For the homesteader or farmer operating a small cow share program, buying a commercial milk cooler (to bring the temperature of their milk down quickly) is not practical for most. This is true not only due to cost, but also because of a lower volume of milk than necessary to operate the chiller.
Some family cow owners submerge their milk in coolers filled with ice. Others will put their milk in a freezer for a while in order to chill it more quickly. Once it's chilled, they transfer it to the refrigerator. Both of these methods work great but when I was operating a cow share program, my volume of milk was high enough that I needed something a little more efficient. In addition, I was frequently putting my glass milk jars in the freezer, forgetting about them, and coming back to find frozen milk and busted jars. One day as I was contemplating the best way to tackle the problem of chilling milk without having to go back and remove jars from the freezer after several hours, it came to me that I might be able to use my cheese cave in reverse.
|A typical bulk milk cooler. Photo courtesy of Aviva.|
Back in 2010, I share with our readers how that I bought an external, overriding thermostat from through a brewing company, and installed it on an old freezer so that I could manually adjust the temperature for aging hard cheese. (You can read that blog post at this link.) It occurred to me that I could turn the manual thermostat back to just above freezing and leave my milk to chill, thus eliminating the urgent need to monitor and remove the glass jars of milk from the freezer before they burst as I had been doing previously. This method worked perfectly for me for a number of years as I ran the share program, and proved to be a simple and economical solution.
|External Override Thermostat. Purchase Info Here.|
Fresh cow's milk freezes at approximately 30 - 31 degrees Fahrenheit. However, the freezing point of milk varies slightly depending on the breed of cow, quality of the milk, time of day and season of the year, type of forage/feed the cow is eating, etc. Fresh milk is approximately 99 - 102 degrees when it leaves the cow's body. The temperature of the milk should be decreased to 40 degrees within an hour of milking as bacteria count doubles every 20 minutes at body temperature. Chilling your fresh milk quickly increases the shelf life of the milk and creates the perfect situation for you to experience the sweet taste of farm, fresh, raw milk.