Many people operate under the assumption that lye soap is exceedingly harsh, and that it doesn't compare in quality to soap that you can purchase from a store. The truth, however, is that almost all soap is made using lye at one point or another -- even Castile soap, which is gentle enough that many women choose to use it as the first soap for their babies. Soap-making kits can be purchased that use a glycerin-based solution that you pour into molds, letting it set. But the glycerin in these kits was most likely made using lye and oil, and it is generally cheaper to buy the ingredients and make your own soap from scratch than it is to purchase a kit.
In order to make your own soap, you're going to need around two pounds of olive oil or other oil, five ounces of lye, 12 ounces of distilled water and, if you want to make your soap extra smooth, about two ounces of beeswax. You may also choose to add around two ounces of scented oil as well as food coloring to match the scent. The mixing and stirring process will likely take an hour or more, depending upon your chosen oil. You can expect the drying time to last about two weeks, though that may vary slightly depending on the amount of ingredients used, the humidity and the temperature.
- Decide what type of oil you plan on using for the soap. Olive oil makes a very smooth, gentle soap, and is required for making Castile soap. Other types of vegetable oil produce different grades of smoothness and gentleness, whereas animal oils are generally not quite as smooth but tend to speed up the soap-making process. If you're looking for a more traditional soap-making experience, you should also keep in mind that animal oils were used for centuries while making soap.
- Heat the oil to around 110 degrees. If you're using it, add the beeswax at this point and let it melt. Set aside, but maintain the temperature.
- Wearing safety glasses, slowly begin adding your lye to the distilled water. The water will begin to heat, and you need to let it cool to around the same temperature as the oil (110 degrees).
- Once the temperatures are around the same, slowly add the lye water to the oil. Take care when doing this to avoid splashing.
- Stir the two components together until you can see "traces," or spoon-lines in the mixture that remain for a few seconds.
- Add any fragrances or coloring to the mixture, making sure not to use too much -- you don't want to overdo it.
- Pour the soap mixture into molds, or into a pan lined with wax or parchment paper. Cover with a towel and set someplace out of direct sunlight for up to two weeks.
- Once the soap has had a chance to solidify and get rid of its excess moisture, you may remove it from the molds or cut up the larger block produced by the pan. Wrap it loosely in a towel or other cloth and let it sit for a bit longer; it can be used once dry, and generally keeps for quite some time.
- The amount of soap that is made using this recipe will vary depending upon whether you use molds or cut the soap into blocks, but generally you will be able to create between 16 and 24 pieces of soap. To modify the amount of soap made, be sure to keep the ratio of oil and lye equal. The other ingredients can vary in amounts, but varying the ratio of oil to lye can cause the soap to become harsh or to not set up.