Accelerated Aging1 of Fino Wines by Submerged Culture using Film-Forming Yeasts

Abstract

The behavior of 20 flor yeasts from Andalucia, Spain, were studied for their ability to acclimatize to a medium with a high alcoholic content. The yields of acetaldehyde and the ability to metabolize acetic acid were also measured for each yeast.

Initial test conditions were about the same as in the Spanish cellars for ordinary flor studies (15% v/v alcohol content and controlled temperatures at 18°C). Inoculalion was followed with aeration in a 30-liter fermentor at atmospheric pressure.

There were marked differences among species and strains of yeasts in response to temperature and the amount of initial inocula. The acclimatization period for Saccharomyces cherensiensis V-24 was four days. The increase in acetaldehyde obtained after 41 hours with an inoculum of 455 mg/l (dry weight) of adapted yeast was 400 mg acetaldehyde/l over the initial content. Recluction in volatile acid under the same conditions was 0.37 g/l.

Several samples of treated wine have been compared by a panel of tasters to a fino wine three years old aged under a yeast film according to the traditional methods.