Wort Agar is a general purpose mycological medium, equivalent to the medium described by Parfitt¹ and especially suitable for the cultivation and enumeration of yeasts. The medium, which duplicates the composition of natural wort, is of an acidity which is optimal for many yeasts but inhibitory to most bacteria. Parfitt investigated the relative merits of wort agar and other media for the count of yeasts and molds in butter, and recommended the use of dehydrated whey, malt or wort agar for the purpose. Scarr² employed a modified wort agar (’osmophilic agar’) for the examination of sugar products for osmophilic yeasts. Scarr’s technique is also used for the determination of osmophilic yeasts occurring in materials used in the manufacture of soft drinks.