High maltose corn syrup is a food additive used as a sweetener and preservative. The majority sugar is maltose. It is less sweet than high-fructose corn syrup. It is sweet enough to be useful as a sweetener in commercial food production.The high maltose syrup must contain at least 50% maltose. Typically, it contains 40–50% maltose .By using β-amylase or fungal α-amylase, glucose syrups containing over 50% maltose, or even over 70% maltose (extra-high-maltose syrup) can be produced.

Using of high-maltose corn syrup
High-maltose corn syrup is used as a substitute for normal glucose syrup in the production of hard candy: at a given moisture level and temperature, a maltose solution has a lower viscosity than a glucose solution, but will still set to a hard product. Maltose is also less humectant than glucose, so that candy produced with high-maltose syrup will not become sticky as easily as candy produced with a standard glucose syrup.

Since maltose has a low freezing point, HMCS is useful in frozen desserts. It is also used in brewing, because it has a balanced fermentability, can be added at high concentrations to the wort kettle, increasing throughput, and reduces haze caused by varying malt quality. Another of HMCS's uses is to preserve food by inhibiting fermentation and bacterial growth.