Milk Soap

 
 
 

The tan soap on the left was made with what I call the traditional technique using liquid goat milk.   The lavender soap on the right was made with powdered goat milk added after the soap was done cooking. 

The techniques that are listed here will also work with soy, or cow milk.  Soy, cow and goat milks are available in powdered form at some grocery and healthfood stores as well as at some online soap suppliers. 

If you are using soy milk be sure to buy the plain soy milk, not soy beverage.  Soy beverage does not work nearly as well in soy milk soap.

Any milk adds richness, and a creamier lather to soap.  It also is slightly moisturizing.  I superfat all of my milk soap recipes 5-7% and do not count the extra fat that the milks contribute to the recipe.  With any milk soap, they need a few days to dry out completely.
 

To make traditional (brown) milk soaps with liquid milk: 
Any milk contains a bit of milk solids.  They are protiens, sugars,and fats.  Think of cheese, it's all milk solids.  It is because of this that you will need to use more milk than you would use water in a recipe.  You add more milk to compensate for the solids and to make sure there is enough liquid in your recipe to keep your soap from drying out too much while it is cooking.  I calculate milk usage by dividing the amount of oils in the recipe by two.  This means that if I am using 30 ounces of fats and oils in a recipe,use 15 ounces of milk.  This makes the soap extra creamy without being too moist for too long. 

Here's one of my favorite goat milk soap recipes:

  • 25 ounces olive oil
  • 5 ounces coconut oil
  • 15 ounces (by weight) very cold liquid goat milk
  • 4 ounces lye 


    • Add the lye to the goat milk very slowly.  Make sure that the milk is very cold, but it doesn't have to be frozen.  It will turn a light yellow color.  I do this in the sink just in case the milk bubbles over. 

    Add the goat milk lye mixture to the rest of the oils (melt the coconut oil and then add the room temp olive oil to it).  Stir with a stick blender until the mixture traces, and then put it in the microwave on MEDIUM heat.  DO NOT use a higher temperature setting or the soap will separate and turn very brown.  I check the soap every minute or so and stir it with the stick blender. 

    After cooking the soap on medium heat for at least 10 minutes I turn the heat up to medium high or high and continue cooking and stirring.  Check on the soap every 30 seconds to prevent the soap from boiling over. 
     

This recipe takes about 20 minutes to cook.  That is much longer than the cooking time for this recipe without goat milk. (but worth the extra time).  It's a little trickier to work with traditional milk soaps, so I recommend making a few plain all-veggie recipes before trying your hand at making traditional milksoaps.  All veggie batches cook much faster and are somewhat easier to deal with than any recipe containing animal fats.
 
To Make Milk Soaps Using Powdered Milk: 
This is the easiest way of making milk soaps.  It will work with any recipe, and the soap will not turn brown. 

The powdered goat and soy milks that I buy come with a coffee scoop (1/8 cup).  I add one scoop per pound of oils in my recipe.  I mix the powdered milk with just enough water to form a thin paste, and add it to the soap after it is done cooking.  Mix it well, and then add the scent and colorings.  Make sure your soap is fully cooked and not still caustic before you add the milk otherwise it will turn brown.  You may need to give the soap a couple of days to firm up if you are using this method. 

Do not try to discount the water if you are using this method.   It will make it very difficult to stir the soap at the end.  Just give it  a few days to dry out completely.