4 Tips for Filtering, Chilling and Cleaning Up To Ensure Clean and Safe Milk

Reader Contribution by Nick Zigelbaum
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In my previous posts on making clean milk I covered the definition of clean, how to find a healthy cow, how to set up a clean milk parlor and how to milk. Now I will discuss filtering, chilling and cleaning up.

1. Filter With the Quickness

After milking, I release my cows from the parlor and take the milk to my milk room. This room is a lot like a kitchen, kept clean and free of any animals. In our barn the milk parlor is downstairs and the milk room is upstairs. In here I filter my milk with a stainless milk strainer into a separate stainless milk can (for making yogurt or cheese) or directly into half-gallon jars (for sippin’ milk). It’s important to filter relatively quickly after milking to get any hair, dirt or manure out of the milk before it can cause widespread contamination. It will also improve the flavor and keeping quality of your milk to filter quickly. Longer filter time will directly correlate to total bacteria count. Machine milkers get the convenient benefit of an in-line filter either in the bucket or in a pipeline. This is an excellent way to filter very fast and without much trouble.

For hand-milkers who don’t have the space for a separate milk room, your kitchen sink will do. Just make sure your filter, sponge, and milk containers are only used for milk handling and always kept clean. Using them for anything else will invite contamination.

2. Chill Out: Cool Milk Down to 40 Degrees Fahrenheit

Best least-cost practice for hand milkers is to place cans or jars of milk into an ice-water slurry to cool down to 40°F in under two hours. Simply placing warm jars into a refrigerator will not cool milk fast enough. E. coli proliferates in pasteurized and raw milk that reaches temperatures above 40°F during transportation and handling. The same may be true for homestead dairies. Try not to submerge the jar as water can get into the lid before it seals. The best high-tech option is to use a bulk tank (seen below) to maintain low temperatures. Bulk tanks agitate the milk which cools milk very fast, mixes the fat and skim layers which prevents bacterial growth and ultimately extends shelf-life and lowers bacteria counts. Shelf-life can be extended by 100 percent with a bulk tank.

Alternatively, a useful low-tech solution utilizes the cooling effects of a running stream. Place your warm milk jars into a milk crate and lower into a creek. Again, keeping the jar lid above the water line. This method will cool milk fast and can be a year-round solution for cooling and keeping cold milk. An ever more convenient approach would be to siphon water from a high point in your creek to a tub or sink near or even inside the milk room. Let the siphoned water run over continuously and place your jars in that. Hydrocool!

3. Time to Clean Up

Washing the equipment used to handle milk is the most important step to keep the milk clean. In your milk room you will want to have a big sink to clean all those large stainless cans and containers. First perform a cold or lukewarm water rinse on milking equipment. Using hot water right away will burn milk onto your equipment and become a source of contamination. After rinsing, soap it all up and rinse again with as hot water as you can handle. Biodegradable dish soap is sufficient for cleaning jars and pails. Cleaning up takes a little longer for machine milkers, who will need to run their machines with cleaning solution for 10 minutes and once per week break down their claw and bucket and clean completely for 30-45 minutes. Once all the equipment is clean, place everything on a clean, dust-free rack to dry. Leave jars and cans open and upside down. Next time you milk, everything should be dry and have no smell to it at all.


You’ll notice if a customer returns a clean jar with the lid tightly screwed on that the inside of the jar smells foul. A jar like that will have to be re-washed. I always leave lids off; air-flow and sunshine are the best disinfectants out there.

4. Consider Testing Your Milk at a Local Dairy Laboratory

After you are up and running with your milk routine, consider sending samples out for testing on a regular basis as a way to double-check your milk. Cheesemaker’s send samples every week to make sure of the quality of their inputs as they make cheese. Vermont Tier II producers are required to test twice per month. I test a couple weeks after my cows freshen in the spring, again if I suspect any mastitis or change my routine during the season and once more to check if they’re bred in the late summer/fall. It’s a good idea to test for Johne’s and Leukosis once per year, which can be done while checking for pregnancy with our Annual Wellness Test.

To recap, I recommend testing an animal’s health before joining the herd, creating a clean milking parlor and being diligent in the filtering, cooling and cleaning of your milking equipment. Following these steps will help you fear not the pathogens and bacteria, but rather to make cheese or yogurt with confidence and relish in the metamorphosis of sunlight and grass into a glass of clean, delicious raw milk.

Here’s a little bit more about the Bob-White Systems Dairy Lab. The Lab provides a range of testing services to the region’s dairy (cow, sheep, and goat) farmers, raw milk producers, cheese makers and other dairy-food processors. It is the only private, FDA certified milk testing facility in Vermont that primarily serves these producers. The lab works closely with customers to provide individual service that is expedient, accurate and useful. Our laboratory staff own and milk cows and goats thus we can relate to our customers. We are happy to go over the test results and discuss ways to improve practices in order to reduce pathogens and contaminants found in products.

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