of sugar and water until it boils, and then keep
it at the boil and watch its temperature. At
235ºF/113ºC, or about 85% sugar, the cook
can stop the concentration process and make
fudge; at 270ºF/132ºC, or 90%, taffy; at
300ºF/149ºC and above, nearing 100% sugar,
brittles and hard candies.
The Cold-Water Test Although it was
invented 400 years ago by Sanctorius, the
thermometer has been a common household
appliance for only a few decades. Beginning
in the 16th century and continuing to this day,
confectioners have used a more direct means
of sampling the syrup’s fitness for different
candies: they scoop out a small amount, cool
it quickly, and note its behavior. Thin syrups
will simply form a thread in the air.
Somewhat more concentrated syrups form a
ball when dropped into cold water, and the
ball will be soft and malleable between the
fingers; as the concentration increases, the