Hello
I am not the most experienced soap maker, but until one comes along I will give you my two cents worth!
First of all, since you are new to soapmaking, I am going to suggest that you NOT use beeswax or honey. Both are extremely difficult to work with and cause overheating. Milk soaps can also be very tricky, but I can tell you what I know about using it.
As intimidating as it can be at first,
lye calculators are your friend! Soap calc has a very good "how to use" page here
http://www.soapcalc.net/info/helptext.asp Just play around with different things until you get a bit more comfortable with it. You will be surprised at how much you learn just by taking the time. Good (and safe!) soapmaking requires taking your time and getting comfortable with what you are trying to do, there are no shortcuts.
Since your son has a sensitivity to coconut products, a good alternative is palm kernel oil (not the same as palm oil) or babassu oil. Both are very bubbly/cleansing. If you plan to try coconut oil anyway (and I have no idea how sensitive he is or if using it in soap would be a problem or not, up to you) I would say keep your percent low.
As for the goat milk, are you using fresh (or refrigerated), canned condensed, or powdered? The split method is probably the easiest, where you divide your total water for your batch in half and use one half of the water for your lye and the other half you replace with milk and add it directly to your oils. If you search for split method on this forum you will find a lot of info. If you want to use 100% goat milk for your liquid (and again, I don't recommend that for a beginner), freeze it first and add your lye to the frozen chunks very very slowly a little at a time. If it gets too hot it will turn orange and stink to high heaven but if that does happen don't worry, it still makes perfectly good soap and it won't stink when it's all done.
I would not start with a 4 or 5 lb batch, I would start smaller, say 2 lbs. Things can go sideways and until you have a few batches under your belt and a recipe you are comfortable with it's better to start small. The way you figure out how much oil to use for your mold is W x H x L = Volume, Volume x 0.40 = total oils. I know that can sound confusing, but first you measure the volume of the mold. I will use mine as an example. My mold is 8 inches by 3.5 inches by 2.75 inches, so 8 x 3.5 x 2.75 = 77 (my mold is 77 cubic inches volume). Now I want to know how much oil I need to use for my soap, so 77 x 0.40 (the amount of oil I need is a constant, I don't know why) = 30.8 ounces of oil. So I will use 31 and have a small container ready for any extra.
Now on to a recipe! There are a lot of good recipes posted on this forum, but you should always run ANY recipe through a
lye calculator. Sometimes the information on the internet is wrong, and anyone can make a typo entering it, so always always ALWAYS check!
Based on the ingredients you want to use, I would do something like this:
Olive Oil 40%
Palm Oil 40%
Coconut (or PKO) 15%
Castor Oil 5%
50/50 goat milk/water
When you enter this into soapcalc you will see the cleansing isn't very high, but it is still soap and will work just like soap but be gentle. If you want it to be even milder you could increase the Olive oil to 50% and decrease the palm oil to 30%. Play with soapcalc until you have the properties you want! I like a milder conditioning bar, my husband (whose skin is not as dry as mine) likes more cleansing.
Whew! That was a long answer! Hope this helps
Good luck and be sure you keep us all posted on how it comes out. Someone is always around if you have more questions.
