Barley sugar

Definition and stakes

Robert Wells The Bread and Biscuit Baker's and Sugar-Boiler's Assistant

Put some sugar in a pan with water and place it on the fire to boil; when it is at the feather add a little lemon juice and continue boiling to the caramel; when done add a few drops of essence of lemon. Pour it on a marble slab previously oiled, [76] cut into strips. When nearly cold take the strips in your fingers and twist them, and when quite cold put them into tin boxes and keep them closed down. The reason that barley sugar is so named is that it was originally made with a decoction of barley.
Source: Gutenberg

J. H. Payne Bee-keeping for the Many; or, The management of the common and Ligurian honey bee (1870)

To Make Barley-sugar.—Put two pounds of loaf sugar into a saucepan with half a pint of water, and two spoonfuls of the best vinegar; put it on a gentle fire, let it boil till the syrup becomes so thick that the handle of a spoon being dipped into it, and then plunged into cold water, the syrup upon the handle is found to be quite crisp; when this is the case it is sufficiently boiled. Having an earthen dish or marble slab in readiness, well- 26 - buttered, pour the syrup upon it, and, when sufficiently cool to handle, clip it with scissors into strips the size desired.
Source: Gutenberg

Portrait of Eliza Acton Eliza Acton Modern cookery for private families (1882)

For barley-sugar likewise it must be constantly stirred, and carefully watched after the lemon-juice is added. A small quantity should be dropped from time to time into a large basin of cold water by those who are inexperienced in the process; when in falling into this it makes a bubbling noise, and if taken out immediately after, it snaps clean between the teeth without sticking to them, it must be poured out instantly: if wanted for sugar-spinning, the pan must be plunged as quickly as possible into a vessel of cold water.
CARAMEL.
(The quickest way.)
Source: Gutenberg

Get perspective with Kwize: daily news enlightened by great literature