Unusual transparent soap

Soapmaking Forum

Help Support Soapmaking Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Joined
Apr 11, 2015
Messages
1,183
Reaction score
1,434
Location
New York City
This is classic transparent soap with the interesting twist that it incorporates rosin, which is a type of pine tree ooze (chunks of which are shown at the upper right of the photo). Viol players know it as the stuff you put on your bow.

Rosin is meltable and saponifiable and was once an extremely common ingredient in commercial soap. The rosin provides all the color and aroma for this soap. I was trying to think of how to describe the fragrance to you but it's difficult. Maybe earthy with a touch of caramel sweetness.

IMG_20170114_174052.jpg
 
Wow....nice job TOMH! I'm just wondering if that was the scent in Neutrogena glycerin soap from 50 years ago.Care to walk us through the process? Many thanks for all your sharing...

I used to use that soap. :)

TOHM, they are beautiful soaps. Your dedication to creating transparent soap is amazing to me. I tried once and it was so very much work and so very complicated, and unsuccessful, that I have not tried again.
 
Wow....nice job TOMH! I'm just wondering if that was the scent in Neutrogena glycerin soap from 50 years ago.Care to walk us through the process? Many thanks for all your sharing...

I don't think Neutrogena was a rosin soap, though it had that color. Below is a link to the original patent for a type of soap the inventor described as "neutrogenous" that was given the name Neutrogena. It was made with coconut oil, tallow, castor oil and TEA (see below).

The patent describes how the high pH of plain sodium soap causes damage to skin proteins. By using a substance called triethanolamine (TEA) he was able to create a soap with essentially a neutral pH (7.5 in 10% solution). I assume that has something to do with the name.

Note that original Neutrogena was a hard soap made from 30% castor oil, which kinda of highlights that it's questionable to indoctrinate every newbie into the group beliefs about how to formulate soap.

https://www.google.com/patents/US2820768

As for how I made this particular soap, you can learn about it in Catherine Failor's Making Transparent Soap book. You have to be careful and confident to use this particular method because it requires 95% ethanol or denatured alcohol. It's hard to keep it from boiling off, and it's highly flammable. I would personally never do it on a gas stove.

There's a lot of history behind the technique. Failor is actually adapting methods for crafters that have been known for maybe 200 years or more. It was worked out long ago that alcohol, glycerin, sugar and castor oil can be used as solvents and crystal modifiers to dissolve soap into liquid solution and have it remain transparent when it solidifies.

Rosin is also a crystal modifier that helps clarify soap, which is why this recipe does not include castor oil.

Fabulous -- love that rich transparency!

Is your recipe similar to lsg's?

Thanks!

Yes and no. Glycerin is a good solvent for this purpose and can be used for any kind of transparent soap, including M&P base. However, these types of soaps aren't really made with only glycerin because that produces soap with some flaws, very notably that it sweats really easily. So normally transparent recipes use a combination of solvents that work well in unison. This one uses ethanol, glycerol, and sugar.

The M&P base I've been making uses a different combination of solvents: propylene glycol, glycerin and sorbitol.

I used to use that soap. :)

TOHM, they are beautiful soaps. Your dedication to creating transparent soap is amazing to me. I tried once and it was so very much work and so very complicated, and unsuccessful, that I have not tried again.

Thanks very much. Sometimes there's renewed excitement going down a road you haven't explored before. I haven't actually even gotten that far. I wanted to make sure I could execute some proven techniques and recipes more than once, and this soap is part of that. I have more adventurous transparent soap possibilities I want to try as time allows.
 
Very interesting color that is. Though I've never used Pear's soap ( old or new formula) , but I'm intrigued by the scent description. Earthy and caramel... Mmm... ;)
 
I love the scent of rosin! TOMH, thanks for posting your gorgeous soap. I had never heard of rosin in soap before, so of course I've been looking for info all over the internet, and I've learned so much about the history of soap in the process. Thank you!
 
Back
Top