In the last post in the series, we figured out a simple castille soap recipe :
1 lb (543,6 g) of olive oil
2,0368 oz (57,74 g) of lye
3,0552 oz (86,61 g) of water
Now, we’re going to make this soap. First, using a digital scale, measure the olive oil in a large bowl as precisely as you can. You can buy pomace olive oil for this : it’s not very good for eating, but for soap it works just fine. Actually, it will be longer to stir the soap if you use high quality olive oil so I prefer to use pomace.
Again with the scale, measure the amount of lye in a small bowl. The water can be measured directly in your lye pitcher.
Add the lye to the water (NEVER add the water to the lye) in the pitcher. The lye will heat the water, wait until the solution is back at room temperature. Meanwhile, put the oil in a larger bowl if necessary. I mix my oils in a microwaveable bowl in case some of them needs to be melted, but it’s a bit too small to mix the lye.
When the lye has cooled down, pour the lye solution in the olive oil and mix.
And mix, and mix, until the soap mixture “traces”, or leaves traces in the mixture before disappearing. It’s a bit like doing whipped cream…
Pour the soap in the mold, and wait until it’s hard enough to unmold. It may take a few day depending on the temperature and humidity. I usually unmold while it’s slightly sticky, but holds its shape.
Let the cut soap dry for at least three weeks before using so it gets firm and mild. It may take longer depending on the heat and humidity in your home.