Milk soap is amazing because it does wonders for your skin. You can read more about milk soap here. Making milk soap can be tricky, but it doesn’t have to be. I’ve made quite a few batches of amazing hot process milk soap, but also had my share of failed batches. Here, I want to share with you my 5 tips on making hot process milk soap.

The most important thing about making hot process milk soap is you have to make sure the milk doesn’t burn when you’re making your lye solution. When adding lye to milk, if you are not careful and patient, you will end up with scorched milk that smells stinky and looks like expired milk with floaty white chunks. This’s because when lye is added to milk, the chemical reaction raises the temperature of the milk so high that it burns the milk. Burn milk is bad. When it happened to me during my first attempt at making hot process milk soap, I almost stopped making hot process milk soap all together. The experience was distressing and discouraging.

If you’ve read my other posts, you know I primarily make hot process soap, aka, crock pot soap. This is because I’m impatient and don’t want to wait 4 to 6 weeks for my cold process soap to dry or cure. It takes only a few days for my hot process milk soap to dry and cure. But making a hot process milk soap is trickier than making cold process milk soap, because the hot process method requires you to cook your soap for about an hour before placing it in your mold. During this cooking process, again if you are not careful and patient, your milk, which is now in your soap, will burn, discolor your hot process milk soap and give your soap an offensive odor.

So, Save Yourself from the Mistakes I made and Follow These 5 Tips on Making Hot Process Milk Soap

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In this post, I assume you know the basic steps of making hot process soap: (1) make lye solution, (2) add lye solution to oil, (3) mix lye solution and oil with a stick blender, (4) cook lye-oil mixture, and (5) mold soap. If you don’t know the basic steps, check out my recipes for Olive Oil Crock Pot Soap, Castile Soap with Olive Oil and Milk, and Easy Homemade Soap for 1st Time Soapers to learn about the different steps of making hot process soap.

Hot Process Milk Soap Tip #1

You have to make sure the temperature of your milk is as low as possible before you add lye to it. I freeze my milk the night before to make sure it’s rock hard when I add lye to it. You absolutely have to freeze your milk until it’s rock hard.

Update: A reader suggested that you freeze 2/3 to 3/4 of the milk, add the remaining milk right before adding your lye. That’s a great idea. You can mix the lye into the milk easier if there’s some liquid in the milk.

Hot Process Milk Soap Tip #2

Create an ice bath when you are making your lye solution. This will help with lowing the temperature of your milk after you add lye to it. In the example below, I use coconut milk. These tips apply to any milk you want to use to make lye solution.

Hot Process Milk Soap Tip #3

Add lye into your frozen milk slowly, a little at at time.

You begin with adding a small amount of lye, around a tablespoon or so into the frozen milk. Stir until the lye is completely incorporated into the milk. Use a heavy-duty plastic or silicone spatula or a whisk to stir. Don’t use anything made with aluminum, because the lye will melt it away. When the lye is completely incorporated into the milk, add another tablespoon of so of lye. Repeat this step until all the lye is added into the milk.

You can see below how each time I add lye, it melts more and more of the frozen milk.

Each time you add more lye, you will see the lye melting the frozen milk almost immediately. Patience is golden here. You can’t add too much lye at once, or it will burn the milk. By adding the lye slowly, you are keeping the overall temperature of your lye solution low and preventing your milk from scorching.

Below is what the lye solution looks like after all the lye has been added. It took me about 15 minutes to add 5 oz of lye into 9 oz of frozen milk. You will notice that the color of the milk has turned to a creamy color with a tint of yellow.

Hot Process Milk Soap Tip #4

When you are cooking your hot process milk soap (lye-oil mixture) in the crock pot, set the crock pot to the lowest setting.

My crockpot has a high, low and warm setting. I use the warm setting. You want to do all you can to make sure your hot process milk soap and your milk doesn’t overheat and burn. Yes, this will mean that your cooking time will be longer, maybe around an hour or so. But cooking at a low-heat is essential if you don’t want any burn spots or discoloration in your hot process milk soap.

Hot Process Milk Soap Tip #5

After your hot process milk soap is fully cooked (when it achieves a Vaseline and gel-like consistency) and before you put your soap in your mold, add another 1/2 cup of milk into your cooked soap.

By adding milk at this stage, you are making it easier for the hot process milk soap to go into the mold, and the added milk will make your soap lighter in color and more nourishing when in use.

That’s it. These are my 5 tips on making hot process milk soap. The one key takeaway about making hot process milk soap is that you can’t rush it, you have to be patient. There’s no cutting corners with this one. But the end result will be worth it. You will not mind the extra time, attention and effort you put into making your hot process milk soap when you get a chance to use it. Your hot process milk soap will feel creamy and extremely nourishing.

Let me know what you think and your experience with these 5 tips on making hot process milk soap. If you like this post, remember to share it and pin it. Happy soaping!