Title: Saponification Chart 1
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Don't confuse the numbers in this chart with normal saponification values that require complicated equations to calculate the amount of lye to saponify fats.

In this chart, the math has been done for you. All you have to do is multiply the number of ounces (or grams) fat you would like to use, times the number in the chart. The answer is the number of ounces (or grams) lye (sodium hydroxide) required to saponify that much fat.

Nothing is "exact" in science. These numbers are based on the "average saponification value" of particular oils. For instance, the saponification value of macadameia ranges from .193 to .198, depending on the source of the oil and how it's refined. These values also don't allow for the fact that technical grade lye is 97% pure.

Use these exact numbers and your soap will contain a bit of excess fat, yet they will never contain too much lye. It's good to calculate the lye as closely as possible. If you want soap even more superfatted, add measured amounts of excess fat.

Inventing soap recipes is quite an art. Some fats tolerate more excess fat in soap than others. The more saturated fats tolerate more superfatting and result in soap that traces and hardens more quickly.

I like to use saturated fats for at least 1/4 of the total fat in a recipe. Saturated fats include: coconut oil, babassu oil, palm kernal oil, beef tallow, palm oil and lard.

Beeswax, bayberry wax and carnauba can be added to soap mixtures (no more than 1 ounce per pound fat) and the amount lye is .07 oz lye per oz wax.

Note that, petroleum jelly, glycerin and mineral oil do not react with lye. You can add these to soap as superfatting agents without increasing the amount of lye for the soap recipe.

Using potassium hydroxide instead of sodium hydroxide: I received many questions about substituting the types of lye. I've made a few test batches of soap with potassium hydroxide and it definitely stays soft much longer, but eventually hardened the same as if sodium hydroxide was used. In case you want to know the amount of potassium hydroxide to use in a soap recipe, go ahead and calculate the amount of sodium hydroxide required. Multiply the number of sodium hydroxide by 56 and divide the answer by 40 to equal the amount potassium hydroxide required (more potassium than sodium). Be aware that potassium hydroxide reacts more violently when added to water than does sodium hydroxide. Allow plenty of room in the container for possible "boiling up."

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