What is the sugar chemistry of making candy?

Feb 14th, 2021 | by  Sarah Shakeel

Candies fascinate every age group. They bring out our inner child. From a long time, candies have been made and improvised. There are 20 different varieties of candies, each with a distinct taste.


Candies are available in the form of bubble gum, cotton candy, bar, caramel candy, lollypop, gummy, etc. These have become one of the favourite sweets of children and youngsters. But do you know the science behind making candies?

What is the composition of candies?

Sugar is the major component of candies. Sugar can be derived from cane or beet in the form of sucrose which is a reducing sugar. Apart from sugar, many candies contain caramel which is derived from caramelizing sugar, some candies include fudge which a crystallized form of sugar. Along with these sweetening agents, candies also contain parts of milk, chocolate, water, cocoa powder and marshmallows. Candies are found in a wide range of varieties due to the combination of these ingredients. 


The chemistry behind candy making

Candy became famous during the 19th century. It was the time when candy making was purely home-based. It was made by dissolving sugar in water or milk. With the beginning of the industrial revolution and the growing popularity of candies, various industries were set up for manufacturing. With the advancement in technology and machinery, candies are now manufactured in factories.

Making of candies includes certain chemical reactions of sugar molecule that is sucrose. Sucrose is a disaccharide and reducing sugar, which on hydrolysis gives two units, one of glucose and other fructose. When a sucrose molecule is heated, a browning or Maillard reaction occurs which creates a brown coloured caramel. This process is called caramelization. 


The process of candy preparation involves the binding of water molecules with sucrose molecules which results in the formation of the crystal lattice of sugar in the solution.

Some candies consist of a hard and crystalline surface; they are a result of the crystallization reaction of sugar. When a supersaturated sugar solution (a solution made by dissolving sugar in water till it becomes immiscible) is subjected to low temperature, sugar crystals appear. This makes a candy hard. Some candies do not include crystallization in their preparation, they use agents like glucose, fats, and acids to prevent crystallization. 


Candies are classified into 2 main categories- crystalline and non-crystalline. Nougat and fondant are crystalline candies that are hard in structure. Crystals are obtained when cooling of the candy syrup occurs. It does not need any stirring. A non-crystalline candy consists of a soft and fluffy texture. The smooth texture is achieved by interfering agents. It requires a high temperature to boil the candy syrup and when cooling occurs, the crystals are re-dissolved into the sugar solution with constant stirring. Cotton candies, lollipops, toffees are some examples of non-crystalline candies.

Nutrient content of candies

Carbohydrates and fats constitute a major part of candies. Candies contain around 535 calories per 100 gm. The sugar content is around 20% while the total fat content is 45%. Other nutrients include protein which is 15%, and some minerals constituting 10-15%. Candy is said to be an empty calorie food as the nutrients we get from it are negligible. Candies have a range from higher to lower calorie candies. Some examples are:

  • Low-calorie candies: skittles, candy cane, cotton candy and marshmallow candies. They contain low fat.
  • Medium-calorie candies: saltwater taffy, Twizzlers strawberry, peppermint pattie. They have below 200 calories.
  • High-calorie candies: chocolate bars, kit kat, snickers, Twix. They have a large proportion of calories.


Candies appeal to most of us but consumption in a large amount is harmful. It contains a lot of sugar which can cause:

  • Tooth decay when oxidization takes place
  • Increase cholesterol levels
  • It can make children obese
  • Weakened immunity

It is beneficial to eat candies occasionally and especially children need to be given in moderation. Make candies at home and control your calorie intake. It just needs sugar and milk/water to be boiled and cooled. Mould the candies in different shapes and enjoy your meals with their sweetness.



Sarah Shakeel

Sarah Shakeel

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