Cereal Chem. 70:219-225   |  VIEW ARTICLE

Baker's Yeast Sampling and Frozen Dough Stability.

P. Gelinas, M. Lagimoniere, and C. Dubord. Copyright 1993 by the American Association of Cereal Chemists, Inc. 

The cryotolerance of six commercial baker's yeast strains grown under identical incremental feeding (fed- batch) conditions was evaluated in frozen doughs. Slight differences in survival were observed between yeast strains subjected to rapid freezing rates (about 10 C/min). All strains showed similar cryotolerance at slow freezing rates (about 1 C/min) followed by storage for 12 weeks. As part of a collaborative study between two laboratories, 21 commercial baker's yeast samples from seven trademarks (from which most strains were screened) were compared on the basis of their cryotolerance in frozen doughs. A rapid freezing test (measuring gas production) and three-month storage tests (measuring gas production, dough proofing time, and bread specific volume) showed that yeast cell cryotolerance varied greatly among the commercial yeast samples used to prepare frozen doughs. Because of the great variability in cryotolerance among yeast samples, none of the seven yeast trademarks tested from Canada, France, and the United States was superior to the others. These results show that the major effect on frozen dough stability is the commercial baker's yeast sampling rather than strain or trademark, and they stress the importance of quality control for cryotolerance of the baker's yeast samples used in frozen dough production.