Appendix 8.  

The following methods and procedures will provide steam of culinary quality for use in the processing of milk, milk products and whey.

Potable water or water supplies acceptable to the regulatory agency shall be used.

Feed waters may be treated, if necessary, for proper boiler care and operation. Boiler feed water treatment and control shall be under the supervision of trained personnel or a firm specializing in industrial water conditioning. Such personnel shall be informed that the steam is to be used for culinary purposes. Pretreatment of feed waters for boilers or steam generating systems to reduce water hardness, before entering the boiler or steam generator by ion exchange or other acceptable procedures, is preferable to addition of conditioning compounds to boiler waters. Only compounds complying with Section 173.310 of Title 21 of the Code of Federal Regulations may be used to prevent corrosion and scale in boilers or to facilitate sludge removal.

Greater amounts shall not be used of the boiler water treatment compounds than the minimum necessary for controlling boiler scale or other boiler water treatment purposes. No greater amount of steam shall be used for the treatment and/or pasteurization of milk, milk products and whey than necessary.

It should be noted that tannin, which is also frequently added to boiler water to facilitate sludge removal during boiler blow-down has been reported to give rise to odor problems, and should be used with caution.

Boiler compounds containing cyclohexylamine, morpholine, octadecylamine, diethylaminoethanol, trisodium nitrilotriacetate, and hydrazine shall not be permitted for use in steam in contact with milk, milk products and whey.

A supply of clean, dry saturated steam is necessary for proper equipment operation; boilers and steam generation equipment shall be operated in such a manner as to prevent foaming, priming, carryover and excessive entrainment of boiler water into the steam. Carryover of boiler water additives can result in the production of off-flavors. Manufacturers' instructions regarding recommended water level and blow-down should be consulted and rigorously followed. The blow-down of the boiler should be carefully watched, so that an over-concentration of the boiler water solids and foaming is avoided. It is recommended that periodic analyses be made of condensate samples. Such samples should be taken from the line between the final steam separating equipment and the point of the introduction of steam into the product.

Suggested piping assemblies for steam infusion or injection are shown on Figure 5.

Other assemblies which will assure a clean dry saturated steam are acceptable.