Winemaking by barley supported yeast cells

A new biocatalyst was prepared by immobilisation of Saccharomyces cerevisiae AXAZ-1 yeast cells on whole barley grains. This biocatalyst was used for 30 repeated batch fermentations of glucose and grape must at various temperatures. The biocatalyst retained its operational stability for a long period and it proved capable to produce dry wines of fine clarity even at extremely low temperatures (5 °C). The produced wines were analysed for volatile byproducts by GC and GC–MS. The results showed an increase in the number and amount of esters produced when immobilised cells were used. In addition, an increase in the percentages of esters and a decrease in those of alcohols with the decrease of fermentation temperature were reported.