In this post, Creating products: A moment or two about recipes, Caroline said, I like using weight measurement for recipes because it is so much easier to measure than worrying about cups/teaspoons, etc. and also find it more convenient. However, there are a lot of recipes out there that don't use weight. This one particular recipe did use the 1/3 rule in that it asked for 1/4 cup shea butter, 1/4 cup coconut oil and 1/4 cup beeswax pastilles. I decided to weigh them and found that the shea butter weighed 44 gr, the coconut oil 54 gr and the beeswax (I used freshly grated, packed) 18 gr. So obviously, for a more accurate recipe, weight does make a difference since the density of the ingredients has a bearing on the end result. Is this correct or am I missing something"
You are completely correct! If you were to make the recipe you mention as a lotion bar, you'd have a sloppy mess as you only have 15.5% beeswax to harden the bar, versus the 30% we'd normally use.

To see what I did here - 44 grams shea butter + 54 grams cocont oil + 18 grams beeswax = 116 grams. I divided each thing by 116 grams to get the percentage. 18 grams beeswax/116 grams total = 15.5% rounded down slightly. Check out this post on how to figure out the percentages. 

This is how I generally explain it. If I say to use 1/4 cup cocoa butter, is that before or after I've melted it" Is that cocoa butter in pastilles, shards, or almost a fine powder" Measuring by volume i...