Air classifying sugar grinding mills are used in the processing of fondant solutions. Forming as a paste or cream, fondant consists of solid, liquid, and gaseous phases that combine saccharose crystals, saturated saccharose solution, and glucose sugar. Food processing plants use fondant to coat material for confectionery, chocolate, or pastry products. Because of its sensory properties and the ease with which machines like sugar grinding mills can work with the sweet, viscous substance, it’s long been at the heart of many confectionery recipes. 

How is Fondant Made?

A fondant mixture is made up of very fine sugar crystals, all 280 mesh (under 53 microns) and smaller. Air classifying sugar grinding mills or other types of reducing mills are used to reduce sugar to this level, breaking granules down to between 200-325 mesh (44-75 microns).

This saturated solution consists of three to four parts powdery sugar particles mixed with one part glucose syrup, which is then dissolved into water. This solution is then heated to 230-234 degrees Fahrenheit (110-112 degrees Celsius), after which it’s boiled further to 242-246 degrees Fahrenheit (117-119 degrees Celsius) until it’s approximately 88% concentrated. 

The syrup is then cooled to 100-108 degrees Fahrenheit (38-42 Celsius) before being delivered to a beater-cooler. This super-saturated solution is then agitated and cooled in a large rotating drum, which is water-cooled internally or via a water-jacket tube with a screw inside. This process removes excess sugar and creates deposits of minute sugar particles that are then removed to keep them from dissolving back into the solution. 

In an industrial environment, giant fondant-making machines capable of producing 1000 kilograms or more per hour beat this cooled syrup so that it rapidly crystallizes into fondant syrup. At this point, the cooled syrup’s sugar particles are reduced to about 950-1250 mesh (about 10-15 microns) due to heat and agitation. When dry, the finished product will contain 5% invert sugar (a combination of glucose and fructose made from sucrose, combined with a substance that prevents crystallization, such as citric acid, starch syrup or cream of tartar). 

Uses for & Types of Fondant Sugars 

This saturated solution of sweeteners is made up mostly of sucrose that’s reduced to below 280 mesh (44 microns), with the balance being corn syrup and invert sugar. Used in the confectionery, food, and baking industries, fondant can be used for the following:

  • Candy or pastry cream centers.
  • Edible icing used for decorating cakes. 
  • Remelted to be cast into molds or chocolate shells. 
  • As a food additive to reduce moisture loss.
  • As a base for smooth confections.

While discussing fondant generally, it has various forms, each with distinctive processes and used for varying purposes, for which sugar grinding mills are an integral part of the operation.  

Dry Fondant Sugar by Co-Crystallization

Co-crystallization involves incorporating a second ingredient through a process involving spontaneous crystallization. Acting as a base, the purified sucrose in this mixture forms a new structure with unique properties. It is composed of 95% sucrose, and 5% invert sugar on a dry weight basis, with crystals of less than 370 mesh (40 micron). 

Dry Fondant Sugar by Micro-Pulverization

Manufactured from selected sugar and combined with trace moisture, this composition blends sucrose (97.5%) with low DE cereal solids (2.5%) as an additive to thicken and stabilize the mixture. Granulation here reaches 325 mesh (44 microns). Introducing a DE cereal solid like maltodextrin allows properties that include:

  • Water solubility combined with low sweetness for filler creams, though with less stickiness. 
  • Less intense caramelization during baking. 
  • Assisting sugar crystals to adhere well to non-creamed wafers. 

Fondant candies prepared by this cold production process simply mix the fondant sugar with liquids to create various creams.  

Icing Sugar

While not fondant sugar, the baking industry uses fondant as a base when making high-grade icing, frosting, or glaze. Bakers use fondant sugar to eliminate grittiness, common in confectioners’ sugar, which has grains greater than 325 mesh (44 microns). Essentially, sugar with crystals smaller than this is considered icing sugar, which is combined with low-DE cereal solids, such as maltodextrin, in sugar grinding mills. Generally, icing sugar is comprised of 89% sugar, with the rest consisting of low-DE cereal solids and particle sizes ranging from 200-325 mesh (44-74 microns).

Sugar Grinding Mills & Fondant Sugar Production

When it comes to fondant sugar production, air classifying sugar grinding mills operate similarly to fine grinders. They combine impact milling of sugar crystals with internal air classifiers that allow the machines to precisely separate and recirculate the powdery sugar particles based on size. Such mills can reduce sugar particles to a very fine 12X category that ranges in size from 200-325 mesh (44-74 microns), which easily incorporate into fondant mixtures. 

This may require tailoring particulate properties when handling dried material during sugar processing, however. By using state-of-the-art air classifying mills for sugar grinding, manufacturers can also make precise adjustments through use of on-line capabilities. As industrial reduction machinery, air classifying mills are designed to incorporate a two-stage closed circuit. The sugar grinding mill’s chamber is combined with an air classifier into a single unit. 

Using impact, air classifying mills reduce material size with high-speed grinding rotors while a screen frame fitting around the rotor uses serrated jaws and screens to provide additional shear and impact as the sugar particles are accelerated. Independently controlled, the air classifier spins off the sugar particles that are too large, recirculating them into the mill’s grinding chamber to reduce their size further. Because of this feature, air classifying sugar grinding mills outperform other impact mills, especially when narrower particle distribution is needed. 

Prater’s Air Classifying Mills

Prater Industries’ air classifying mills have become a workhorse in production lines across many industries. Besides acting as sugar grinding mills, they are used widely in the food processing, pharmaceutical, mining, recycling, and chemical industries. In fact, Prater’s air classifying mills are essential in any manufacturing process that requires particle reduction, including for:

  • Clay dyes
  • Coatings on pet food
  • Cornstarch 
  • Dextrose
  • Dry chemicals
  • Dry sorbent powders
  • Flour
  • Food ingredients
  • Freeze-dried meats
  • Gelatin
  • Gluten 
  • Gypsum
  • Limestone
  • Pharmaceutical agents
  • Pigments
  • Soy protein
  • Talc 
  • Whole grains

Developed to handle specific operations for handling bulk materials, Prater’s air classifying mills have become invaluable in innumerable processes requiring particle reduction. Specifically, Prater’s air classifying mills are designed with large access doors that make it much easier to clean and maintain. By combining an air classifier with an impact mill, Prater’s versatile dual-stage grinder can meet various production challenges. Contact Prater’s knowledgeable sales and technical personnel to learn more about the company’s sugar grinding mills and other reduction equipment, which can be tailored to meet your specific needs.

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