Maltose Syrup in Candy Making: Crystallisation Control and Chew

Maltose syrup does two jobs in confectionery that sucrose cannot manage on its own: it holds crystallisation in check and it builds the chew that carries a sweet through packaging, transport and months on a shelf. Both outcomes depend on how maltose behaves at high solids, which is why the grade you buy and the way you dose it matter more than the headline price per tonne.

What maltose brings that sucrose does not

Maltose syrup is a refined starch hydrolysate whose solids are a blend of maltose, maltotriose, glucose and larger saccharides. That blend is the point. Sucrose is a single, highly crystallisable molecule; a syrup with several sugars dissolved in the same water resists orderly crystal formation because the different molecules interfere with one another’s lattice.

High-maltose grades, commonly 40 to 60 percent maltose on a dry basis, also taste markedly less sweet than sucrose, often quoted at roughly 0.4 to 0.6 of sucrose’s sweetness. In a chewy sweet this is an advantage: you can add bulk and body without pushing the product into cloying territory.

Controlling crystallisation

Graining, or the appearance of a sandy texture, happens when sucrose in a supersaturated mass is allowed to form crystals. The classic remedy is doctoring with a glucose or maltose syrup. The syrup’s non-sucrose solids interrupt the sucrose lattice and raise the concentration at which crystals can grow.

The practical lever is the ratio of sucrose to syrup solids. Many chewy formulas start somewhere around 30 to 50 percent of total sugar solids coming from syrup, then adjust upward if the batch still grains or downward if it becomes too soft or too hygroscopic. A high-maltose syrup tends to be less hygroscopic than a high-dextrose one, so it helps a sweet stay dry on the surface rather than weeping in humid conditions.

Building chew, not hardness

Chew is a balance between residual moisture, sugar composition and final cook temperature. Water content controls whether the mass sets glassy or leathery: cook it hotter and you get a hard, brittle candy; pull it slightly cooler and the same recipe turns chewy. Maltose’s lower tendency to crystallise lets you keep more water in the matrix without risking grain, which is how it supports a long, clean chew.

Maltose also slows the hardening that otherwise turns a soft sweet brittle over time, so texture holds on the shelf.

Matching the syrup to the sweet

Different confections want different balances. The table below is a starting point, not a rule; always confirm on your own equipment.

Defects and what they signal

• Graining: too little doctoring syrup, or seed crystals from dirty equipment or scrap rework.
• Stickiness and weeping: syrup grade too hygroscopic, or insufficient cook to the target solids.
• Cold flow: too much residual moisture and too soft a set.
• Excess colour: overheating, long hold times or a high-dextrose syrup that browns readily.

Handling on the line

Maltose syrup is viscous and dense; it is easier to pump and meter when kept warm, typically around 25 to 35 degrees Celsius, though prolonged high-temperature holding will darken it. Add the syrup early enough to dissolve completely before the boil, weigh it rather than estimating by volume, and keep transfer lines clear of dried material that could seed a batch.

Frequently Asked Questions