Rosin Gum

I did used a Rosin Gum from soap kitchen in my last batch 3 months ago. I melted it with my palm oil, coconut oil and some butters. I surprised that my CP soap last long in the bath and it didn't become mashed. I used the same formulation except I added a rosin Gum.

How much rosin did you use?

Sounds like your results are similar to me using bees wax.

Rosin reacts very quickly with lye -- similar to how stearic acid reacts if you've ever used that. Since you have to heat rosin fairly hot to melt it and the fast reaction generates even more heat, it's easy to get a volcano so don't drop your guard when using it in soap.

I added rosin at 15% to one of my standard recipes that already had good characteristics without rosin. I based my 15% on the info from the old soap making manuals I like to read. The soap with rosin was okay for general handwashing and the like, but I didn't think it was any better than the same recipe without rosin. I don't know that you'd want to go higher than about 20%, again based on the old manuals. I imagine using a few percent might add hardness to a recipe (similar to beeswax), but I personally wouldn't seek out rosin for that purpose -- my opinion is there are easier and less expensive ways to increase hardness and longevity.

In the 1800s, rosin was added to boost the detergency (cleansing power) of household and laundry soaps. It was a cheap filler that controlled the cost of the soap while keeping the cleansing power high. (It's not so cheap anymore.)

Rosin can be drying to the skin if used in a bath soap, but as always, your mileage may vary on that. It increases the transparency of liquid and "transparent" bar soap.

Thank you for sharing this, DeeAnna. Rosin is wonderful in CP. It is sensitizing but you can use as little as 1 oz in a 5-lb batch and notice a boost in lather. Here's some notes from my LS files...

ROSIN at 5%-15% makes incredibly clear light golden or dark amber brown LS with awesome lather. Try with 5% coconut oil and 80% liquid oil(s) of choice for high foaming shampoo.

Sold as fragrant, amber colored crystals, or in powder form, rosin can be purchased on line or at Dick Sports in the baseball department.

If you buy chunks, grind it to a fine powder to make it easier to melt. I use a cloth over a plastic bag and the side of a hammer to first make smaller particles, then run it in my (dedicated to soap) food processor. Wear gloves and a mask and avoid breathing the dust. Leave the lid on the food processor until the dust settles. I use A & H washing soda to clean my food processor. 1 tablespoon per 16 oz. hot water. Soak for 5 minutes. Should clean up fairly easily.

TO MAKE SOAP:

To calculate - Rosin has the same SAP value as Wheat Germ Oil.

ROSIN HAS A HIGH MELT TEMP. Weigh rosin into 4-cup Pyrex. Add some coconut oil from the recipe. (I use 2:1, CO:Rosin) Nuke 2-3 minutes @ high to 180°F (80°C). Add to other oils in the recipe. Be sure to mix in all the sappy bits on the bottom. Don’t let the temp drop below 180°F (80°C) to keep the rosin liquid. Continue to nuke oils @ 20 second intervals, if necessary, to get it completely liquid before combining with KOH solution.

NOTE: Pears, the very first transparent soap was formulated with castor oil and rosin some 200 hundred years ago. These 2 ingredients impart exceptional clarity to LS. Distilled from the oleoresin of pine trees, rosin saponifies much like an oil but WITHOUT any resulting GLYCERIN. It gives a smooth cold cream finish to the lather. It also acts as a detergent and preservative. May cause contact dermatitis in sensitive individuals.

"... Rosin is wonderful in CP...."

As I said in my first post, to each their own. I didn't think it was any better than the same recipe without rosin.

Thank you DeeAnn this is the first time I used rosin and I just used 10% but still a good result. I love the silky feel and the hardness of the soap.

Steve85569 said:

How much rosin did you use?

Sounds like your results are similar to me using bees wax.

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Hi Steve I just used 10% but I never use beeswax before. You need to grind it because isn't easy to melt. I learned my lesson.

If your rosin is in big chunks, then yes you'd want to break it up. