Influence of the physiological state of the inoculum on fermentation of musts from Pedro Ximénez grapes by Saccharomyces cerevisiae.

Two inocula in different physiological states, namely in the exponential growth phase and in the declining phase were prepared from a strain of Saccharomyces cerevisiae. With these inocula were fermented musts from grapes of the Pedro Ximénez variety, sterilized by filtration. Cell growth and the activity of the enzymes alcohol dehydrogenase and aldehyde dehydrogenase [NADP+ and NAD(P)+] were found to vary with the state of the inoculum. This was reflected in the specific rate of production and, in some instances, in the final concentration of acetaldehyde, acetic acid, ethanol, isoamyl alcohols, phenethyl alcohol and their esters in the wine.