Warning: If you start making soaps with milk, you will never want to stop!
Making soap with milk is a tedious, but very rewarding process. It is very similar to making cold process soap with a water/lye base, but timing is a bit more crucial and the use of a blender is required. Personally, I use a stick blender when making all of my soaps, including milk based soaps. I have heard people recommend using a regular kitchen blender when making milk based soaps since the soap must be blended the entire time, and not in spurts. Stick blenders aren’t really made to be used for extended periods of time so if you use one, be prepared for it to burn up. Thus far, I’ve had good luck with mine, but that could change at any time-I just think it’s easier than a full blender.
In either case, a blender is must. Milk based soaps tend to separate during saponification. The use of a blender forces the mixture into a thorough, even saponification.
Key Points when using Milk
• Use goat milk if you can find it! It has a decent amount of milk fat in it, and it’s cream is naturally homogenized (meaning the milk and the cream do not separate).
•Milk should be pasteurized, then frozen to stabilize it before using. Most milks sold in the store have already been pasteurized, and only need to be frozen.
Measure and heat your oils before making your milk/lye solution. You can’t let the milk/lye sit for too long once it has been made or the fats in the milk will start saponifying and clumping.
• When making a lye solution with your milk, it is important not to burn the milk! To avoid scorching, fill your sink with water & ice to make a cold water bath that your lye pitcher can sit in. Use partially frozen milk, and add your lye to it VERY slowly. It should take upwards of 15 minutes to completely mix all of the lye into the milk. You should try not to let the mixture go about 130 or so…
•From here, follow your basic soap making instructions, but be sure to use your blender the entire time until trace!