The reactor is filled with concentrated fruit juice and heated. In order to achieve a higher density, the water content is reduced through evaporation. As soon as the required Brix (density) value is reached, the syrupy fruit juice concentrate is pumped out. The concentrate is then pumped over to a filling machine to be stored in barrels or to a cooling machine where it is hardened and granulated. Reliable density measurement is used to monitor quality in the production process.