—mixed with one part black treacle. In chapter 7 of Lewis Carroll's Alice's Adventures in Wonderland, the Dormouse tells the story of Elsie, Lacie, and Tillie, who live at the bottom of a well. This confuses Alice, who interrupts to ask what they ate for sustenance. "The Dormouse again took a minute or two to think about it, and then said, 'It was a treacle-well.'" This is an allusion to the so-called "treacle well", the curative St. Margaret's Well at Binsey, Oxfordshire.
History
UK production is almost exclusively from Tate & Lyle. Black treacle - Fowlers and Blackie's both referred to it as treacle. Tate & Lyle acquired both companies. Treacle before WW2 could be seen served from a barrel and transferred to the customers' container with a 'stick'.