Cleaning and Sanitizing Milk Handling Equipment

Published on Mon, 05/18/2015 - 9:05am

When developing methods for the cleaning and sanitizing of dairy farm milk handling equipment, the primary concern is that procedures are designed to remove the various soils that form on equipment surfaces. Such soils, unless they are completely removed, provide a nutrient source and a breeding ground for bacteria that subsequently can contaminate milk and dairy products.

Because the removal of soils is the fundamental purpose of cleaning, an understanding of the types of soil that may be encountered is essential to a successful cleaning program. There are two basic categories of soils associated with the cleaning of farm milk handling equipment. These are (1) organic soils, and (2) mineral soils. The characteristics and sources of these are worthy of individual consideration.

1. Organic Soils. These include the fats, proteins and sugars that comprise the major constituents of milk. They are very complex soils, and the tenacity with which they adhere to contact surfaces varies according to such factors as the age and dryness of the soil, and the extent of heating and length of heating to which milk has been subjected. Because of these factors, it is imperative that organic soils be removed from surfaces as quickly as possible. Unless this is accomplished there is a tendency for such soils to set or harden as they dry, thereby forming a tenacious deposit that is difficult to remove. It is for this reason that virtually all cleaning procedures stress the point that cleaning should begin immediately after equipment and utensils have been used.

2. Mineral Soils. Mineral soils are not as obvious as the organic soils derived from milk. These soils result from the precipitation to surfaces by certain inorganic salts such as calcium, magnesium and iron salts which are responsible for contributing “hardness” to water. In addition, mineral precipitation may be enhanced by cleaning agents themselves if such agents are not compatible to water hardness conditions or if cleaning agents are indiscriminately used in amounts or at temperatures which are contrary to the cleaner manufacturer’s directions.

When minerals precipitate onto a surface, they entrap some of the organic milk constituents within the crystalline film, and as this process is repeated over a period of time, a milkstone deposit eventually becomes apparent. Milkstone harbors bacteria, and when moisture is present, an excellent medium is provided for bacterial growth. Because mineral deposition is so directly related to water hardness conditions and its compatibility with cleaning materials, it is necessary that an analysis of the mineral characteristics of the water supply used, such as hardness, iron, sulfur, etc., be made in order to be able to select cleaning compounds that will be compatible to the water supply available. This point cannot be overemphasized and is fundamental to an adequate cleaning program. The prevention of mineral deposits on equipment surfaces is a major factor in good cleaning.

This is an excerpt from the Dairy Practices Council’s Guideline #9, Cleaning and Sanitizing Farm Milk Handling Equipment. More information can be found at the Dairy Practices Council’s website:http://www.dairypc.org.