Appendix H: Use of wood in dairy facilities

Introduction

Wood is an absorbent surface that is difficult to clean to keep free of contaminating bacteria. In dairy facilities, wood is not a suitable material for food contact surfaces, supplementary utensils or physical structures where product is exposed or placed at risk of contamination, with a few exceptions:

• Wood used for “640” cheese boxes (with appropriate liners and pallets)
• Wood used for shelving in cheese curing rooms for bacterial surface ripened cheeses

Definitions

For the purpose of this document, the following definition applies.

Bacterial surface ripened cheese: a cheese whose rind is formed by bacterial action (for example, Saint Paulin, Bel Pase and Tilsit).

Wood shelving used for cheese curing

For reasons of tradition and suitability, wood is used to aid the surface ripening of cheeses.  The bacteria (usually Brevibacterium linens) on the shelf surface break down part of the cheese protein and form the rind.  The cheeses are washed and turned regularly during ripening.  The cheese shelves are seeded with the bacteria which become ingrained in the wood.  Under controlled conditions, the harmless bacteria significantly outnumber the undesirable microorganisms and therefore the risk of contamination is minimized.

Conditions

• Ensure the wood that is used for cheese shelves to cure bacterial surface ripened cheeses is smooth and either unsealed or sealed with a suitable sealant.
  • Supports for the shelves should be stainless steel or a non-corrosive, non-absorbent material.
• Have a written, effective program to clean and maintain the shelves. 
  • The program specifies:
    • the frequency and methods of washing;
    • checking and replacing for physical condition (splinters, cracks, mite infestation);
    • and if required, environmental sample monitoring of the product contact surfaces and the room environment.
  • Keep applicable records.
• Verify that there is no scientific evidence indicating that the use of wood shelves used to cure bacterial surface ripened cheeses poses a biological risk to the cheese.