navigator9
Well-Known Member
"Has anyone tried to divide the water in half, dissolve the lye in half of the water and the salt in the other half, separately. Then mix the two waters together? ..."
You can only make a brine that is about 26% by weight of salt at room temperature. You can make a lye solution up to about 50% NaOH. If you split the water in half, you might not be able to dissolve as much salt as you might want. On the other hand, I don't think there would be a problem with getting the lye dissolved with this method -- people take this approach when making milk soap, for example.
For those who use seawater for this type of soap, keep in mind that the average salt content of seawater is only 3.5%. That's way, way below the saturation limit -- quite different than those who want a 25% brine.
I'm starting to get lost in the math. Never my strong suit. Wikianswers says that "100 grams pure water can hold about 38 grams of sodium chloride. " So here were my calculations for tomorrow's batch. My recipe uses 340 g of water, 135g of lye, and 85g of salt. From what I've read, I should be able to dissolve 135g of lye in an equal weight of water. So that would leave me with 205g of water left over to dissolve 85g of salt, and I could hopefully get 76g (and a bit) of salt to dissolve. Do you see any glaring problems with my calculations? I really want to make this recipe with the full amount of salt. If I didn't have to go in to work today, I'd try it now, but I don't want to rush. Besides, my individual molds are full. Now, I'm going to be thinking about this all day at work! Another reason why I can't wait to retire.....more time to soap!