Microbiological - Direct PlatingThere are a number of options offered to grow microbes on Petri plates using selective growth media, which can selectively allow the growth of target microbes; including Saccharomyces yeast, non-Saccharomyces yeast, and bacteria. Once samples are plated, they are incubated for 14 days at 30 C prior, during which time any present microbes grow and multiply. Finally, clusters of growth, also known as colonies, are examined using phase contrast microscopy. Yeast colonies are further characterized in regards to fermentation performance and film production. Bacteria colonies are characterized by Gram stain, and the presence of catalase or oxidase activity. Presumptive identification is made based on these characteristics.
