Last month, we bought and installed the lab equipment and materials needed to test our raw milk daily following the FDA recommendations for testing foods, specifically dairy products. The materials come from 3M, and I think they are recent technology that lets us get results from two tests in 24 hours. We settled on a test procedure where we produce two sets of test plates each day: one set of plates for the combined deliverable milk (we label it "C") and one set for a single cow's milk which we label with the cow's name. We rotate through the cows on a daily basis, so each cow gets tested once a week.
It has been about a month since we started testing and we have yet to see a plate that gets close to the cfu/ml (colony forming units per milliliter) counts that are allowed for pasteurized milk. Every day, I scan the plates and produce a picture like this one from November 11th:
When milk is heading to pasteurization, it is allowed to have up to 500,000 cfu/ml. After pasteurization, it is allowed to have no more than 20,000 cfu/ml (no more than 15,000 in some States).
To determine the cfu/ml of our raw milk, you would count the dots on the white plate and then multiply the number by 100. So our combined milk test for Nov 11 shows about 1400 cfu/ml. Dori's Single-Moo Milk test shows about 200 cfu/ml. On the pink slide, you can have up to 10 red dots that have an associated air bubble. You don't count air bubbles with no red dots, nor red dots with no air bubble. So the combined test above has 1 cfu/ml. Dori's has none. These results are typical of what we see on a daily basis.
Note that on the white plate above, you would have to count 200 dots to have a cfu/ml of 20,000. After testing our milk for a month now, if we ever saw counts that high, counts that are declared safe for pasteurized milk, we would think something was seriously wrong (test got contaminated, poor cleaning/milking practice, etc.) and implement corrective actions. But the milk would still pass the standards for pasteurized milk. Weird, eh?
As farm share owners, we are on contract with you to take good care of your cows, feed them right, and get your milk to you following a well-designed process that you can review and approve. The Single-Moo milk™ process that we designed delivers very clean milk. We had a pretty good feeling that it would before we got the lab, but we're still excited to see the process validated. Every day, we ensure that our delivered milk exceeds the State and Federal standards for pasteurized milk.
In addition to the lab test, we regularly test the milk from each teat using the California Mastitis Test. Quarters that respond significantly to the CMT are excluded from the deliverable milk and either served up as calf milk or composted. Currently, Cindy is our only cow with mastitis, and one of her quarters responds significantly to the CMT. She has two clean teats, and one that lightly responds so her milk is calf milk. She seems to be on the mend though, so that could change soon and we will see her Lab Tested Single-Moo Milk back in the delivered jars.