The Difference Between Partial and Full Invert Sugar

Invert sugar syrups are found in a wide range of food and beverage products. They provide important functional characteristics, such as humectancy, making them an essential ingredient in many popular products that are produced at an industrial scale. In this article, we’ll describe the properties and creation of both partially and fully inverted sugar syrup. We’ll also review the types of invert syrup available and their uses, packaging, and nutrition.

Known commonly as invert sugar syrup, invert syrup or simply ‘inverts’, this versatile product is a liquid sweetener manufactured from water and granulated sugar (sucrose). Invert sugar syrup is important in food and beverage production for its low viscosity, high sweetness value, and its ability to be used as a humectant, to depress freezing points and as a flavour attractant.  

The ‘invert’ part of the name of the product refers to the fact that light, when shone through the final product, reflects in the opposite direction from light shone through sucrose. This phenomenon is, in fact, the inspiration behind the Ragus brand name itself, which is sugar spelt backwards.

At Ragus, two types of pure invert sugar syrups are manufactured for industrial applications: fully inverted sugar syrup, and partially inverted sugar syrup. The latter, also called partially inverted refiners’ syrup, includes the world-famous golden syrup that was first formulated in 1883 by Ragus founder Charles Eastick.  

Sucrose, or white crystalline table sugar, is where the creation of invert sugar syrup begins. Sucrose is a disaccharide made from two bonded monosaccharides, fructose and glucose. It’s the process of breaking this bond that results in the creation of invert sugar syrup.  

A sucrose solution is heated in inversion pans at a pH of between five and six. To manufacture a full invert, the process begins with all the sugar required to make the final product being present. Additional sucrose is added later in the process to manufacture a partial invert. Once all the crystals have entered solution, the target temperature is reached and the pH is lower than 1.6, the sucrose will invert into glucose and fructose. Then, once the desired level of inversion is reached, the syrup is neutralised with an alkaline agent.

To manufacture a partial invert, more sucrose is added at this point. After the additional sucrose has dissolved, the brix (the density of sucrose in a solution) will be a maximum of 77% and the polarisation +17 to +23. For full inverts, the brix is 76% with a polarisation of -18 to -22.

Full inverts are much sweeter than sucrose alone – typically by as much as 40%. Partial invert syrups are mixtures that typically contain between 32.5-35.5% sucrose and 42.5-45.5% invert, with full invert sugar syrup being made of 3.5-5.5% sucrose to 71-77% invert.

While invert sugar syrup is primarily used to sweeten a food or beverage recipe, it also has additional functional benefits that are of importance to food and beverage manufacturers.  

One of these is humectancy, or the ability of invert syrup to retain moisture in a baked product, which is an important aspect of prolonging shelf life. In addition to this, invert syrups improve the texture of a product, due in part to the fact that the syrup helps to prevent crystallisation. This humectancy means invert sugar syrups are valued for their use in plant-based products due to this moisture-retaining feature, helping to produce products such as plant-based burgers that have a juicy texture like real meat.

This same prevention of crystallisation makes them useful for producing a smooth, soft texture in icings and fondants. Full inverts depress freezing points, increasing ‘scoopability’ in ice-creams and sorbets, as well as preserving the quality of frozen sauces, cakes and baked goods.

Full inverts are typically up to 40% sweeter than sucrose, so are often found in low-fat products as a replacement for glycerine, enabling sucrose reduction in fruit-flavoured drinks and are key ingredients in cereal bars and mixes.

Products that include invert sugar syrup can be enjoyed as part of a healthy and balanced lifestyle and diet. Invert syrups have an almost identical nutritional profile to table syrup or glucose syrup, containing approximately 45 calories and 13 grams of sugar per tablespoon.

Ragus packages its invert sugar syrups for industrial use delivering principally by bulk tankers and 1000kg intermediate bulk containers (IBCs). For best results and consistent use in food & beverage products, invert sugar syrups should be stored in a cool, dry location, in temperatures of 15-20⁰C.  

To learn more about our products, please contact our Customer Services Team. To see more sugar news and updates, continue browsing SUGARTALK and follow Ragus on LinkedIn.