When I was a kid, I had a bar of Fuzzy Wuzzy soap, a soap that grows hair (yeah, no kidding). There is a good blogpost by Randy Blazenhoff. Randy’s blog includes a video of the Fuzzy Wuzzy commercial which hooked my mom into buying the soap. After the soap is all used up with frequent bathing, there is a small toy in the middle. In the above commercial, the boy got a whistle which would have been a good toy. I got miniature plastic dentures. The soap was originally made by the Aerosol Corporation, but they stopped manufacturing it a long time ago. A few years ago, the trademark was revived by Crazy Foam International and sold in a slightly different shape and package. I was able to purchase some of their soap on the internet. The new soap has the same weird smell as the old soap which I will describe as chicken fat mixed with apples. The new soap grows hair that looks just like the old soap, but I was disappointed that it does not have a prize in the center.
Many people on the internet have guessed what makes the hair. I always thought it must be crystals that grow like “Magic Rocks.” (See this blogpost.) Some people online speculated that it was a fungus. When my soap grew hair, I scraped some of the hair onto a microscope slide and was surprised to see that it was a type of fungus with a mixture of hyphae and spores.
After I washed all of the hair off and had used the soap a few times, I let it dry out again and more hair grew though not as much as the initial hair.
I also scraped some of the white “hairs” onto a petri-dish containing fungal culture medium and the fungus grew.
I looked at the fungus under a microscope with one of the lab microbiology techs and decided it was a Cladosporium species. Cladosporium is a common household mold which can be associated with allergies and asthma. Here is a blogpost about Cladosporium which has a photo of the mold growing in a home, and you can see the white “hair” projecting up from the mold colony. I was delighted to see that the blogpost was medically reviewed by Judith Marcin, M.D. who is a Hamline MFAC graduate like myself. I couldn’t find any Fuzzy Wuzzy soap for sale at the time of this blogpost but I do have a few boxes of it so if a kid wanted to do a science experiment and replicate my results, contact me. Probably best not to bathe with it, though. I’m curious to know how many people who used the soap as children have asthma/eczema or other allergic conditions which is another possible science project.