What is the Zap Test?
The zap test, or zap tongue test is a quick little way to figure out if your soap has leftover unreacted lye in it. Simply lick your finger, rub your soap, and place said finger back on your tongue. If you feel a “zap” your soap is lye heavy and will need to be rebatched. It is vitally important that you check, double check, and triple check your recipes ingredients to make sure that you have enough lye to saponify only the amount of oils you are adding and not any extra. This could result in a soap that is caustic and could be potentially harmful to whoever uses it. For this reason we recommend you using a soap calculator, which makes it much easier to determine if your recipe is on the money, or needs to be restructured.
