This International Standard specifies a horizontal method for the enumeration of microorganisms, by counting the colonies growing in a solid medium after aerobic incubation at 30 °C. Subject to the limitations discussed in the introduction, this International Standard is applicable to products intended for human consumption or the feeding of animals. The applicability of this International Standard to the examination of certain fermented food and animal feeding stuffs is limited. For the examination of fermented food and animal feeding stuffs, other media and/or incubation conditions might be more appropriate.