Crystallization of sugar

Crystallization of sugar
Crystallization of sugar can be a problem in a variety of products. For example, the crystallization of lactose in a glassy state will make nonfat milk difficult to disperse.

If too great an amount of milk solids are added to a frozen dessert, a gritty texture results due to the lactose crystals.

Crystallization of sugar is a major factor in the candy manufacturing industry.

Candies can be divided into two groups crystalline and non-crystalline. Crystalline candies include fudge, fondant and any other candies that have crystals as an important structural component.

Divinity is a crystalline candy but is a special case as crystals are dispersed in foam.

Non-crystalline candies include caramels, brittles, taffies, marshmallows and gum drops.

Marshmallows and gum drops are also special classes of candies as they contain a gelling substance.

Crystallization is a complex process with many interrelated factors. The nature of the crystallizing substance is important for crystallization.

The rate of crystallization is the speed at which nuclei grow into crystals. This rate is dependent upon the concentration of the soluble in the solution, as a more concentrated syrup will crystallize rapidly than a less concentrated syrup.

At higher temperature the rate of crystallization is slow and becomes more rapid at a lower temperature. Agitation distributes the crystal forming nuclei and hastens crystallization.

Impurities in the solution usually delay crystallization and in some cases such as caramels may prevent crystal formation.

Fat and protein decrease the number and size of crystals.
Crystallization of sugar