Lyophilization was compared with slant culturing and with storage under oil as a means of preservingSaccharomyces uvarum.Several types of suspending media were tested, and horse serum, the glucose-supplemented horse serum“Mist, desiccans,”and skim milk were used for a long-term study. A range of shelling temperatures was investigated and−30°C was found optimal in terms of viability. Samples were revived every 3 months for a 24-month period. Mutation rates, assimilation and fermentation characteristics, growth requirements, gas-liquid chromatographic profiles from CS2extracts of experimental fermentations, and organoleptic comparisons of pilot beers all indicated that lyophilization was comparable to the other storage methods. Although viability decreased significantly over the test period, sufficient normal, viable cells survived to maintain a reliable stock.