This post will walk though the basic process I use to craft my own soap. I will post separately about formulating soap–this is about the crafting.

My favorite current formula I have named “praise the lard.” You may have guessed that it has a good proportion of lard in it. Lard is low cost and contributes some very favorable qualities to the bar.

I make a “two pound” batch, which really means two pounds of oils. Here’s the recipe:

ingredient quantity
lard 18 oz.
olive oil 13 oz.
coconut oil 3 oz.
lye (NaOH) 4.35 oz.
water 12.2 oz.
fragrance oil 1 oz.

I do “cold process” soap making. I’m not providing heat to the process, so saponification happens relatively slowly. This affords me time to work with the ingredients and gives a smoother textured bar of soap than hot process.

I use five pound yogurt tubs to mix my oils in. The coconut oil and lard are solid at room temperatures (they are saturated fats). I use an ice cream disher (scoop) to remove and weigh the right amount of oils from my buckets. A kitchen scale is accurate enough to weigh these amounts, for one important reason. This amount of lye is discounted slightly to give a finished bar that contains a small amount (5%) of unreacted oil. I’ve got real gripes about the precision of household scales, but that’s another post.

I warm my oils for about a minute in the microwave oven. This gets them to about 110 degrees F, which melts it all together. For efficiency’s sake, I am in the habit of weighing up several containers worth of oils and storing them with lids ready to grab when I want to make some soap.

I use the scale to get 12.2 oz of distilled water, then I weigh up the lye in a separate glass bowl. Dissolving the lye in the water generates some nasty fumes as well as heat, so I take things out to the garage for this step. Do not add water to lye, always add lye to water. The solution we are making is strong enough to burn you. You should probably wear gloves.

When the lye is fully dissolved, I add it to the oils in the yogurt tub. The size of these tubs is close to ideal, with the mix filling the container about two thirds full.

I have a stick blender I purchased at a yard sale that I use to emulsify the oils and lye water. This emulsion is important to the reaction. Different oils react at different speeds. My mix takes about 15-20 minutes to reach the state called “trace” which is a persistent emulsion that looks like pudding. I don’t mix continuously.

Once the mixture achieves trace, I add my fragrance oil. If you add colors (I don’t) they go in now as well. Then mix everything together and pour into a mold.

I crafted my mold (of course) from some scrap plywood. Even though I standardized on two-pound batches a while ago, my mold has the ability to place the ends for a bigger or smaller batch. I line my mold with freezer paper.

I smooth the top out with the spatula that I use to scrape the mix out of the yogurt bucket. After 24 hours or so the soap has set up enough to pull the loaf out of the mold, but I leave it in the paper for another day.

After soap has firmed up a couple days, I slice one-inch thick bars from the loaf. Soap you craft has to cure for six to eight weeks to be it’s best. You have soap the day you cut the bars, but it performs much better when you let the moisture work its way out of the finished bars. Some people weigh the soap to determine when it’s done, but I just wait eight weeks.