Raw Milk Safety Tests for Quality Dairy Products

The dairy industry is generally producing retail products for human consumption.  Harmful bacteria could cause fatal illness, devastating financial loss, and loss of trust in the u.s. food system. The best way to ensure a clean product is through raw milk safety tests.

What Raw Milk Safety Tests Should Be Done?

Depending on whether or not raw milk is produced for human consumption, there are different tests used by dairy farmers to ensure a clean product. Additionally, each state has different regulatory requirements for testing fresh milk. 

Bacterial Tests

The first test counts somatic cells in the fluid milk.  Milk contains white blood cells along with milk-producing cells. During a cow’s normal lactation, these cells are shed in the milk, and can be counted as a reference for estimating udder health and quality of the milk. A high standard plate count ( with bacterial counts ) may indicate mammary infection or improper sanitation and milk-handling procedures, and further testing is required.

Pathogen Tests

 A tanker sample can be taken by the dairy, collected into a sterile container, and sent to labs to check for growth. Milk is cultured for bacterial and mycoplasma growth to determine the next steps. Salmonella, e. coli 0157, and coliform test are among the most routine pathogen tests for milk. 

What is the Most Common Pathogen Found in Raw Milk

According to the Center for Disease Control, the most widespread illnesses were caused by campylobacter, shiga toxin-producing E. coli, or salmonella from 2013-2018 in U.S. Food.

It’s important to note that all of these disease-causing germs may be totally avoided from ingestion by either safe handling procedures, or pasteurization.

All pathogens can usually be avoided with safe handling practices and pasteurization wouldn’t be necessary. 

Often times, bacterial growth in cultures comes from milk contamination, not from the cow.

 In these cases, proper Pre-milking sanitation procedures, and post-milking equipment handling need to be reviewed. This is where perfection matters when dealing with raw milk.

Does Raw Milk Contain Parasites

Milk can contain parasites such as Cryptosporidium or giardia. Cases of human infection of parasites through milk consumption are rarely documented as they’re extremely uncommon. Food testing through state regulation helps prevent parasitic infection through raw milk.

What Are the Most Common Tests for Determining Milk Quality?

The following tests are the most common used by on-farm labs: somatic cell count, coliform count, and antibiotic residues testing.

The home dairy may not have access to such test kits.  However, sending milk to labs is simple, quick, and low cost.  Test results are sent immediately to the you, the milk producer, for a better idea of milk safety.

Should I Test My Family Milk Cow’s Raw Milk?

I highly recommend using your senses first.  Experience goes far with knowing when and how to test.  

• Does your milk smell or taste off?
• Is the shelf life not as long as you’d like?
• Do you see any kind of solid pieces in your milk filter?
• Does your cow have a swollen, hard, or red udder?
• Does she seem to experience pain when you touch her udder or teats?
• Does she have a history of mastitis?

The answers to these questions will help you determine whether or not a pathogen test with a regulatory lab is needed.

What should I do first?

If your milk tastes off or doesn’t seem to have lasting freshness, you can use a Dr. Naylor’s card to test the pH of the milk. This isn’t a definitive test, but it’s an easy first step. Basically, if the milk turns the yellow dot green or blue, then the milk’s pH isn’t right. There are a few reasons this could happen, but mastitis in your cow will always change the color spot.

Next, you can do an easy California Mastitis Test (CMT) at home. You milk a little from each quarter into the divided receptacles, add a specific solution that comes with the test, and swirl the paddle in a circular motion. If the milk changes to a thicker consistency, it’ll stick to the paddle some and become gel like. This is absolutely a case of mastitis, and you should send samples to your lab for cultures so that you can appropriately treat your cow.

Transparency

If you are providing raw milk products for buyers, testing provides transparency for your buyers. As a small home dairy operation, you want to be sure that you provide clean milk for your own family, but also for those purchasing your raw milk products. For those reasons, I recommend that you err on the side of caution.

If you are uncomfortable with any answers to the above questions, send milk samples to your state lab for cultures. If you have a positive result, work with your local large animal veterinarian for proper drug administration and then withdrawal periods. You can also use a milk testing lab for the presence of antibiotics before continuing consuming or sales of your dairy.

Is Lab Tested Raw Milk Safe?

If lab tested milk results in no culture growth, then it should be safe.  That said, you should continue to take all precautions of sanitizing milk equipment before and after milking. Machines, containers, filters, and hoses should all be properly cleaned and stored for optimal aseptic conditions.

How Many People Per Year Get Sick From Raw Milk?

Raw milk contains several positive elements that make it inherently safe. They kill pathogens in the milk, prevent the intestines from absorbing disease-causing germs, and strengthen the immune system. According to this article, the percentage of those who become sick from pasteurized milk is higher than those who consume raw milk.

Who is at Greatest Risk of Getting Sick From Drinking Raw Milk?

