Thursday, February 10, 2011
Learning to formulate: A note about percentages
So when I'm talking about increasing the oil phase or decreasing the water phase, I'm talking about the percentages those phases make up in the lotion. If we have a 69.5% water phase and a 29% oil phase, but want to increase the oil amount to 40%, we'll have to decrease our water phase by 11% to keep that 100% total at the end.
Percentages make life easier when you're formulating. Let's say you have a recipe and want 250 grams of it. Then multiply all the numbers by 2.5 to get your new amounts. If you want to make a 1000 gram batch of lotion, then multiply all the numbers by 10. If you want a 50 gram batch, divide all the numbers in half (not so useful for lotions, but great for lip balms or lotion bars).