Nonlinear Model Predictive Control of Wine Fermentation Kinetics

In the production of wine, most fermentations are completed in successive batches during the 2 month harvest period. Red wine fermentations are usually completed in 10 to 14 days while white wine fermentations are completed in 21 to 24 days. The demand for resources - equipment, water, energy, labor, etc. - in a short time motivates the precise, automated control of the fermentation process. While much research has been performed to evaluate the effect of fermentation temperature on wine chemistry, the ability to research the effect of fermentation kinetics on the resulting wine chemistry and reproduce the results at commercial volumes requires advanced control strategies. In this work, a nonlinear model predictive controller (NMPC) was developed to determine the temperature to achieve a desired fermentation rate. The controller was combined with a pulse cooling and heating strategy to improve energy efficiency of temperature control. The potentials of this approach are demonstrated in simulations and 15 L fermentations.