The Science Behind Crystallization of Sugar

Crystallized sugar, resembling damp, white sand, often occurs due to improper melting during cooking. Even a single sugar crystal can catalyze a chain reaction, turning syrup into a mass of crystals. This phenomenon arises when granulated sugar particles encounter melted ones or when excessive agitation disrupts the cooking process.

To mitigate crystallization, chefs employ inversion, chemically transforming regular sugar into a crystallization-resistant form. Adding acids like cream of tartar or lemon juice, or substances like glucose or corn syrup during cooking, facilitates inversion. Additionally, brushing the pan's sides with water while cooking helps prevent crystallization.

Interestingly, controlled crystallization is embraced in certain culinary contexts, yielding smooth textures in confections like fondants and fudge. This controlled process involves the formation of numerous microscopic sugar crystals. Conversely, in non-crystalline confections like caramels, hard candies, and toffees, crystallization must be meticulously avoided.

Advancements in culinary science have further refined techniques to manage crystallization. Modern chefs experiment with precise temperature control, leveraging thermometers and specialized equipment to achieve desired textures. Additionally, the exploration of alternative ingredients and innovative methods continually expands the repertoire of crystallization management in culinary arts.

Understanding the intricacies of crystallization not only enhances the quality of confections but also underscores the fusion of artistry and science in gastronomy. As chefs navigate the delicate balance between crystalline and non-crystalline textures, they continue to push the boundaries of culinary creativity, offering delightful experiences to gastronomes worldwide.
The Science Behind Crystallization of Sugar

Caramelization of sugars

Caramelization is what happens when any sugar is heated to the point that the molecules undergo chemical reactions with oxygen in the air and with each other – the molecules either break apart into smaller molecules, or combine with one another to make larger molecules. The result is a very complex, brown colored mixture that normally call caramel.

Caramelization occurs in food, when food surfaces are heated strongly, e.g. the baking and roasting processes, the processing of foods with high sugar content such as jams and certain fruit juices, or in wine production.

Sugar is caramelized when it is melted into a clear golden to dark brown syrup, reaching a temperature from 320 to 356 degrees F. It goes through many stages which are determined by the recipe being made.

At 338 degrees F, the sugar syrup begins to caramelize creating an intense flavor and rich color, from light and clear to dark brown. Depending upon when the cooking stops and it cools and hardens, caramel textures can range from soft to brittle. A soft caramel is a candy made with caramelized sugar, butter and milk. Crushed caramel is used as a topping for ice cream and other desserts.

The large brown molecules (caramelin, caramelen and caramelan) are what give caramel its color, its viscosity and its stickiness. The aroma molecules give caramel its flavor.

Caramel colors, i.e. ammonia caramel, ammonia sulphite caramel, and caustic caramel are the most widely used food additives and are found as coloring agents in a wide range of foods and beverages.
Caramelization of sugars

Crystallization process of sugar

Crystallization is a process of formation of solid crystals precipitating from a solution through a natural or an artificial method. Crystallization is a separation process, widely applied in the chemical and pharmaceutical industry. The principle of crystallization is based on the limited solubility of a compound in a solvent at a certain temperature, pressure, etc. A change of these conditions to a state where the solubility is lower will lead to the formation of a crystalline solid.

All crystallization processes are aimed at creating a supersaturated solution or melt. The super-saturation is the driving force under whose influence new crystals are formed and present crystals grow.

Crystallization remains the preferred means of separating sugar from the impurities. As the sugar crystal is extremely selective as to what it builds into its lattice, theoretically absolutely pure crystals can be produced by crystallization.

Sugar has a very high solubility in water (solutions range from 10 to 30% water content) so solutions are very viscous. This is a significant constraint in processing. Having prepared sugar crystals, it is necessary to separate them from the mother liquor (molasses). This is carried out in high speed centrifuges.

In making icings, frostings, or candy like fondant and fudge, it is necessary to crystallize the sugar solution. For crystallization to occur, nuclei must form in the solution. To these nuclei the material of the solution is added to form crystals. Both the rate of formation of nuclei and the rate of crystallization are affected by the nature of the crystallizing substance, the concentration, the temperature, agitation, and the impurities present in the solution.
Crystallization process of sugar

Crystallization of sugar

Crystallized sugar looks like damp, white sand. It happened often as a result of not being properly melted during cooking. If even one sugar crystal comes into contact with cooked syrup, it can start a chain reaction that turns the whole thing into a mass of sugar crystals.

Crystallization can occur when granulated particles of sugar come in contact with melted particles, or when the melted sugar is agitated too much during cooking.

This can be controlled by a process called inversion. Inversion is a chemical change to regular sugar into another form of sugar that resists crystallizing.

If an acid, such as cream of tartar or lemon juice, is added to a syrup before or during cooking, some of the sugar is inverted. Glucose or corn syrup may also be added to control crystallization in boiling syrup. 

Crystallization also may be prevented by brushing down the sides of the pan with water during the cooking process.

Sugar is purposely crystallized during the cooking process for crystalline confections like fondants and fudge because controlled crystallization forms thousands of microscopic sugar crystals that create smooth and creamy texture.

Conversely, crystallization must be avoided during the production of non-crystalline confections such as caramels, hard candies and toffees.
Crystallization of sugar

What happened during caramelization process?

The process refers to a specific stage in the sugar cooking process.

Caramelization results from heating sugars. Sucrose heated in a dry pan will start to let into a clear, viscous mass when heated to about 320° F (160° C).

If heating continuous to 338 F (170 C), the melted sugar mass will become smooth and glossy and start to caramelize.

The longer it is allowed to cook, the darker the sugar will became. As it darkens, the sugar develops its characteristics caramel flavor.

Caramelization is an example of non-enzymatic browning involving the degradation of reducing sugars without the condensation step.

When sugars are heated, a series of complex chemical reactions occur that break down sugar into smaller fragments. These smaller molecules evaporate easily and trigger human sense of smell, providing the wonderful aromas associated with caramelized sugar.

Seventy five percent to eighty five percent of the caramel produced in the United States is used in soft drinks, particularly root beers and colas.

Caramelized flavors are very important flavor components in many styles of beer and can form the backbone of a beers ability to pair successfully with many foods.
What happened during caramelization process?