## Thursday, March 8, 2012

### Review: Measuring in percentages, converting to weight

You'll note that just about every recipe on this blog is measured in percentages that convert into weight. This is because it's more accurate than measuring 1 spoonful of this or 5 ml of that ingredient, which means that we can ensure we have the right amount of everything in our products. If we use a teaspoon of emulsifier, something that comes in pellet form oftentimes, we might be using a heaping teaspoon this time and a scant teaspoon next time, and that might throw the recipe out of whack.

To convert something to weight, just remove the % sign and replace it with the word "grams" and you'll have a recipe that will make 100 grams of something. If you want a 500 gram batch, then multiply everything by 5. If you want an 800 gram batch, then multiply everything by 8. If you want a 200 gram batch, multiply everything by 2. And so on.

If you must do everything in weighed ounces, this gets a little trickier. I would convert the % sign into ounces, then make everything into a decimal, otherwise you're going to get 100 ounces of stuff, which is a lot! For instance 6% emulsifier, would become 0.6 ounces emulsifier, 10% oil would become 1.0 ounces of oil, and so on. It'll make up about a 10 ounces by weight batch of product.

Want more helpful hints? Look to your right to the frequently asked questions section for many many more!

Related posts:
How to convert to weight from percentages?
Weight vs. volume
How to calculate percentages

#### 1 comment:

Catherine said...

Hi. I've had my first epic lotion fail. My question: Can I still use this broken emulsion lotion packed with cosmeceuticals? It has preservative in it so I figure, even if it's not pretty, I assume I can still use it? Just shake it up before each use? Or is there some safety/etc reason I shouldn't use a broken emulsion lotion?

FYI, I got cocky after having a series of successes following your recipes, so I thought it was time to make my own recipe packed with expensive cosmeceuticals.

BTW, I'm pretty sure my problem was I exceeded maximum solubility. I thought maybe I could finagle a higher "average" solubility (eg one thing was 15% soluble in water but another thing was 60% soluble so I thought I could inch the "average" solubility to 20% or so). But no, I think it's like a weakest link thing...the lowest solubility of all your ingredients is the maximum solubility of your entire lotion.

Do you agree with my solubility theory or did I do something else wrong? I would love to make a really concentrated product so I don't have to put 10 different moisturizers on my aging face at night, but maybe that's just not possible.