How To Pasteurize Raw Milk At Home
By Amy Manning
My Suburban Homestead
[Editorial Note: Because microwaves heat unevenly, their use is not recommended to destroy harmful pathogens in raw milk]
I was asked recently how I go about pasteurizing my milk at home. I was hoping that my goats would have kidded by now, so that I could show you in pictures how I pasteurize my milk. But, they have not kidded yet, so here is a quick rundown of the ways you can pasteurize your milk at home.
Pasteurizing milk is a simple concept: the recommendation is to heat milk to 161 degrees for 15 seconds (please note that this is far gentler than grocery store pasteurized milk, which is heated to nearly 300 degrees!) or to 145 degrees for 30 minutes.
I find that the temperature 161 degrees for 15 seconds far simpler than the other method, so that is what I will focus on.
The most important aspect for you to remember when heating your milk is that it is extremely easy to scorch the bottom of a pot or otherwise overheat your milk which causes the milk to curdle or to boil over.
Stovetop method (not recommended): you can pasteurize your milk on top of the stove, but you will need to stand there and constantly stir the bottom of the bot to prevent scorching. The thing is that it takes a very long time for the temperature to heat thoroughly, and it is tempting to walk away. The bottom of the pot will get to a much higher temperature than the top and you need to constantly stir. Trust me, you don’t want your milk to scorch! If you do scorch the bottom of the pan, the burnt milk will stink up the entire house and ruin all of the milk. Then your milk becomes dog/cat/pig/chicken etc. food.
Heat, stir constantly, take the temperature and make sure that the temp remains at 161 for 16 seconds and cool down rapidly (see below).
Double-boiler method (recommended): Far simpler than the previous method is to use a double boiler. This ensures that your milk will not scorch. Basically, it is two pots, one that fits inside the other. You fill the first pot partially with water, and water heats the pan that goes inside. If you are planning on making cheese, a double boiler is a must have. I really like the double boiler that I bought specifically for making cheese. Keep in mind that you will still need to stir, but not at a constant like the other method. Just heat it up, stir, take the temperature, make sure it stays at 161 for 15 seconds and then cool it down rapidly (see below).
I’ve had very good luck with this double boiler that I picked out for making cheese. The price is decent, but the pots aren’t good for much else other than pasteurizing milk or making cheese. They are too flimsy to use by themselves.
Home pasteurizer method (also recommended): The nice thing about the home pasteurizer is that it is essentially a double boiler with a thermometer built in. When it reaches the proper temperature, it will buzz loudly at you to switch it over to the cool down method.
The bummer about the Home Pasteurizer that I purchased is that there is a definite learning curve in putting it together, and it is very expensive–in the vicinity of $300 or more.
I purchased the SafGuard Home Pasteurizer from the Dairy Queen’s website, which was the least expensive when I was shopping. Note that I recommend The Dairy Connection for yogurt and cheese-making supplies.
Another option that I did not know about when I was shopping is the Hoegger version. Hoegger is a one-stop shopping source for all things related to goat care, and they are extremely helpful over the phone. When I purchased my pasteurizer, I had some questions about how to adjust the thermostat, and the folks on the phone at The Dairy Connection were clueless as to how to use it (in fact they did not know that the thermostat was adjustable).
The cooling down procedure is also very important. You will need to cool down the milk significantly before putting the milk in the refrigerator (or freezer). This is because if you were to stick a big vat of milk in the refer without cooling it down first, it would take forever to cool down (therefore spending too much time in the temperature danger zone), and likely the heat given off would raise the temperature of the whole refrigerator, potentially spoiling the rest of the food in the fridge.
With the home pasteurizers, there is a built in mechanism and instructions on how to rapidly cool the milk down. But, if you are using the double boiler or some other device, you will need to put the pot of milk into the sink and surround it with cool water or ice. Keep the pot covered, as to avoid getting water in the milk and it will help prevent a skin from forming on the top of the milk.
I like to store my milk in the refrigerator in half gallon mason jars. If you’ve got a Bi-mart nearby, they have the best prices on mason jars.
I hope this helps you. Please let me know if you have any questions, I would be happy to help!