There is a few of ways you can avoid scorching your milk.
1. You can use half milk and half water in your recipe. By desolving the lye in the water first (in a very well ventilated area, or under a stove fan), in a glass, stainless steel, or plastic bowl, you can wait for it to cool down to below 80 degrees or less, then add the goats milk.
2.You can put your chilled milk in a glass, stainless steel, or plastic bowl into an ice bath. Then slowly, ever so slowly (like over a half hour period), add your lye while stirring continuely. This way the temperature of the lye hitting the goats milk is kept down so your milk will not scorch.
3. You can freeze your goats milk (in ice cube trays) and just put the amount of milk you need in a glass, stainless steel, or plastic bowl, then add your lye over the cubes, a small amount at a time (or whole amount, doesn't matter, just make sure there are NO clumps of lye not desolved) and stir continually until the lye, along with the milk is desolved. There are no fumes (or very little anyway) with this method, so there is no need for ventilation.
* It is best to strain your lye, in a stainless steel strainer,
or plastic mess strainer, into your oils because of fat molecules that will congeal in the lye and will make unwanted spots in your finished soap.
There are also three ways to let your soap cure when goats milk is used.
1. You can insulate your soap (by covering it with a blanket) and let it heat up to the 'gel stage'. The 'gel stage' is an early phase to *saponification process, when the soap becomes a warm transparent gel and slowly returns to being opaque, slightly more solid, and cooler. The color of your soap often deepens during this method.
2. You can let your mould sit, uncovered, at room temperature, until the next day when it will be time to take it out of the mould. Your soap may or may not go thought a gel stage during this time. Or some of the soap may gel, and parts would not have, which would leave parts of your soap looking a bit darker from the entire batch. There is absolutely nothing wrong with this, it is just a matter of opinion on how you want your soap to look.
This is a milk soap that I left uncovered, at room temperature, until the next day. The dark part of this Goat Milk soap is natural. The lighter parts have titanium dioxide in it to lighten the color.
3. You can also stop your soap from gelling by putting it in you refrigerator for a few hours (or freezer). The cold will keep the temperatures down so it will not heat up to the point of gelling. The color of your soap will not darken as much this way.
This is a milk soap I put in the refrigerator so it would not gel. The very bottom part of the soap is natural, while the other parts have titanium dioxide or a brown mica for color. Can you see the difference in the natural shade color part of the soap I left out and this one I had in the refrigerator? Definitely lighter.
4 . Another thing you can do is put your soap, mould and all (providing it is oven safe) into a 160 degree oven for 1-3 hours, then Shut your oven off, and without opening the door, let it stay there for 24 hours. It will come to gel pretty fast. The color of you soap can come out a deeper color during this phase also.
This goat soap I put in the over at 160 degrees for 1 hour, and left the door closed over night. The color, although it was the same shade when poured as the first two soaps in the beginning, darkened up quite a bit during the forced gel in the oven.
* * "Saponification" refers to the chemical reaction between fat and lye that results in the formation of glycerin and soap.
It will NOT BE fat and lye anymore, but.....soap!