Milk doesn’t taste good if the dairy isn’t clean. Worse, milk produced or processed in unclean surroundings can promote disease. The University of New Hampshire Cooperative Extension, in cooperation with the New Hampshire Dairy Goat Association, sponsored a seminar on milk sanitation to present ways to keep raw goats’ milk both tasty and safe. UNH Extension presenters were Dot Perkins, livestock field specialist in food and agriculture, and Catherine Violette, professor and specialist in food and nutrition; they were joined by John Porter, UNH Extension professor emeritus. Producing quality milk requires three things: clean animals, cleanable facilities and equipment, and proper milking procedures and handling.
In the barn
Good milk begins with healthy animals. Good milking practices begin in the barn. Start the milking process by washing very dirty udders with warm soapy water and paper towels. Then dry the udder and apply an iodine pre-dip. Wait for 30 seconds, then use a paper towel to wipe it off. If the udder is relatively clean, pre-dip is adequate. Paper towels should be used instead of rags, which become soiled and can transfer material from one goat to the next. To avoid getting goat hair and attached materials in the milk, Perkins advises clipping the udder and the area under the tail head before kidding. This will make both kidding and milking cleaner.
Clean the milking stall regularly. A steel milking stand is preferable, but a wooden one can be used if it is painted and has a cleanable rubber mat on the platform. If you do not have a cleanable surface on the milking stand, keep the bottom of the milking pail clean by placing it on a white plastic cutting board. A cutting board under the pail will reduce the possibility of contaminated material being transferred from the barn to the kitchen or other milk processing area.
“Keeping supplies such as paper towels, teat dips, cutting board, etc., near the milking stand makes for efficient, safe milk practices,” says Perkins. “You’re more apt to follow safe milk practices if everything is streamlined and convenient.”
Bacteria love milk
At 100.4 degrees Fahrenheit, milk leaving the goat’s udder is the perfect temperature for bacteria to grow. Bacteria can be introduced to the milk through bedding material, via other animals in the barn such as cats, dogs or mice, or by the person doing the milking. While it may be pleasant to milk outdoors with the wind in your hair, remember that any number of contaminants thrive in the outdoor environment.
Clean and suitable equipment
Stainless steel and glass are the best materials for milk buckets. Galvanized buckets contain lead and are thus unsafe for food, and plastic cannot easily be cleaned and sanitized. If you do use plastic, be sure it is food-grade.
If you use milking machines, associated hoses and tubes must be kept clean. Milk transport pipelines, which are used in larger operations, must also be cleaned. “It is difficult to get to all the nooks and crannies in a pipe system,” says Porter. “Flush the system regularly with potable water at a minimum temperature of 125 degrees Fahrenheit. At least once a year, disassemble the system and clean it.” Save energy and money by using an on-demand water heater.
Proper milking procedures
- Prepare equipment and animals.
- Sanitize bottles.
- If necessary, wash the udder with paper towels. To avoid cross-contamination, do not use rags.
- Pre-dip with an iodine product.
- Check for mastitis by pre-milking into a strip cup. Then, after 30 seconds of contact time, wipe off the teat dip. Check the strip cup for the stringy chunks that are evidence of mastitis. “It is important that any goat with mastitis be milked last to avoid contaminating other goats,” says Perkins.
- Use disposable plastic gloves. Do not reuse them, and change gloves between goats. Bear in mind that humans can be the vectors of disease.A covered stainless steel container is useful for cooling and holding milk. Photos by Kathleen Hatt.
In the milking stall:
1. Wash and/or pre-dip the goat’s udder.
2. Observe the foremilk and check for mastitis.
3. Dry the udder or wipe off the pre-dip with a paper towel.
5. Post-dip the teats.
Cool it quickly
The cold chain – the temperature-controlled supply that must remain unbroken throughout the series of storage and distribution activities between the goat and the consumer – begins in the barn. To keep raw milk safe, cooling needs to begin in the barn immediately following milking. The goal is to get milk from 100.4 degrees, the temperature at which it leaves the udder, to 40 degrees or below within two hours after milking. A food-grade stainless steel container works best for cooling quickly.
While you are still in the barn, place the milk in a cold water bath. A big ice-filled cooler works well. Be sure to keep the milk inside covered. A cold water bath works better and faster than a refrigerator, as Violette confirmed when she experimented with cooling rates. She found that a quart of milk in a stainless steel container placed in an ice water bath could be cooled to 40 degrees in seven minutes, but it took five and a half hours to achieve the same result with a glass quart jar in the refrigerator.
