Abstract: A method and system of preparing a sample for microbial testing by providing a sample in a sample bag, a dry sterile growth medium in a bag, and a source of pure (Type II) water heated to a temperature of about 25-50° C., homogenizing the sample, reconstituting the dry medium with the heated Type II water, mixing the medium and sample to a homogenous consistency and incubating the sample for a period of time sufficient to allow the growth of microbes. A tankless water heater or a heat exchanger can be used to heat the water to a desired temperature. The Type II water can be heated either before or after it is made. A blender can be used for the sample homogenization as well as the final mixing before incubation and may be a paddle or stationary blender. Microbes are detected by various methods well known in the art.