Saponification is the process of making soap. When an oil/fatty acid such as olive oil, mixed with a base (such as lye), and heated up, two products are made. One of the two products made from that mixture is fatty acid salt, or soap as it's commonly identified as. The second is glycerol which has a low toxicity. During the saponification process, the mixture has an acidity, which tells that it's not safe for usage. After the saponification process is complete, the pH should be a base.