Industrial wine making:: Comparison of must clarification treatments

Three solid-liquid separation techniques, vacuum filtration, centrifugation, and settling, were used prior to fermentation to clarify musts from two different white grape varieties (Vitis vinifera var. Parellada and Macabeo) on an industrial scale. Solid content and ammonium and amino acid concentrations were analyzed before and after clarification, and sugar, ethanol, glycerol, n-propyl alcohol, isoamyl alcohol, and ethyl acetate compositions were monitored during the fermentations to determine how the clarification treatment affected the fermentation rate and higher alcohol production. The results show that vacuum filtration gives musts with the lowest solid content, and this means longer fermentation time, lower isoamyl alcohol production, and greater ethyl acetate formation. However, the three industrial clarification techniques studied caused no significant differences in the initial amount of ammonium nitrogen and total free amino acids.