You can: You can add milk to any soap making recipe by just incorporating the milk in one of the three methods above. The recipe I used was:
27% palm oil27% coconut oil27% olive oil5% castor oil14% almond oil
The actual recipe to make a 2 lb. batch of soap was:
5.3 oz. palm oil5.3 oz. coconut oil5.3 oz. olive oil1 oz. castor oil2.75 oz. almond oil2.9 oz. lye5.8 oz. water.9 oz. fragrance oil
Important Note: When you are calculating a recipe using heavy or whipping cream, be sure to take into account, or at least be aware of the extra fat content in the cream. Heavy cream has 36% milk fat in it, as compared to 4-6% fat in goat’s or cow’s milk. You may want to adjust your recipe to allow for that extra fat. I cover two ways to do this on the last page of this tutorial - or jump right there now.
Freeze the Cream Ahead of Time
To get started with method #1 (using the milk in place of water in the lye solution), you’re going to need the cream to be frozen. - so freeze the heavy cream (or whatever milk you’re using) in an ice tray. While that’s freezing, we’ll move on to method #2, which is using a double strength lye solution and adding the cream directly to the oils.
Method #2 - Making a Double Strength Lye Solution
For method #2, we’re going to make a double strength lye solution. My recipe called for 5.8 ounces of water and 2.9 ounces of lye. I divided the 5.8 ounces of water into 2.9 ounces of water and 2.9 ounces of milk. Using just the 2.9 ounces of water and 2.9 ounces of lye, I made the extra strength lye solution and set it (safely) aside to cool.
Weighing out the Frozen Cream
I then measured out 2.8 ounces of the cream. (Note: If you’re using method #2 and adding the milk/cream directly to the oils, the milk/cream really doesn’t have to be frozen - but it is more convenient to measure and store it this way.)
Adding the Cream to the Oils
Measure out and melt your oils as you would in any other batch of soap. When they are fully melted, add the cream (liquid or frozen) to the warmed oils.
Blend the Cream into the Melted Oils
Blend the cream into your melted oils using your stick blender. You’re not trying to reach any sort of trace or anything. It’s just good mixing of the ingredients.
Mix the Lye into the Cream/Oil Mixture
Like you would any other soap batch, slowly and carefully pour the extra strength lye solution into the melted oils and cream. Blend it with your stick blender until you get a light trace. Add fragrance and/or color after you get to a light trace and pour it into your mold.
Poured Soap (Using Method #2) In the Mold
As you can see, the soap got a good thick trace but is otherwise nice and smooth. (The fragrance oil gave it a little bit of a beige color in this batch.) Set the soap aside and unmold/cut it in about 24 hours.
Method #1 - Making the Soap with Full Milk
Now, back to method #1. Take the full amount of water that your recipe calls for and measure out that amount in cream cubes. Put them in your lye pitcher in a couple of inches of cold water in the sink. Then slowly add the lye to the cubes a tiny bit at a time. Add a little lye - stir a little - wait a couple minutes. Add a little lye - stir a little - wait a couple minutes. Add a little lye - stir a little - wait a couple minutes. For a video demonstration of this, watch my Making Goat’s Milk Soap Video
Stir into a Lye & Milk Slush
The heat from the lye reaction will melt the ice cubes. When all of the lye is added, you’ll have a lye and cream slush.
Cream Slush Thickening Up
Here is one part where using the heavy cream will be somewhat different than goat’s milk. Because the fat content of heavy cream is so much higher than goat’s milk (36% vs. 4-6%) the fat in the milk is going to start to saponify and turn into soap in the lye pitcher. It’s going to get very thick - more of a lye-cream glob rather than a slush like goat’s milk.
Add the Lye-Cream Mixture to the Oils
Scoop out the lye-cream mixture and add it to your melted oils. Take a few tablespoons of water and use it to make sure that you’ve gotten all of the lye-cream mixture out of the pitcher and into the pot with the oils.
Blend the Lye-Cream Mixture in with the Oils
Before you start stick blending, just make sure that the lye-cream mixture has fully dissolved and mash out any big chunks. Then stick blend the mixture like you would any other batch of soap. Add fragrance and/or color at trace and pour it into the mold.
Thick & Grainy Soap in the Mold
This batch ended up being really thick and kind of “grainy” from the heavy cream. I blended it as best I could - and then poured it into the mold. You can see the difference in how thick this batch was from the soap I made with the 50:50 blend of water and cream.
Finished Heavy Cream Soaps & Tips
Here are the finished soaps about 1 week after unmolding. The method #1 soap is on the left - you can see it’s not as smooth as the method #2 batch. The color difference is from the fragrance oil - both batches were about the same color before I added the fragrance. Which method works better? They both work equally well, but I must admit, method #2 works better for me, especially with super high-fat content milk like heavy cream - you get a smoother pour and a smoother final soap. Another important note: When calculating a recipe with heavy cream, it helps to keep in mind the fat content of the cream. Heavy cream has a lot more fat than other milk - upwards of 30-36% vs. 4-5% in goat’s milk. The fat in the goat’s milk doesn’t throw the superfat % off by very much - but the heavy cream can. If I calculated my recipe normally with a 5% lye discount and used the heavy cream in place of 100% of the water (method #1), I would increase my superfat to about 14%. If I used the 50% water 50% milk (method #2) I increase the superfat to about 9%. Part of what traditionally makes milk soaps more moisturizing and gentle is that extra superfat. But if those percentages are too high for you (Susan Miller Cavitch would love them!), here are two ways to compensate for the extra fat: Both methods of calculation work fine - and making no adjustment to the recipe is fine too, although a 14% superfatted soap is going to be more prone to spoiling over time. Obviously, option #2 takes a lot more math and calculation, but it is a way to really accurately keep your superfat/lye discount consistent with the rest of your soaps. Regardless of whether you use method #1 or method #2 - and whether or not you adjust for the fat content, you’ll find that your soaps made with heavy cream are rich, creamy and luxurious - and still lather well too.
