This post was updated in 2019 with the new Bramble Berry Lye Calculator design.
Customizing soap recipes is one of the many advantages of making products from scratch. There’s a lot of joy in experimenting and finding the perfect combination of ingredients that make your skin feel great. The Lye Calculator makes it easy to do just that.
All you have to do is plug in your oil and superfat numbers and the calculator determines how much liquid and lye you need for the recipe. Learn how to use the calculator below, and find soap making supplies here.
ONE: Choose the type of soap, unit of measurement, and the superfatting level. Click “Next.” Note: Liquid soap is made with potassium hydroxide, solid soap is made with sodium hydroxide.
TWO: The oils are listed in alphabetical order. Find the ones you plan to use and enter the amount in the box to the left. Click “Next” at the bottom of the list.
THREE: Your recipe will appear. The lye and liquid amounts are listed at the top, followed by the ounces or grams and percentages of oils you chose.
FOUR: It’s easy to edit your recipe. If you want to change the type of soap, unit of measurement, superfat, or oils, select “Edit” in boxes 1 and 2. You can also click the “Ounces Grams” button to change the unit of measurement.
FIVE: If you need to adjust the size of your recipe, select the “Resize Batch” button and enter a new oil weight.
SIX: When your recipe is complete, give it a title and leave notes if you like. From there, you can print your recipe. There's also an exciting new feature - you can add your recipe to your favorites and refer back to it whenever you like. Just click the heart icon in the top right-hand corner.
The superfat level is the amount of leftover oil in your recipe that’s not turned into soap. Essentially, it’s free-floating oil that adds extra luxury to your bars and acts as insurance in case of small measuring mistakes. We typically superfat our recipes at 5% because it adds moisture without making the bars too soft. That’s a good superfat level to use if you’re just getting started.
You may find you like the level lower or higher as you continue to work on your recipe. Right now the calculator only goes up to 10%, so if you want a higher superfat you’ll need to find that amount manually.