Yeasts and molds (YM are spore forming microorganism. These spores are resistant to harsh conditions like extreme pH, drought, and extreme temperature. YM is the index of the cleanliness of environmental bioaerosol in different production plants. Failure to comply with the tolerable amount of YM in the production area will result to food spoilage. YM can easily spoil the food due to its wide tolerance to environmental condition. (e.g. water activity of less than 0.85 and as low as 0.45). thus based on Food and Drug Administration’s regulation, it is part of the release parameters for food and beverages, and part of environmental monitoring system through air sampling.