Since I’ve written other articles on soap making, I’ve been asked many times, “How do I make milk based soaps?” While there are a few shortcuts, milk based soap is a bit more difficult than most other cold process soaps, but the end result is well worth the extra effort.
If you haven’t made soap before, we recommend you take a look at our other articles on soap making to familiarize yourself with the process before tackling this milk based soap recipe:
- Homemade Natural Soap for DIY Cleaning Recipes
- Handmade All Natural Soap for Face & Body
- 25 Secrets for Making Amazing Soap at Home
Goats Milk Soap Recipe (& Other Milk Types)
(Makes about 3 cups or 4, 4-oz bars)
You could use any soap making recipe and substitute the milk for the water, but some milks are higher in fat, necessitating the use of more lye to make it work. I’ve used the following recipe and it works great. Depending on what kind of milk you use though, you may need to use a bit of additional lye. I used goat’s milk, and that has about the same amount of fat as whole cow’s milk. Others, such as buffalo, sheep, or yak (yes, yak!) have more fat. Increase your lye to 6.5 ounces for these milks.
- 12 ounces coconut oil (find organic unrefined coconut oil here)
- 15 ounces olive oil (find bulk organic olive oil here)
- 13 ounces other oil – such as lard, sustainably-sourced palm oil, tallow, vegetable shortening, or another comparable oil (see “Additional Notes” section)
- 13 ounces milk
- 6 ounces lye – also called 100% sodium hydroxide (find it here or at local hardware stores)
- 1 ounce essential oils, optional (find 100% pure essential oils here)
- additives such as oatmeal or lavender flowers, optional
- On the day before you make your soap, you need to freeze your milk. Getting it very cold isn’t good enough, it needs to be frozen. I put mine in zip top bags in the freezer and keep it there until I need it. Each bag is pre-measured at 13 ounces so it’s ready to use.
- Then, you need a large glass or stainless steel bowl. (Avoid using plastic, as it may absorb odors.) Put this in a larger bowl or the sink and fill the outside bowl about half full with cold water and ice so it’s very cold. In the inside bowl, place your frozen chunks of milk.
- Very slowly, add your lye and carefully squish it into the milk. A stainless steel potato masher works quite well for this step. Keep adding the lye until it is all incorporated. It will probably not get hot or even warm. Don’t worry about that, it doesn’t need to. If the ice in the outside bowl melts, keep replacing it. It needs to stay very cold. The milk may turn orange or even tan to light brown. This is normal. If it turns dark brown, you’ll need to start over. The milk is scorched at this point. The sugars in the milk are very sensitive and need to be kept very cold to keep them from scorching. And if you smell an ammonia-like smell, that is normal too – just keep going. This smell will fade while it is curing.
- When your lye/milk is ready, keep it on ice while you get the oils ready. Measure your oils using a kitchen scale. Combine oils and heat them slightly until they are about 110° – 125°F.
- When the oils are ready, slowly pour the lye/milk mixture into the oils. Mix by hand for the first 5 minutes and then use a stick (immersion) blender to bring it to trace. If you’ve never made soap before, this is where it gets quite thick, much like pudding. When it comes to a trace, add your essential oils and any additives and pour it into molds.
- Wait 24 hours or more, remove from molds, and cut if desired. Wait 3-4 weeks, turning it every so often so all sides have been exposed to air. You can test the pH with test strips to make sure it’s cured (desired pH is between 8-10), or use the old “touch your tongue to it” method. If you get any kind of tingle on your tongue, it’s not ready yet and will be too harsh on skin if used at this point. (I’ve been doing this since 1995 and that tiny bit of lye on an uncured bar will not hurt you.) Wrap when completely cured.
Additional Milk Based Soap Notes
- Always keep your milk frozen and the lye/milk mixture cold. This is extremely important to prevent scorching.
- Lye should be handled with extreme care as it is caustic and can burn your skin. Keep vinegar handy as it will neutralize any lye burns. I got burned yesterday by reaching for a paper towel. I brushed my arm across the lye jar and didn’t think I actually hit it until later when it started to itch. I wiped it with vinegar, put some ointment on, and it’s not even red today.
- Use only stainless steel or glass as plastic can pick up smells from the milk as it’s “working.”
- Your other oil can be any oil with a comparable SAP value. The SAP value is the amount of lye that it takes to make that oil into soap. (Actually, it’s more than that, but that’s the short version.) I tend to stick with oils like palm and grapeseed, which have benefits for the skin.
- Palm oil is a controversial subject. I have found that Spectrum Foods is the only company that produces sustainably harvested palm oil. (Find it here.) It comes from farmers and is not involved with the rainforest at all. They also make an organic vegetable shortening that works very well in soap.
- To make milk soap with a whiter color either use all clear oils or add small amounts of titanium dioxide.
- If your soap mixture doesn’t trace, don’t worry. As long as it is blended well, it will be fine. There have been a few times when my soap didn’t trace and it worked out despite this.
- It’s very common for your soap to turn gelatinous during the the first part of the curing stage. (It’s actually a good thing.) If this happens, do not stir or you’ll upset the balance. Allow it to sit untouched and it will be fine.
Alternative Milk Soap Method
When I’m teaching a class, it’s hard enough to keep everyone together without throwing frozen milk into the equation. So I give them an alternative. Prepare your soap as you normally would using a cold process soap recipe. Then, at the trace, add a few teaspoons of powdered goat’s milk mixed with a bit of oil. I use oil, not water, because it smooths out well and doesn’t get lumpy like it does when mixed with water. You may still get the orange color and some ammonia smell – remember that it’s normal for that to happen. You can still add whatever you want. The color will fade and become a nice creamy color.
I love making milk based soaps because they are so good for your skin. And it helps justify my love for my goats!
Have you tried to make milk based soaps? How did it go? Share in the comments section below!