Saving Organic Milk From Going Bad: Re-Pasteurizing 101

At five to six bucks a gallon, it can be heart breaking to toss a gallon of sour milk down the drain.  After today’s post, you won’t ever need to do it again!  

When your milk begins to approach its due date, simply pour it into a microwavable container or a stovetop saucepan and heat it until it barely boils.  You’ll re-pasteurize the milk by killing the bacteria that would cause it to go bad.  It may strike a few of you as rather icky, but the truth is that when you finish it will last for another week or two.  

My mom used to practice this technique when we were little and I found it quite odd, but now I love being able to prevent a high priced organic product from going down the drain.

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  1. Great tip! I never thought of re-pasteurizing, but it really makes sense. I imagine this can be done with cream, too. After all, the Europeans keep their milk in a box on the shelf when it has been ultra-pasteurized. Do you happen to know what temperature you heat it to?

  2. Great tip–you can also use it for baking.

  3. Gina:
    I did a bit of research and discovered that the official temperature should be 161 degrees. Also, if you are going to use the stovetop, be sure to use a double boiler so that the milk doesn’t scald on the bottom. I haven’t tried it with creme but I too imagine it would work!

  4. that’s great–i didn’t know you could do that!

  5. I thought you were going to say you made cheese which would be another option. (I posted about how to do it here: )
    The tip you gave was very interesting though, I had never heard of that before.
    I wonder if it is the same as ultra-pasturizing? I have heard that you want to stay away from anything that is ultra-pasturized as it is not very good for you.

  6. Wow that is such an interesting tip. I will have to look into it more. We dont have too big of problem with wasting milk. Me and my husband love to drink it!

  7. I never heard of this before! I’ve heated milk but only to add honey, cinnamon, & nutmeg after – yum!

    I don’t think this tip will ever come into use at The Condo. My husband drains our milk dry every couple of days. I’ve joked that since he drinks so much milk, maybe we should get a cow!

  8. Joy, thanks for the additional information. I really like to measure stuff! Like Abbi, I was wondering about what constitutes ultra-pasteurization, so I looked up a few things too. I have not heard that ultra-pasteurized milk is actually bad for you, but just that it’s not as good for you. Ultra-pasteurized milk is heated to 250 degrees Fahrenheit for a fraction of a second. If you tried that on your stovetop or microwave you would probably curdle the milk, so I think that using the method described in this post sounds safe.

  9. I had never heard of doing this, either. I heat milk all the time on the stove (for various recipes) and never need a double boiler.

    Re: ultra-pasturization, I also have heard it’s not AS good for you; not that it’s not good for you at all. Do you think you can re-pasturize milk that’s already been ultra-pasturized? Most organic milk is ultra-pasturized because it comes from so far away. (For example, Trader Joe’s organic milk is from Ohio–I live in Oregon.) I wrote a post about choosing local milk over organic if you can’t have both a while ago.

    Another way you can preserve milk is to freeze it. I was shocked to hear some friends talking about pouring their milk down the drain before taking a trip. Freeze it! You can at least cook with it later.

    Great post, Joy!

  10. I have a friend who freezes milk all the time. You just have to remember to shake it up before drinking it the first time, or it tastes pretty nasty. Otherwise, I really can’t tell the difference from unfrozen to frozen.

  11. I never thought of re-pasteurizing! I am going to share this tip with all of my other frugal girlfriends!

  12. Great tip. My hubby (like the other Lisa’s/Condo Blues) drinks ours before it goes bad. We are also lucky. We have a local dairy where we get cheaper milk. 🙂

  13. Jennifer says

    Do you have to cool it down before you put it back in the fridge? Thanks!

  14. Marshall says

    I have done this with milk that even smells sour. After microwaving it to a simmer, let it cool, it tastes just as sweet as fresh milk!

  15. It is a funny topic but I have even heard that is what the milk companies do. They take the milk that people don’t buy from the stores and repasteurizes it and send it back to the stores for a small price.

  16. It is a really bad idea to ultra pasteurize milk. You are killing the good and bad enzymes and destroying all the nutrients. Better to buy smaller quantities of organic and drink it before it expires.

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