Production of active dry baker's yeast.

Active dry baker's yeast has been prepared by
growing a strain of Saccharomyces cerevisiae
Hansen var. ellipsoideus in a culture medium
of the following composition: molasses, 4;
ammonium sulphate (or urea), 01; and potassium
dihydrogen phosphate, 0.1 per cent. The
crop of yeast obtained after 24 hr. of growth
was centrifuged and then dried in a current of
cool air to a moisture content of 8.0-10.5 per
cent. In trehalose content (10-12 per cent) and
viability (3.5-4 x 1010 cells/g.), the product compares
favourably with imported material and
has shelf-life of 6-7 months.