How to Pasteurize Milk at Home
When you are working with dairy animals and raw milk, there are some occasions when you might want to sanitize your milk. Thankfully it is very easy to pasteurize milk at home.
What is pasteurization?
Here’s a direct quote from Gianaclis Caldwell’s The Small Scale Dairy. “The process, named after Louis Pasteur, in which substances are exposed to heat to limit or destroy any present bacteria for the purposes of food safety or to extend shelf life.
Why do we pasteurize milk?
Human Consumption
There are literally books written on the topic of pasteurization and how it came to be. Here is a really quick version.
Back around the time of the industrial revolution, they started keeping dairy animals, mostly cows, in cities. They were wanting to produce milk closer to where it was being consumed.
Long story short, the animals were not in good conditions nor were they fed optimal diets. Add in filthy living conditions for many people, issues with refrigeration, and immoral activity like adding sawdust or unsanitary water to milk to increase volume, you have a recipe for a lot of sick people.
Pasteurization became the standard at this time as a way to mitigate these issues. Check out my sources below if you’d like to learn more about the history of pasteurization.
Animal Consumption
There is a nasty disease called CAE that can be transferred from the milk of mama’s to their babies. Some folks use pasteurizers to kill this bacteria in the milk to make it safe for feeding back to goats, sheep, etc.
What tools do I need to pasteurize milk?
To pasteurize milk at home all you need is a clean stainless steel pot and a clean thermometer.
Do I need to pasteurize my milk?
That is entirely your call. Perhaps you have a family milk cow but raw milk makes you nervous. You can simply pasteurize the milk and you’ve got just about as good as store-bought.
For me, I will occasionally pasteurize my milk if I at all feel like it needs to be.
Here’s an example: The other day after filtering my cow’s milk, the filter had a little more grit in it than I’d like to see. And when I say “more” I mean it was still at most 1/8 a teaspoon in the filter of cow hair and little speckles.
Rather than give all that good milk to the chickens, I simply pasteurized it.
If my cow smacks her tail in the milk, flies land in it, a chunk of poop flies in there or something, then no amount of pasteurizing makes it feel safe to me. The chickens get a special meal that day.
How to Pasteurize Milk at Home
Add your milk to your stainless steel container. If possible, a double boiler setup works best to avoid scorching your milk. You can absolutely still do this just with a big stock pot on the stove. Just keep an eye on it to stir often.
Next, see below for what temperature you should heat your milk to for your given preference.
For me, I heat it to 145 degrees F, then maintain it at that temperature for 30 minutes. If the temp goes above that, it is fine. However if it dips below 145 then you need to start your half hour all over again.
Remove the milk from the heat after 30 minutes and chill immediately.
That’s it! Super simple.
What temperature does milk need to be heated to be pasteurized?
Milk needs to be heated to a minimum of 145 degrees F (63 degrees C) and kept at that temperature for thirty minutes. It is believed that this temperature will kill any bacteria or pathogens but will still keep the flavor and full nutritional benefits of the milk. (Source 2)
You can also do what is called High Temperature Short Time (HTST) pasteurization and heat the milk to 161 degrees F (72 degrees C) and maintain it for 15 seconds.
The International Dairy Foods Association has more information on different levels of pasteurization including Ultra Pasteurized.
Legal Definition of Pasteurization
Even though you are legitimately pasteurizing milk, please be aware that this is still not legally considered “pasteurized”. In order to have legally pasteurized milk, it must be heated in a commercially approved pasteurizer that is inspected by a government agency. Whoever is operating the pasteurizer must past a written exam as well as be observed and approved operating the pasteurizer.
Pasteurizers
If you plan on pasteurizing a lot of milk for home use, you might consider investing in a small pasteurizer for personal use, such as this one at Valley Vet supply.
If you are looking at a commercial pasteurizer (one you could use for selling pasteurized milk or dairy products), be prepared to spend $3,000 for a tiny one, and starting more around $10,000 for a larger one.
Will Pasteurized Milk Spoil?
Yes. Raw milk doesn’t spoil but rather “sours”. Pasteurized milk I find has a shorter shelf life than raw milk and it will get nasty and smelly when it spoils. This is because all the good bacteria is gone so it doesn’t ferment, it just goes rotten.
Is pasteurized milk safer and better for you than raw milk?
This is a topic I am not going to dip my toe in. Reasonable people can and will disagree on this.
Some sources will say raw milk has minor if any benefits to pasteurized. Some sources say just the opposite.
You’ll find some experts that say raw milk is incredibly dangerous. Others say it is perfectly fine if handled correctly, and that in fact pasteurized milk causes plenty of illnesses itself.
In the end this is an area where you need to do your own reading and decide what makes the most sense to you and your family.
I will say, raw milk is fully legal in many states. It is completely legal in the UK and Northern Ireland, France, Germany, Holland, Belgium, Switzerland, and on and on.
Watch and Learn
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Sources
- The Devil in the Milk by K.B. Woodford
- International Dairy Foods Association
- Keeping a Family Cow by Joann S. Grohman
- The Small Scale Dairy by Gianaclis Caldwell
- The Small Scale Cheese Business by Gianaclis Caldwell
