This section is from the book "The Illustrated London Cookery Book", by Frederick Bishop. See also: How to Cook Everything.
The various purposes to which sugar is applied require it to be in different states; these are called degrees. They extend to the number of thirteen, and are named in the following order:
Replace the clarified sugar in the preserving-pan to boil gently, take a drop of it on the thumb, touch it with the forefinger; if on opening them it draws to a fine thread, and in breaking forms two drops on each finger, it is at the right point.
A little more boiling brings it to this point., when the thread will draw further before it breaks.
At this point the thread may be draw as far as the span will open without breaking.
On still increasing the boiling little raised balls are formed on the surface of the sugar.
Take up some of the sugar on a skimmer, and drop it on the rest, when it should form a slanting streak on the surface.
Boil it yet a little longer; the streak or tail is now larger, and it has reached this point.
Take out a skimmerful of the sugar, blow through it and small sparks of sugar will fly from it.
The same proof as above; the sparks should be larger and stronger.
Take the sugar in the skimmer as before; give it a shake, and if the sparks are large, and adhere together on rising, it is at the right point.
Dip your fingers in cold water, and then into the sugar instantly, and again into the water, when the sugar will roll into a ball which will be supple when cold.
At this point the ball or bullet will be harder when cold than the last.
Prove as above; the bullet should crumble between the fingers, and on biting will stick to the teeth.
At this point it should snap clean when bitten. This point is very difficult to attain, for in increasing the height, the sugar is apt to burn, it is better therefore to try the proof very frequently.
Another caramel is much used by the confectioner, and is of a deep colour, it is made by putting a little water to the sugar, and boiling it without skimming or otherwise touching the sugar till of the right colour, then take it off, and use immediately.
If on preparing the sugar, you happen to miss the right point, add a little cold water, and boil once more.
The skimmer should never be left in the preserving-pan after the sugar is clarified, nor after the scum is removed.
Be very careful not to stir or disturb the sugar, as that would cause its diminution.
In boiling the sugar, particularly the two last degrees, the sugar is continuously rising and falling,, and on falling leaves marks on the side of the pan, which the heat of the fire would soon burn and thereby spoil the whole of the sugar. To avoid this have by the side of you a pan of cold water, and a sponge, upon which, wipe the sides of the pan carefully the instant after the sugar has fallen.
 
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