Sanitation

The following are a few general comments about sanitation. A more detailed presentation on sanitation will be made by Larry Kropf, DiverseyLever, Oakville.. Cheese makers are frequently too relaxed about sanitation because they assume that the active cultures and development of acidity in cheese offer adequate protection against pathogenic organisms. It's true that well made cheese normally offers significant hurdles to most pathogens, however, several pathogens are well known to survive and may grow under the conditions of cheese manufacture and curing (see also Section 4.5). Cheese with minimal acid development such as Latin American White Cheese (Queso Blanco) and cheese which undergo increased pH during curing (Brie, Camembert and, to a lesser extent, Blue) are especially susceptible to growth of pathogens.

1. Culture room

  • separate from plant
  • positive air pressure
  • totally clean at all times
  • restricted access

2. Drains

  • must have traps
  • must be adequate for peak periods to avoid any pooling of whey and/or wash water

3. Surfaces

  • all surfaces clean and sanitizable
  • all food contact surfaces must be stainless
  • exceptions are curing boards and rooms for surface ripened cheese

4. Personnel

  • clean clothes, clean person, especially hands
  • Staphylococcus aureus and fecal coliforms are often from people

5. Plant Environment

  • ideally have positive air pressure
  • separate raw milk operations from rest of the plant
  • no implements or equipment or persons move from raw to pasteurized sections
  • check coliform counts of equipment and employees on regular basis

6. Cleaning Systems Depend on:

(1) Soil to be removed: fat, protein or milk stone

(2) Surface to be cleaned

  • note that stainless steel is not a smooth surface to the eye of the microscope nor to a microorganism
  • from the perspective of a coliform organism, a stainless steel surface is world of mountains and valleys stretching out into infinity
  • mechanical abrasion only further roughens the surface and makes cleaning those valleys more difficult
  • must let the chemistry do its work
  • chlorinated alkaline cleaners will remove both fat and protein if applied for sufficient time
  • check vat surfaces with a fluorescent light; if the surfaces reflect bluish/purple light you know there is a residual protein film

Cleaning Action:

(1) Water rinse: removes loose soil

  • collection of first rinse, especially from milk storage tanks, will substantially reduce biological oxygen demand (BOD) loads in the drain

(2) Chlorinated alkaline detergent with chelator

  • detergent provides wetability
  • chelator softens water and removes milk stone
  • alkali swells and loosens proteins
  • rinsing action is then sufficient to remove soil

(3) Water rinse

(4) Acid rinse: nitric, phosphoric

  • complete removal of milk stone and water hardness

(5) Rinse

(6) Disinfectant