Commercial processing of starch to mono-and oligosaccharides depends on the availability and properties of the applied enzymes such as -amylase, glucoamylase, -glucosidase and xylose isomerase. Each of these enzymes has a different pH and temperature optimum for use. Therefore starch processing is carried out in the stages of liquefaction, saccharification, and isomerisation. This article discusses the application of thermostable enzymes leading to higher quality products and lower production costs caused by the simplification of the processing.