Various direct approaches have been developed for enumerating microbes in
wine. The technique employed most often is simple microscopy from which winemakers
can readily differentiate yeast from bacteria, as well as determine microbial
concentrations directly in wine with the use of counting chambers (Amerine and
Kunkee 1968). Microscopic analysis, combined with use of simple stains such as
methylene blue (Borzani and Vairo 1958), enables colorimetric differentiation of
live versus dead yeast cells.