Don't be to hard on Milwaukee. I am willing to bet that there are other market areas where cleaning practices are insufficient as well. The samples for this audit was actual beer which then was transported to the lab for testing for yeast, mold and bacteria using plate count method. Plate count method is regarding by labs as one of the most accurate methods for this type of testing.
The system used by AB is a surface swabbing method utilized with a handheld electronic
ATP device that measures RLUs (Relative Light Units). The lower the RLU count, the cleaner the surface. These units require training for correct usage and can produce inconsistent readings if used improperly.