The traditional practice of using wood boards for cheese aging must meet the contemporary practice of sanitation to ensure food safety.
The use of wood boards for aging is a longstanding tradition in cheese manufacture. The properties of wood that are beneficial for cheese aging can also pose food safety hazards, namely its porosity and tendency to develop biofilms.
The porosity of wood provides a natural wicking effect that helps to dry and age cheese. The wood pores serve as sites for bacteria to congregate, grow and develop biofilms. This can be beneficial when populations of desirable organisms grow and promote the development of positive attributes to the cheese rind and flavor. However, this is also an opportunity and ideal conditions for pathogens to grow. Some research studies have shown that populations of desirable bacteria may out-compete and inhibit the growth of pathogens. But the risk of pathogen survival in the wood is a serious concern and must be addressed by good sanitation practices.
Practices for Using Wood Aging Boards
Good practices for using wood aging boards in cheese manufacture are:
- use boards that are safe for food contact
- check to make sure any wood preservative used are food grade
- use boards that are of sound construction, in good condition, and free from surface defects
- make sure boards can be easily removed from their support system for cleaning and inspection
- inspect boards regularly for damage
- replace boards when they are compromised
- maintain proper monitoring procedures for environmental bacteria
- keep corrective action plans updated in case of unwanted contamination
SSOPs for Wood Aging Boards
Facilities that use wood boards for aging cheese should have a Sanitation Standard Operating Procedure (SSOP) in place to ensure that proper cleaning and sanitation procedures are written, followed and documented. Key elements to include in an SSOP for wood boards are:
- frequency of inspection
- cleaning and sanitizing procedures
- frequency of validation that cleaning procedures are adequate
- example: swab testing of clean board surfaces for presence of bacteria
- frequency of cleaning
- identify the records used for monitoring
- corrective actions in case of contamination
Cleaning and Sanitizing Procedures for Wood Aging Boards
Wood boards should be cleaned and dried in the same building as the aging room to avoid outside contamination. Wood boards should not come in contact with the floor or other unsanitary surfaces at any time.
The minimum, suggested cleaning conditions are:
- Wash and scrub boards with 140°F soapy water.
- Rinse boards with 140°F water.
- Sanitize boards with either a 200 ppm chlorine solution or a 10% hydrogen peroxide solution. Do not rinse off the sanitizing solution.
- Dry boards thoroughly using air or in a drying kiln. Air-dried boards should be placed on metal shelves with sufficient space between the boards for proper air flow.
- Store clean, dry boards in a sanitary manner until next use.
- Fill out cleaning and sanitizing records.
The author thanks Marianne Smukowski from the Wisconsin Center for Dairy Research for her input on cleaning and sanitizing procedures.