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 cooled ball becomes harder The most concentrated syrups make a cracking sound as they turn into hard, brittle threads Each of these stages indicates a particular temperature range and suitability for a particular kind of candy (see box below) Syrup Boiling Points Depend on Sugar Concentration The boiling point of a sugar solution increases as the concentration of sugar increases This graph shows the relationship between boiling point and sugar concentration at sea level The Heating Rate Accelerates During Cooking As we cook a sugar syrup, most of ... kind of candy (see box below) Syrup Boiling Points Depend on Sugar Concentration The boiling point of a sugar solution increases as the concentration of sugar increases This graph shows the relationship... ball becomes harder The most concentrated syrups make a cracking sound as they turn into hard, brittle threads Each of these stages indicates a particular temperature range and suitability for... This graph shows the relationship between boiling point and sugar concentration at sea level The Heating Rate Accelerates During Cooking As we cook a sugar syrup, most of