The generation of foam during the production of bioethanol is caused by the presence of foam active substances in the substrates (sugar-, starch based) e.g. proteins and by-products.

Struktol antifoams are effective during the preparation of the substrate, during the fermentation and the distillation process. It is possible to add the antifoam already during the preparation of the mash. Most recommended is the dosage from the top of the fermenter directly onto the fermentation broth or into the circulation pipe, by using an automatic dosage system with foam probes. Further addition is generally not necessary, because Struktol antifoams are carried through the whole process incl. DDGS. In some rare cases a dosage into the distillation and DDGS processing could be necessary.

The dosage rate of antifoam depends on several parameters. Most influencing is the type of process: continuous production requires more antifoam than batch process. But also other process parameters, such as the filling height of the fermenter, substrate in use, etc. have huge influences.

The most effective antifoam product, necessary dosage quantities and best possible addition points depend on a.m. factory conditions and must be found out for each individual factory by carrying out work trials.