Indirect Evaluation of Microbial Spoiling Activity in Grape Marcs by Near-Infrared Spectroscopy

Outlining a selection procedure for Saccharomyces cerevisiae isolated from grape marc to improve fermentation process and distillate quality

“…Indeed, many studies reported that biodiversity of S. cerevisiae can vary according to the vineyard, production site (Valero et al, 2007;Vezinhet et al, 1992), grape variety and winemaking practices (Pretorius, 2000). In all cases fermented grape marc were sampled in order to isolate a high number of S. cerevisiae strains as several studies (Bovo et al, 2011a(Bovo et al, , 2013 reported that after 4 and 15 days of storage yeast population is almost completely dominated by S. cerevisiae.…”

“…Physical and chemical favourable conditions (relatively high pH values with respect to the must, increasing temperature and nutrient content) occurring during this phase, often lead to an uncontrolled proliferation of spoilage microorganisms responsible for side fermentations (Bovo et al, 2013). For this reason spiritmakers have adopted different precautions to assure a correct development of the fermentative process, first of all the rapid delivery of marc from winery to the distillery and the use of modern storage systems, such as sealed plastic tunnels, to reduce the amount of oxygen (Da Porto, 2002).…”