Abstract: Washing process in an industrial washing machine, whereby a property of the wash liquor is measured which is dependent on the concentration of detergent product therein, and detergent product is added to the wash liquor, dependent on the property, characterized in that the wash cycle comprises a first period (t.sub.1) in which product is added during a fixed time period to obtain a high concentration in the wash liquor or until the measured property reaches a high set point where it is maintained by gradually adding detergent product, and a second period (t.sub.2) in which the property is kept at a low set point. There is also provided a device for controlling the dosing of detergent product to the process.