Why Does Ivory Soap Float?

In 1879, when Ivory soap was first developed by Procter and Gamble, it sank just like any other brand. It had never entered anyone’s head to make it float.

The soap’s “floatability” actually came about by accident.

According to Procter and Gamble, one day, in the early days of Ivory soap manufacture, a worker went off to lunch, forgetting to turn off the machine that mixed the solution of soap.

When he returned, he discovered a curious frothy mixture.

Various workers and undoubtedly Mr. Procter himself took a look at the bubbly concoction and decided it was still usable, there was no need to throw it all away.

Not long after the soap hit the market, the manufacturer started receiving letters from excited consumers asking for more “floating soap.” The idea was novel, and the floating soap certainly had its uses, especially if one had to bathe in the nearby muddy Ohio River.

Once the company traced the floating soap to the frothy solution, it realized all it need do was to beat air into the mixture as it was being made. This made the soap lighter than water so that it would float.

And that’s exactly what Procter and Gamble does with Ivory soap today, though some consumer advocates point out that this technique gives less soap for the dollar.