Yeast Flora of Cider Factories

SUMMARY Harvested and stored fruit, and juice collected from the cider press, showed larger numbers and a wider range of yeast species than did fruit picked aseptically from the tree. The ratios of species changed during storage. Under clean factory conditions or in the pilot plant the range of species was limited. Saccharomyces spp. and other spore‐formers were absent, possibly having been eliminated by thorough cleaning of equipment. Kloeckera spp. which increased markedly on the fruit during harvesting and storage, remained as an appreciable component of the juice microflora. Factories with less rigid standards of sanitation harboured a much wider range of yeasts. Saccharomyces spp. and extraneous sporeformers, which were rarely detected on the whole fruit, appeared in the freshly pressed juice, and together with Kloeckera spp., made up a large proportion of the microflora. The undesirable sporeforming spp., Saccharomycodes and Hansenula , were detected in some instances.