Besides the term superfat, you'll also hear of its close cousin, 'lye discount'. I mention it because they are often used interchangeably (because the resulting outcome is the same), but they are each approached differently:
From our "Acronym' thread:
Superfatting: The practice of adding extra oil/fat to ones soap batter either during trace in CP, or after the cook in HP than is needed to react 1:1 with the lye. This is done to provide a safety cushion of fat/oil in order to prevent lye-heaviness in the finished soap. Basically the same as 'lye-discounting', but different in approach (see 'Lye Discount' for details).
Lye discounting: The practice of using less lye than is needed in which to saponify all the oils/fats in one's formula 1:1. This is done to provide a safety cushion of fat/oil in order to prevent lye-heaviness in the finished soap. Lye Discounting is basically the same concept as 'superfatting', but technically different in how it is approached. With 'lye discounting' one decreases their lye amount by a certain percentage of their own choice in their 'up-front' calculations, and with super-fatting, one adds a certain percentage of oil/fat of their own choice directly to the pot either at trace in CP, or after the cook in HP.
You can use any oil of your choosing for a superfat. It's completely up to you. I personally don't superfat my bar soaps in the technical sense as defined above, but rather do an up-front lye-discount. It's easier that way and I've found the results to be the same in my finished soap. On
soap calculators such as SopapCalc you'll see a box for Superfat %. They have a default of 5% in the box to insure against lye-heaviness, but you can change it to a different % depending on your preferences. Sometimes I use 5%, sometimes 8%, sometimes 13%, sometimes 20%, depending on my recipe. Even though the SoapCalc box says "Superfat %", it's technically a lye discount, because everything is calculated up front and you'll be combining all the oils together in your soap pot before adding the lye solution.
Regarding question #2- it sounds more like a problem with the actual oil/fat formulation, rather than with the goatmilk itself. I make goatmilk CP and also coconut milk CP as part of my regular repertoire, and both are as hard as my formulas without them included. What kind of ingredients are on the ingredient list of the soap in question?
In regards to making goat milk CP, I find it very easy to do via the 'split method':
I mix my NaoH with an equal amount of water in weight, then for the needed remainder of my total liquid amount, I use fresh goat milk (which I add to my oils before adding in my lye solution). That will give me about a 30% milk soap. If I want to do a 100% full-milk soap with the split method, I proceed the same way, but I fortify my fresh goat milk portion with enough powdered goat milk to bring it up to an equivalent concentration of a full-milk soap, and add it to the oils before adding in the lye solution.
IrishLass