Consumers of or home-milkers who are not following clean sanitation protocols are at the greatest risk of getting sick. Additionally, those with compromised immune systems, the elderly, infants, and pregnant women should take safety concerns seriously.

What is the Most Common Pathogen Found in Raw Milk?

The most common pathogens found in raw milk are strains of staphylococcus or streptococcus bacteria. These are usually due to harmful germs entering the teat canals of the udders while the cow is laying down. Quality testing for high somatic cell counts will determine the presence of bacteria.

Additional Tests and Cleaning Procedures

It is common practice to use antiseptic, food safe cleaners to wash the udder before milking. Teats should be stripped before collecting usable milk, and a post milking dip should be used.

What Else Can You Do to Verify Raw Milk Safety?

Be sure that your unpasteurized milk is sourced from a farm with sanitary conditions. It’s helpful to be able to visit the farm and meet the farmer. Local farmers markets are usually a good place to meet farmers too, and you can rest assured that a state inspector has probably paid them a visit. Ask what kind of quality control measures and raw milk testing the farm completes to be sure its producing safe food items. 

Raw Milk Safety

Raw milk consumption has increased over the last 20 years, yet food-borne illness due to unpasteurized milk has had a decline in the same period of time. Microbiological tests have helped dairy producers in the United States provide good quality dairy products.

You should take care to make sure your don’t leave your milk out of the refrigerator for a long time so that it comes to room temperature. The initial bacterial population will jump with a temperature increase, and that will degrade the quality of milk.

What Temp Kills Good Bacteria in Raw Milk?

Most bacteria will be killed at 180 degrees Fahrenheit. Good bacteria that balances out bad bacteria is killed as well during this pasteurization process. Additionally, all of the quality enzymes and bioactive components in the milk are broken down to become inactive, and you are left without the benefits of consuming raw milk.

Does Raw Milk Ever Go Bad?

Raw milk changes differently than your regular, pasteurized grocery store milk. It cultures and clabbers so that it can be used in certain cheeses and baking. The shelf life is determined by temperature control and bacterial count in the milk.

Raw milk cheeses should be aged for best results. Microbiological testing can be done on them but isn’t usually necessary after six weeks. At this time, positive samples would be easily seen with the naked eye. High counts of coliform bacteria in particular would appear. The influence of raw milk quality determines the safety of cheeses or other raw foods like ice cream and butter.

Does Boiling Raw Milk Make It Safe?

Again, raw milk is inherently safe. Boiling it exceeds the pasteurization temperature and threatens to scald the milk to an undesirable flavor.

How Long is Raw Milk Drinkable?

Raw milk drinkability varies with the source. Often times, our family uses milk up to two weeks after it was produced. Fast chilling after collection, a clean operation, and low presence of bacteria in the cow’s milk will provide you with a longer shelf life.

It’s Not as Scary as it Sounds

According to the National Institute of Health, there were more than three times more deaths due to pasteurized milk food-borne illness than unpasteurized dairy outbreaks during a recent 17 year period.

If you’re seeking out a clean source for raw milk, you can check http://rawmilk.com to find a farm near you.

Let me tell you though, nothing beats producing your own fresh, raw dairy on your own homestead. You have control of your cow, her environment, and cleanliness with an amazing whole food fresh on tap.

Sources:

Raw Milk Safety

“Milk Somatic Cells, Factors Influencing Their Release, Future Prospects, and Practical Utility in Dairy Animals: An Overview.” National Library of Medicine, 2 May 2018, www.ncbi.nlm.nih.gov/pmc/articles/PMC5993762/#:~:text=Milk%20somatic%20cells%20(SCs)%20are,quality%20of%20dairy%20animals%20worldwide. Accessed 19 Oct. 2023.

https://hambydairysupply.com/mastitis-indicator-paper-30-pack-dr-naylor/

“Raw Milk Questions and Answers.” Center for Disease Control, 24 Mar. 2023, www.cdc.gov/foodsafety/rawmilk/raw-milk-questions-and-answers.html#:~:text=Most%20of%20the%20outbreaks%20were,local%2C%20or%20territorial%20health%20departments. Accessed 19 Oct. 2023.

“Raw Milk Is Not a High-Risk Food.” Farm and Ranch Freedom Alliance, 30 Jan. 2013, farmandranchfreedom.org/raw-milk-is-not-high-risk-food/#:~:text=So%2C%20out%20of%209%2B%20million,a%20period%20of%2011%20years. Accessed 19 Oct. 2023.

“Raw Milk Safety.” A Campaign for Real Milk, 15 Apr. 2021, www.realmilk.com/safety/. Accessed 19 Oct. 2023.

“Routine Tests.” Microbial Research Inc., 31 Dec. 2021, microbialresearch.com/raw-milk-testing/. Accessed 19 Oct. 2023.