For 8 weeks in October through December, I shared my office at the Technion with Sergio, an optical physicist from Spain, who was here collaborating on a project on adjustable eyeglass lenses. (Cool, right?)

Sergio makes all his own soap and the night before he left Haifa, he invited his host Koby and us to see how it’s done. Koby found him a kilogram of NaOH (aka caustic soda or lye) and a very accurate kitchen scale. Sergio provided water and canola oil, as well as some bits of pine needles for scent. He had a book with tables of the relative amounts of all ingredients, which Koby and I, as the mathematicians, were expected to compute in our heads. We all had to stand back while he dissolved the lye in the water water, and then used a wooden spoon and electric mixer to combine with the oil.

Then, wait two days for it to harden, and another month for the soapmaking reaction to complete.  I brought the soap back to the office to cure.  After a day or two it remained liquid, and now, three weeks later, some of the bars are still liquid, and some are half-solidified, although the top solidified first, and then buckled.  Sergio believes that the problem stems from his use of liquid oil instead of wax or animal fat, which would harden at room temperature.

Here’s some pictures of the process:

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When we got back from the trip to Istanbul, I had a new officemate, who found 7 little molds filled with a gelatinous liquid mixed with pine needles on his desk.  Fortunately he took this in stride.  Now I just have to wait a few more weeks for the soap to be ready so I can start showering again.