The search for the “perfect” cold process soap recipe is both fun and a little daunting. There are so many different factors to consider, including the ingredients, soaping method and mold. One factor that you should not feel limited by is the size of the recipe. No matter how much soap the recipe makes, you can resize the recipe to fit whatever mold (or molds!) you have. Resizing a recipe does require a little bit of math, but once you understand the basics of the Lye Calculator, it’s super simple.
If you have found a recipe that looks perfect but makes too much or too little soap, it’s time to resize. The first thing to understand about cold process recipes is the difference between the oil weight and total yield. A cold process recipe is comprised of oils, a liquid like water and sodium hydroxide lye. These three components come together to create the total yield of a recipe.
For example, if you’re using the 10″ Silicone Loaf Mold, which holds about 50 ounces, the total yield of the recipe should be about 50 ounces. The total oil weight will be less than that because it does not take into consideration the water and lye, which will add several more ounces to the recipe. If the recipe does not tell you the total yield of the recipe, you can add up the oils, lye and distilled water to find it.
Let’s look at the Lemon Poppy Seed Cold Process Soap recipe as an example. It’s a simple recipe that is made up of coconut oil, olive oil, palm oil and rice bran oil. Combined, the total oil weight of this recipe is 33 ounces. To find the total yield of this recipe, add the sodium hydroxide and distilled water. The total yield of this recipe is 48.4 ounces.
Now, let’s say that you love this recipe so much that you want to make it in the 5 Pound Mold with Sliding Bottom. I don’t blame you…this project is so fun. =) The 5 Pound Mold with Sliding Bottom holds 5 pounds of soap, which is equivalent to 80 ounces. The easiest way to resize the recipe is with the Lye Calculator. If you’ve never used the Bramble Berry Lye Calculator, you may want to check out the Using the Bramble Berry Lye Calculator post to learn the basics.
To resize the Lemon Poppy Seed Cold Process recipe, input the oil amounts from the original recipe into the lye calculator and select the superfat level. This recipe has a superfat of 5%, but you can change it if you’d like. Then hit “Calculate” at the bottom of the calculator. See the results below.
Now it’s time to resize it! See the section at the bottom that says “Resize Batch”? There is a small box where you can input a new oil weight. Currently, the oil weight for this recipe is 33 ounces. Choosing a new oil weight is a little bit of a guessing game at first. I know that I want the total yield of my recipe to be about 80 ounces, but I don’t know what the exact oil weight should be. That’s okay, because you can resize the batch as many times as necessary.
I’m going to take a guess and input 50 ounces, then click “Resize Batch.” You can see the new resized recipe below. With an oil weight of 50 ounces, the new total yield of this recipe is 73.16 ounces. That’s closer to 80 ounces, but not quite there. Time to resize the batch again!
This time, I entered 55 ounces for the oil weight and the total yield was 80.97 ounces. Perfect! I also tried 54 ounces, which gave me a total yield of 79.50 ounces. Either amount would be fine, but I prefer having a little bit of extra soap just in case. You’ll notice that in all of these recipes, the ratio of oils stays the same. When you resize the batch, the ratio of all the ingredient stays the same.
Once the recipe is resized, keep in mind the fragrance oils, colorants and other additives will also need to be resized. The Fragrance Calculator makes it easy to find out how much fragrance oil is safe to use in the recipe. You can then decrease the amount depending on personal preference. The Lemon Poppy Seed Cold Process recipe uses a blend of Champagne and Lemon Verbena Fragrance Oil. The blend uses two parts Champagne to one part Lemon Verbena. When resizing, keep the ratio of the blend the same for a similar smelling scent. But remember, soaping is all about personal preference so feel free to experiment and change blends depending on what you love. =) Check out the Fragrance Oil Blending Tips post for more information on creating your own blends.
Check out the Fragrance Oil Blending Tips post to learn more about creating your own blends.
If you are not resizing the recipe in an even amount (halving, doubling, tripling, etc.), it can be tricky to figure out how much colorant you’ll need. I generally recommend preparing more colorant than what you’ll think you need. That way, you know you’ll have enough. I always prefer having a little extra colorant that I can save, rather than having to quickly disperse more while soaping. Then, you can store any leftovers in an airtight container in a cool, dry place. They will have the same shelf life as the oil they’re dispersed in. Learn more about the shelf life of oils here. Just make sure to mix well before using, as the colorants will settle. For information on how to disperse colorants, check out this video on Soap Queen TV. You may also find the How to Get Vibrant Colors in Soap post helpful.
I always like to disperse more colorant that what I think I’ll need for my recipe, just in case!
If you prefer, you can resize a cold process recipe without a lye calculator, but it does involve more math. Even though I’m fairly confident in my math skills, I like to use the calculator just to make sure everything is correct. How do you resize your cold process recipes? If you have any tips or tricks, I would love to hear them!