Survival of wine microorganisms in the bottle during storage

Microbial analyses of older and recently bottled wines demonstrated the ability of certain wine microbial species to survive and grow in the bottle. Among them, the spoilage yeast Brettanomyces bruxellensis was predominant, necessitating effective methods for removing these microorganisms before bottling. This work reports on various filtering assays. Each technique was evaluated over several years after bottling by microbial analysis and by volatile phenols measurements. The smaller the pore size, the more microbes were eliminated. Elimination of bacteria required a 0.3-mu m filter, but a 1.0-mu m filter was efficient for yeast elimination. In more tightly filtered wines, volatile phenol concentrations were lower than in less tightly filtered wines and in nonfiltered wines.