milk: when it doesn't taste right
Farmers from TN wrote with a question about changes in their cow's milk, the came up with the answer themselves:
Our cows are doing great, but our milk has suddenly changed. Our milk has tasted unpleasant for a couple days. Today I went to skim the cream from yesterday's milk, but there was no cream line. The whole jar was a consistent white (instead of a marked separation between milk and cream) and looked thicker than usual. There were no clumps when I strained the milk.
How soon before calving does milk change to colostrum and what are the signs? She's supposed to be due to calve in March. I know that human colostrum is yellow, and our milk is still white, so we may have something else going on?
Our cow is on new pasture on a different part of our farm from where she was previously rotating. We are also supplementing with hay since we didn't have the cow in time to stockpile pasture. I've heard that milk can change based on what she's eating, so that may also be a possibility?
Do you have any suggestions or troubleshooting tips for me?
-- brief request for more information from the Doughertys:
Hmmmm, well, no cream line and no clumping sounds like colostrum. Does the milk taste salty (mastitis) or bitter (colostrum or forages)?
They can switch to colostrum several weeks ahead of time, but six weeks sound like a long time.
Yes, forages can make milk taste different, but the lack of separation doesn't sound like a forage issue
I look forward to hearing the details!
The unpleasant milk was tasting sour and smelled a bit like buttermilk. I've noticed that even the milk I thought was fine only lasts about half a day. The milk that sits in the fridge any longer than that starts to ferment. I've been thinking through our processes in the kitchen. I strain our milk with reusable cheese cloth. Since it's been so cold and wet, I haven't been hanging my cheese cloth on the clothesline. I'm wondering if my cheese cloth is contaminated and effecting my milk? I have them all in a pot of boiling water right now. Maybe that will fix our problem?
Okay, you're absolutely right that the short time before fermentation is a great clue to what is going on. If the milk isn't sitting around warm for a long time, then there must be some source of bacteria at work -- something that is inoculating the milk with extra bacteria that are shortening the natural fermentation time. I'm with you, the muslin seems like the most likely source. If you were using a milking machine, that would be my other guess, but if you are hand-milking, that's off the table. And I take it for granted that your buckets and other equipment are clean -- they don't need to be sterile, just ordinary clean.
Without sunlight to do your purifying, boiling the straining cloth is a good second; it will cook some proteins onto the cloth, so you may find you have to get a new filter a bit more often, but muslin is cheap and the old rags can be used for something else.
Blessings!