After cooling, milk should be held in a refrigerator at 40 degrees or below. Use a thermometer to check temperatures and be sure it is accurately calibrated. Perkins says, “Be sure your customers have a cooler in their car when they come to pick up milk. You don’t want to be the one responsible for contaminated milk.”
“Food safety is all about managing risk,” says Violette. Risks include biological agents (bacteria, viruses, parasites, fungi, biological toxins), chemicals (cleaners, sanitizers, polishes, lubricants, pesticides), and physical hazards (metal shavings, wood, fingernails, glass, jewelry, bandages, staples). Foodborne hazards can cause illness and injury or even death, and foodborne illnesses are not uncommon. Every year in the U.S., one in six Americans gets one. Listeria, salmonella, E. coli O157:H7 and campylobacter are some of the more common causes of foodborne illnesses.
A milking stall’s walls are easier to clean if they are painted or stainless steel, not raw lumber. Photos by Kathleen Hatt.
From barn to kitchen
You can be a source of milk contaminants. Your barn clothes should be changed or covered before you begin handling milk. Overalls (worn in the barn and removed before processing milk) or a disposable apron (available from restaurant supply stores and added in the processing area) works well. Hair should be restrained in a cap or net. Do not handle raw milk, equipment or containers if you have a communicable disease such as a cold, flu, diarrhea, vomiting or hepatitis A.
Be sure to wash hands in warm soapy water before you step into the processing area and as often as needed thereafter. Effective hand washing includes wetting hands with warm water, applying soap, rubbing hands and arms a minimum of 10 seconds, cleaning under nails and between fingers, rinsing thoroughly, and drying with a paper towel.
Pay attention to personal hygiene and equipment and observe safe handling practices throughout cooling, pasteurizing, bottling, storing, labeling and selling. Be sure to keep accurate daily records so that any problems can be traced and corrected.
“Gloves can be good and bad. Don’t fool yourself into thinking you’re OK just because you’re using gloves,” says Porter. “The purpose of gloves is to protect the product, not the person.” Effective glove use begins with thorough hand washing before gloves are put on. Whenever gloves become dirty or torn, they should be changed. They should also be changed after touching yourself (even after removing a stray hair from your forehead or scratching your nose), after touching another surface or food, and after four hours of continual use. Do not wash or reuse disposable gloves.
Cleaning and sanitizing equipment
To minimize the risk of contaminating equipment used to contain and process milk, always use containers and equipment approved for contact with food. Approved containers include glass and stainless steel and certain FDA or NSF International-approved nontoxic materials. Containers, equipment and surfaces all need to be both cleaned to remove soil or food and sanitized to decrease microorganisms to safe levels. Always use potable water, paper towels and single-use filters. An Environmental Protection Agency-registered sanitizer, such as chlorine or other approved dairy cleaner, should be mixed daily in a dedicated sanitizing solution container. To sanitize milk containers, equipment and surfaces effectively, Violette recommends:
1. Rinsing with warm water (100 to 110 degrees) to remove soil or food.
2. Washing with hot water (125 to 165 degrees) and a detergent specifically for use with dairy products (usually a chlorinated alkaline solution).
3. Rinsing with an acidic solution to neutralize alkali residue.
4. Sanitizing prior to next use with an acid sanitizer. The same sanitizer can be used for steps 3 and 4. Bottles should be washed, rinsed, sanitized and drained no more than four hours prior to filling. While consumer-returned bottles are exempt from washing, it is not wise to refill visibly dirty bottles.
As soon as milk is bottled, label it. Be sure to check your state’s labeling requirements for raw goats’ milk, as they vary from state to state. In New Hampshire, bottle labels must include this information:
- Raw Goats’ Milk
- Name and address (including zip code) of producer
- Net amount of contents
- The “sell by” date, which should be no more than five days from bottling
Farms selling raw milk at the farm where it is bottled must display a conspicuous sign saying: “Raw milk is not pasteurized. Pasteurization destroys organisms that may be harmful to human health.”
As various antibiotics used to treat goats may persist in their milk for certain periods, Porter advises adding to the label a further statement: “This milk has not been tested for antibiotic residue.” Perkins says, “You and your vet need to be aware of and to follow the labeled withholding times for different medicines. Penicillin, for instance, will remain in milk for as long as 30 days following treatment.”
Whether your goats’ milk is for in-home use or retail sale, keep it healthy and safe by cooling milk quickly and keeping it cold; keeping the kitchen, utensils and equipment clean; and observing best personal hygiene practices.