If you're new to lotion making, Heidi L asks: I can't mentally get past this one super basic concept... I understand the idea of heat and hold, I get the mechanics of double boilers. But how on earth do I control the temperatures of the water and oil phases? You list the minimum temp, but what is the max each phase can get before we start to see degradation of the beneficial properties of our ingredients? (I do of course realize that will vary based on exactly which ingredients I choose, but I'm hoping for a basic rule of thumb). I think you may have said 85 degrees somewhere, but does that apply to both phases? Then, I know the two phases need to be about the same temp when we combine them, but how close is close enough? I keep imagining having these 2 pots constantly on and off the heat, in and out of the water baths, stove on, stove off, as I frantically try to achieve and maintain a specific even temperature for 2 pots simultaneously. I can't help but imagine this horribly comical juggling act! Is there a trick to it, or is the reality of it just not as difficult as this frantic scenario I've built in my head?
It really isn't that difficult! If you're using a double boiler, the temperatures will increase slowly so you can monitor is quite easily. Just get yourself two nice candy thermometers and check on them from time to time.
This is why I don't suggest using microwave ovens. A few seconds too long and the metaphorical weiner dog has bitten through your vein and you're spewing blood everywhere! (Okay, you get the picture. No need for more gore, eh? This isn't the Walking Dead, after all!)
In all my years of making stuff, I've never had an oil get anywhere near a smoking temperature, let alone too hot to use in a lotion. I think the highest has been 80˚C. I wouldn't want anything to get over 85˚C because that's pretty high and can hurt you if you spill it. (I have no evidence I can point to for this number, but I remember seeing it somewhere and it makes sense to me. It's surprisingly hard to get your phases this high in a double boiler!)
As for how close the two phases should be - I would say no more than 10˚C apart, but I prefer 5˚C. So if you have your water phase at 75˚C, get your oil phase to 70˚C.
There is no easy way to figure out the melting point of a product other than watching when it melts. We can't figure it out because of confounding factors like the amount of oleic acid in the product. Check out this post for more information on that!
I just pour the oil phase into the water phase and start mixing then. I don't worry about how fast or slow I'm adding the oil - I just pour and then mix. Part of that is so I can see the awesome power of emulsification in action; the other part is that I am very klutzy and if I try to do more than one thing at a time, I will make a horrible mess. Mixing and pouring will not work for me!
Join me tomorrow when I share the first of some of my exciting experiments from the workshop with you! Woo!