Posted by Eric Troy on 01 Feb 2015 17:08
Candy comes in many varieties, but they can basically be divided into two categories, sugar based candies and chocolate based candies. Examples of sugar based candies include nougats, fondants, caramels, taffies, and jellies. When using sugar, one of the main things you are really doing is controlling the crystallization of the sugar to achieve different textures. Do you allow the sugar to crystallize? If so, are the crystals large or small? Or, if the candy is noncrystalline, is it smooth and hard like glass, or amorphous, like a marshmallow? Candy making is a science, as well as an art, and to be successful you must follow recipes exactly. However, you may want to know a few basic facts about sugar based candies; mainly the various sugar stages, from soft ball to hard crack stage.
Crystalline Sugar Candies
Crystalline sugar candies have either large or small crystals. Large crystals are really not all that sought after, but an example of a large crystal sugar candy is rock candy, which is quite different than hard candy. Fondant and fudge are both examples of small crystal candy.
Noncrystalline Sugar Candies
Noncrystalline sugar candies offer the most variety. Hard candies, brittles (such as peanut brittle), caramel, taffy, jellies, gumdrops, marshmallows, and chewy candies of any variety are all examples of noncrystalline candies.
Sugars Used To Make Candy
The main sugars used to make candy are sucrose (usually cane sugar), invert sugar, and corn syrup including HFCS. Corn syrup does not crystallize as easily as sucrose, and helps to retard crystallization when added to a sucrose based candy. Invert sugar, also called trimoline or invert syrup, is made by the hydrolysis of the disaccharide sucrose, which splits the glucose and fructose, resulting in a sweeter product that also does not readily crystallize. It also retains moisture, which helps chewy candies stay soft. Maple sugar, brown sugar, molasses, and honey are also used in candy making.
Although a lot can go into making a sugar candy, the basic process involved making a sugar syrup which is boiled to different temperature stages. The temperature the syrup is cooked to, determines the consistency the syrup will cool to. For example, a low temperature could make a fudge or praline, and a very high temperature could make a hard candy or a brittle.
Testing the temperature of the syrup is done by using either a candy thermometer or a cold water test. Since candy thermometers can sometime be tricky and unreliable, many candy makers will use both.
The cold water test is a very old test for checking the sugar stage and was developed long before thermometers were available, as early as the 17th century. The cold water test simply stops the cooking process immediately and cools down the syrup so its consistency can be judged. A small drop of the syrup is dropped into a bowl of cold water, which creates little ball. The consistency of the ball will correspond with a temperature range, and each "stage" is given its own name, based on its hardness. The lowest temperatures, between 225°F and 234°F will not even form a ball, but a thread. This will not really make a candy; it's really just a syrup, great for ice cream and other uses, but not for candy. Only the "ball" stages are included below.
Soft Ball Stage
Temperature: 225° to 240°F.
Description: The sugar will form a ball when it is dropped into the water, but when you take it out, it will loose its shape and flatten.
Candy Types: Fudge, soft fondant, soft caramel, Southern pralines, maple candy.
The video below, from Epicurious, shows how to cook sugar to the soft ball stage. Follow these general steps for cooking sugar to the other stages.
Firm Ball Stage
Temperature: 245° to 250°F
Description: The sugar will form a ball when it is dropped into the water and will retain its shape when you take it out. However, it will be malleable and will lose its shape when pressed.
Candy Types: Caramel, taffy, firm fondant, divinity.
Hard Ball Stage
Temperature: 250° to 268°F
Description: The sugar will form a ball when it is dropped into the water, and it will be very firm and keep its shape well when pressed. However, it will feel sticky. You will have to press very hard to get it to change shape.
Candy Types: Nougat, marshmallows, rock candy.
Soft Crack Stage
Temperature: 270° to 290°F
Description: At this stage, the sugar no longer forms a ball as the syrup is too thick to drop a small amount into water. Instead, it will quickly harden into long threads. The threads will be stretchy and a bit sticky when you take them out.
Candy Types: Butterscotch, toffee, some hard candies.
Hard Crack Stage
Temperature: 298° to 310°F
Description: When you drop it into the water, the sugar will form long threads. The threads will be hard and brittle, and will snap apart very easily.
Candy Types: Hard candy, brittles.
Boiling Points and Safety
Due to the colligative properties of sugar solutions, the boiling point of a sugar syrup can be extremely high. Note that the temperature ranges given above are all much higher than the boiling point of water, which is 212°F (100°C). As the solutions increase in temperature, the concentration of sugar becomes greater, so not only does the temperature increase, but the viscosity. Therefore, candy making can produce severe burns if the hot syrup comes into contact with the skin, as not only is the syrup hotter than boiling water, but the syrup will hold its heat and stick to the skin. Extreme caution should be used when making candy and handling the syrup. Be sure, when you use the water test to check the sugar stage, that the sugar is completely cooled down before pulling the sugar ball from the water.
You can learn more about the science of candy in Candy Bites: The Science of Sweets by Richard W. Hartel and AnnaKate Harte, which reveals candy science and history while profiling some of the word's favorite candies, like Tootsie Rolls, Pixy Styx, Jawbreakers, Jordan Almonds, Peppermint Patties, Junior Mints, and much, much more.
See also: Origin of the Word Candy.
This article contains one or more Amazon affiliate links. See full disclosure.
More Food Science Posts