Method for online monitoring of mashing processes using infrared spectroscopy

A method for controlling an enzymatic pre-treatment process, the method comprising:

• a) providing a sample slurry to a system with a tank;
• b) obtaining a sample slurry mixture by:
• adding one or more enzymes to the sample slurry if the sample slurry does not contain one or more enzymes already, or
• possibly adding one or more enzymes to the sample slurry already containing one or more enzymes;
• c) continuously exposing a part of the sample slurry mixture to an infrared (IR) spectrometer on-line and/or in-line;
• d) continuously measuring attenuated total reflectance (ATR) IR spectra of the liquid part (solutes and solvents) of the sample slurry mixture with the IR spectrometer in real time at wavenumbers between 400-3500 cm−1 during the enzymatic pre-treatment process, and
• e) feeding the measured IR spectra to a calculating unit which:
• calculates information relating to specific species present in the sample slurry mixture during the enzymatic pre-treatment process based on the IR spectra, wherein the information relating to the specific species present in the samples slurry mixture is:
• a ratio between the different specific species, or
• a concentration of one or more of the specific species, or
• a degree of polymerization of one or more of the specific species;
• and
• feeds the information relating to the specific species in the sample slurry mixture back to the user or to a tank control system connected to the tank.