Now you know the basics of lotion making, let's tweak our recipe to make a cream. What's the difference? A cream is much thicker than a lotion due to the lower water content. A cream belongs in a pump bottle or a jar; a nice bottle with a disc cap that you have to squeeze isn't going to be suitable.
The only true difference between a lotion and a cream is the water content. I'd use 60 to 65% water phase for a cream (versus 70 to 80% for a lotion). I'd add more butters to the cream to thicken it up (it doesn't have to have more butters, but this is what I'd do), and I'd tend to add more thickener like stearic acid or cetyl alcohol. (Stearic acid for something you want to stay on difficult places like elbows or feet; cetyl alcohol for a glidy cream, like a body butter).
So how do we go about making a cream?
The basics are the same - oils, butters, water, emulsifier, thickener, preservative, fragrance - but we change the amounts to get what we want. And we're going to add the humectants!
If I wanted a foot cream, something thick and rich and decadent that will stay on, I'd include a few humectants - glycerin, because I'm not worried about stickiness - and olive oil - it does double duty. I want something very emollient, so I'm going with some nice butters are heavier oils. And I'm using stearic acid so I can make sure it is a tenacious cream (is that really the right adjective? I want something that will stay on!)
RECIPE FOR A THICKER FOOT CREAM
15% oils - olive and rice bran are great choices here (we want heavier oils)
10% butters - I'd choose shea and/or mango here as they are both very emollient
3% stearic acid
COOL DOWN PHASE
0.5 to 1% preservative
1% fragrance or essential oil blend
Addition...3% menthol crystals - add this to the oil phase if you have them. (Your workshop is going to be very menthol-y, and I suggest keeping your face away from the warm oil container, unless you're my best friend, then you'll be huffing it and going "aaah!") Take 3% from your water phase to compensate.
Or you could choose an essential oil blend and add it at 1% (see the cool down phase above). I like a blend of 1 part each eucalyptus, camphor, and peppermint for a foot cream (smells like Vicks!), which helps circulation and feels nice a cool.
1. Weigh out your water phase in a heat proof container and put into a double boiler.
2. Weigh out your oil phase in a heat proof container and put into your double boiler. (If you are using menthol crystals, add this to the oil phase.)
3. When both containers have reached 70C, weigh out your water again, then add it to your oil container.
4. Blend with a hand mixer or stick blender for at least 3 minutes. Repeat this process as often as you would like until the temperature reaches 45C.
5. Let cool to 45C, then add your fragrance or essential oil and preservative. Mix well with your hand mixer or stick blender, then let cool.
6. You can pour the mixture into a jar now, but leave off the cap and let set for a few hours. Or you can wait until the mixture reaches room temperature, then spoon into your jar. Or you could use a pump bottle or malibu bottle as this will be bottle-able if you have a way of squeezing it out!
You've made a cream! Hooray! If you want to make this for your body, I'd suggest many of the same ingredients, but you could substitute cetyl alcohol for stearic acid (more glidy), lighter oils, and leave out the menthol. Oh heck, let's just make a body butter tomorrow, eh?