Treacle

Historically, the Middle English term treacle was used by herbalists and apothecaries to describe a medicine (also called theriac or theriaca), composed of many ingredients, that was used as an antidote for poisons, snakebites, and various other ailments. Triacle comes from the Old French triacle, in turn from (unattested and reconstructed) Vulgar Latin *triacula, which comes from Latin theriaca, the latinisation of the Greek θηριακή (thēriakē), the feminine of θηριακός (thēriakos), 'concerning venomous beasts', which comes from θηρίον (thērion), 'wild animal, beast'.

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 (i.e., until sugar crystals precipitate out) in a vacuum pan, forming a low-grade masse cuite (boiled mass) which is centrifuged, yielding a brown sugar and a liquid by-product, treacle.

Black treacle naturally contains relatively high levels of sulphite (>100 ppm, expressed in sulphur dioxide equivalent). These levels are deemed safe for the majority of the population. However, some allergic and respiratory reactions have been reported particularly amongst asthmatics, such that the United States Food and Drug Administration requires that levels over 10ppm, i.e. >10 mg/kg, be declared on the ingredients label.