On my Patreon feed, Jennifer asked: I saw (and like) the recipe you posted on the facial lotion (rosehip/calendula), and saw that you put the protein and panthenol in the hot water phase. Most of your earlier posts put these two in the cool down phase. Does it matter which phase?
It does and it doesn't: It all comes down to how the ingredient you're using can tolerate heat.
Quite some time ago - shortly after starting the blog, if I recall - I read a post on The Dish Forum by the mighty LabRat stating that hydrolyzed proteins should go into the heated water phase as they could handle heat. As well, they might be a vehicle for contamination, so heating them is a good idea. I altered my practice then, although there are still some hydrolyzed proteins I encounter that shouldn't be heated, so I put them in the cool down phase. I will make a point of mentioning they are not great in the heat when you see them in the future.
panthenol, the version I've been using - the liquid one - isn't heat stable, so it goes into the cool down phase. For my recipes from the HSCG conference, which was sponsored by the always lovely Jen from Lotioncrafter*, I've been using powdered panthenol, which is heat stable.
You may notice in the future that I'm adding dimethicone or cyclomethicone to a phase other than the cool down phase. This is because I'll be using different ones, and some of those can handle heat.
How do you know when to include an ingredient?