Half & Half Method and Using Natural Colorants in CP Soap
We recently got a two-part technical support question that piqued my interest. In the first part of her question, Lori asked for clarification of when to add milk when making cold process soap using half milk, half water.
Here is the answer:
When we use any milk-type product (cow, sheep, goat, almond, coconut, etc.), we often use what we call the Half & Half Method. We look at our recipe and use 8 ounces of liquid for every 16 ounces of fats. Then we mix 4 ounces water (half of the liquid) with the lye. We mix well and then allow the lye water to cool. When the lye and fat solutions are within 10 degrees of each other, we will combine them and start mixing. When it appears that we are half-way through the mixing process, we will add the other half of the liquid, but this time the liquid is the milk product.
Start with HALF of the liquid as water.
Mix HALF WAY.
Slowly pour in HALF liquid as milk.
Stir gently until trace. Pour into molds.
Here is the second part of the question:
When adding essential oils or paprika or turmeric, at what point is this added to the mixture?
Paprika, turmeric, mustard, etc., all have oil soluble colorants. Remember the plastic spoon you used when making spaghetti sauce, and after washing the spoon in the dishwasher, it was still orange? Those are oil soluble colorants. At the end of this message, I’ll share a hint on how to remove the color from your favorite spoons!
If I want a smooth colored soap and I know I am using paprika, then I will add the paprika to my oils before heating, either by sprinkling it in or putting it in a tea bag. After heating the oils, I will allow the oil to cool and then filter or remove the tea bag which held the ground herb.
If I want a speckled soap, then I will add the paprika at the end of the mixing process, right before I pour the soap into the molds, and let the specks sit in the soap as it cures. The specks will bleed color, and you will get a freckled look across your bars of soap (a very cool effect).
Always make sure you still have the same weight of oils after filtering out the herbs before adding the lye solution and mixing. Some people have been known to remove an entire ounce of oil with the paprika!
If you don’t like the idea of weighing the oil after the paprika has been filtered out, then color just one oil ahead of time. For instance, take 5 pounds of coconut oil, add in about 5 tablespoons of paprika, and heat until liquid. Allow the oil to infuse for 30 minutes, stirring occasionally. Strain the paprika from the oil, and place in an air-tight container with a label noting it is paprika-infused coconut oil. When you are ready to make soap, use the paprika-colored coconut oil in place of the plain coconut oil in your recipe.
There are many natural colorants out there. Think anatto, chocolate, algae, fruits, vegetables, and herbs. Please note that some colors are not stable in bright light (chlorophyll), and some are not stable in alkaline environments (meaning with lye), such as beet juice, cherry juice, all reds, and most purples. Yellow, orange, and some greens are the easy ones. Brown is also easy.
As for scents, those always go in when you have achieved trace, which is when the soap batter has emulsified, not necessarily when the soap batter has thickened. It is helpful to know how your scent may affect your soap batter. Some scents cause the raw soap batter to rapidly thicken, and others can cause discoloration. This can be true with essential oils as well as fragrance oils. If you are not sure how a fragrance or essential oil will react in a batch of soap, contact the supplier for assistance or make a one-pound test batch.
Now, how do you get that spoon clean?
Grab the orange-tinted spoon, the one that was once white, and grab the can of shortening. Apply a thick layer of shortening to the spoon and let it sit 12-24 hours. Remove the fat from the spoon with a paper towel or old newspaper. The shortening was orange, wasn’t it? Repeat as needed to fade the color on the spoon. Older stains are harder to remove. In this process, you are using only food items, no harsh cleaners, which are inedible. Isn’t that neat?
After reading the technical support emails, I made a couple of test batches, one using paprika-infused oils and the other adding the paprika at the end of the process. I wanted to see for myself (and show you) the end results.
If you’d like to give it a try, gather some supplies!
I used this soap recipe:
Recipe in percentages
31.25% Soybean Oil
Please begin with this blog post if you have never made cold process soap before! Even better, read all 12 posts in the series. Experienced soapers, grab your gloves and safety glasses, make sure you’re wearing long sleeves and close-toed shoes, and get let’s get started.
I began with the infusion method.
First, weigh the oils into the microwave-safe container. Melt the oils and then stir in a tablespoon of paprika. Set aside.
Weigh the water in one jar or measuring cup and the milk into another. Set the milk aside.
Weigh the sodium hydroxide, and mix it into the water. Set aside to cool.
After about 15 minutes, filter the paprika out of the oils, pouring through a cheesecloth-lined strainer into an empty container. Squeeze out all the oil you can from the cheesecloth. Then wipe out the empty container the infused oil was in originally to remove any specks of the paprika, place it on the scale, zero the scale, then pour the filtered oil back into it. When I did this, I discovered I had lost about a half ounce of oil. I used olive oil to get back to the 16 ounces of oils required for the recipe.
After determining the temperature of the oils and lye water were within 10 degrees of each other and not too hot for soaping with milk products (below 90 degrees is a good rule of thumb), I mixed the lye solution into the oils. When I saw that the batter was emulsified, I poured in the almond milk and continued mixing. The milk seemed to thicken the batter quickly, so I hastily stirred in the fragrance oil and poured the batch into the waiting soap stone mold.
Now to repeat the process, but this time I’ll add the ground paprika at the end of the mixing process when I put in the fragrance oil. I did everything the same as before, except I did not infuse the paprika into the oil. After mixing the oil and lye solution, adding the milk, and stirring in the fragrance oil, I spooned a tablespoon of paprika into the soap batter and stirred thoroughly. Then I poured that batter into a second soap stone mold.
Both soaps cured in the mold for almost two full days before I got back to them to unmold. They are so pretty and so different from one another! The smooth, apricot color of the soap using the infused oil method is beautiful. The soap with the paprika added at the end is freckled and appears much darker, but when I look closely, I can see the same base hue as the infused soap. I expect to see the speckled soap become darker as it cures and the paprika bleeds, but I hope the infused soap stays the same rosy hue. I really like it! That method would make a lovely color for a rose-scented soap.
Do you use natural colorants when soaping? What is your favorite? Have you had any surprises? We’d love to hear about your experiences!