When boiling a heavy syrup for any length of time, the water evaporates and the sugar becomes concentrated. The syrup thickens and flows less quickly. The changing concentration of sugar gives the syrup exciting characteristics which can be put to many uses. Cooled syrup can be malleable or, if boiled long enough, brittle. Before it sets, the syrup can be worked in various ways, to part-crystallize the sugar and form a paste or to be spun into exciting decorations, for instance.
Soft-ball (116-118°C) A little blob of syrup holds its shape and is soft. Syrup boiled to this stage is used for Italian Meringue and buttercream icing.