Cleanliness vs. sterility: two aims, not steps

The standard

Workable cleanliness measures hygiene by controllability, not by freedom from germs: enough cleanliness that no unwanted population takes hold, little enough intervention that the wanted flora remains.

Criteria

• Cleaning removes nutrient films before they are colonised
• Sterility stays confined to the points that strictly require it
• The measure is the controlled population, not a germ count of zero
• Wanted microorganisms are not removed along with the unwanted

Distinction

Cleanliness ≠ sterility: cleanliness limits microorganisms, sterility eliminates them entirely. Sterility ≠ wine quality: a germ-free setting says nothing about the wine, only about the intervention. Workable cleanliness ends where control would wipe out the wanted flora.