How should a lotion recipe look? The general standard is to have a heated water phase, heated oil phase, and a cool down phase. A lotion should have a water, oil, emulsifier, and preservative as the minimum. An ideal recipe will be written in percentages or, at the very minimum, the total of all the ingredients should total 100%.
Why is this? Because it's so much easier to embiggen a recipe for larger batches when it's written in percentages, and it's much easier to substitute ingredients. When it's written in percentages, you can see very clearly what is in the recipe and make changes if it's not written properly.
Here's a for instance...
18 grams water
15 grams oil
3 grams Polawax (emulsifier)
1 gram preservative (liquid Germall Plus)
Will this recipe work?
We know for an oil in water recipe, we want the water to be more than 50% of the total recipe. In this case, we have 37 grams of product and 18 grams of water, for a grand total of about 48.6% water, which means we don't have enough. Do we have enough Polawax? We know for Polawax, we want to have 25% of the total oil phase in emulsifier, so if we're using 15 grams of oil, we want to have 3.75 grams of emulsifier (round it up to 4 to make life easier!) And we know that we can only use 0.5% liquid Germall Plus maximum in a recipe - at 1 gram in 37 grams (2.7%), we're at almost six times the maximum suggested usage levels! EEK!
So can we re-write this? Yes. Just figure out how much of each ingredient we have in the recipe.
18 grams of water - 18/37 (the amount of water divided by the total recipe amount) = 48.6% water
15 grams of oil - 15/37 = 40.5% oil
3 grams Polawax - 3/37 =8.1% Polawax
1 liquid Germall Plus - 1/37 = 2.7% liquid Germall Plus
Okay, so we know how much of each ingredient we should have and we know how to modify them, right? Switch the preservative to the suggested usage rate - so 0.5% liquid Germall Plus - add 0.5% to 1% fragrance oil, and you've got yourself a recipe.
Click here for information on solubility!) Put anything that is temperature sensitive into the cool down phase, regardless of their water or oil solubility. (Confused about when to add an ingredient? Click here for some guidelines!)
HEATED WATER PHASE
HEATED OIL PHASE
COOL DOWN PHASE
0.5% liquid Germall Plus
1% fragrance oil
I've increased the emulsifier to make up 25% of the oil phase. (If you don't know why I would do this for Polawax, click here. This isn't the rule for every emulsifier - just Polawax!) I've decreased the preservative to a safe level, and I've added some fragrance. My recipe adds up to 100%. I still wouldn't make this recipe - it's so boring with no humectants or film formers or other wonderful things, and I'm never sure about those recipes that skirt the edge of the 50% oil or water mark - but at least I know I'm using my ingredients at safe levels.
For more information on choosing recipes, click here for a post on how to know if you have a good recipe or not!
What should you do if you encounter a recipe that doesn't work? My suggestion is to write to the recipe writer and let them know of your experiences. It could be that you make some kind of substitution that didn't work or it could be that the recipe is just lousy. Present this information to them in a questioning way - "Hey, Swift, I'm just wondering why this recipe didn't work for me?" versus "You suck!" - because there's always a chance the problem lies with your ingredients and methods, and there's far too much meanness out there these days! I know that I want to know if a recipe didn't work for you, but some recipe writers do not. Be prepared for attitude, and if the recipe writer doesn't want to hear it, let it go, but warn your friends or post something on the blog so other readers won't be in the same mess in the future. (Can you tell this has been my experience lately? I never know when to let go because I always see people as wanting to learn and I can't grasp when they want to keep their heads in the sand!)
If you encounter a recipe on this blog that didn't work for you, please write to me (firstname.lastname@example.org) with the link to the specific recipe, information on which ingredients you might have switched, and information on your process! I really do need those details, and if you don't include them in your e-mail, I'll have to write you back and ask for them before answering the pertinent questions!
Join me tomorrow for more helpful hints on formulating!