THE CRACK.--Follow the directions given for the ball. Slip the sugar from off the stick, still holding it in the water, then press it between the finger and thumb; if it breaks short and crisp, with a slight noise, it is at the crack.
CARAMEL.--To obtain this degree, it requires care and attention, and also to be frequently tried, as it passes speedily from the crack to the caramel. Try it as before directed, and let the water be quite cold, or you will be deceived. If, on taking it off the stick, it snaps like glass, with a loud noise, it has attained the proper degree; it will also, when it arrives at this point, assume a beautiful yellow color; after this it will speedily burn, taking all the hues, from a brown to a black; therefore, to prevent this, dip the bottom of the pan into a pail of cold water, as soon as it comes to caramel, as the heat which is contained in the pan and sugar is sufficient to advance it one degree; also, be careful that the flame of the fire does not ascend round the sides of the pan, which will burn it.
In boiling sugar keep the top of the pan partly covered from the time it commences boiling until it has attained the ball or crack; the steam which rises being again thrown on the sides, prevents the formation of the crust or crystals.
To prevent its graining, add a little of any sort of acid, when it is at the crack--a table-spoonful of common vinegar, four or five drops of lemon-juice, or two or three drops of pyroligneous acid: any of these will have the desired effect. This is termed greasing it. But remember that too much acid will also grain it; neither can it be boiled to caramel if there is too much. A little butter, added when it first commences boiling, will keep it from rising over the pan, and also prevent its graining. About as much cream of tartar as may be laid on a sixpence, and added to seven pounds of sugar, with the water, or equal quantities of cream of tartar and alum in powder, added when it boils, will also keep it from candying. If sugar is poured on a slab that is too hot, it is very apt to grain; this is frequently the case after several casts have been worked off in rotation; therefore, when you find it inclined to turn, remove it to a cooler spot, if possible, and not handle it any more than is necessary.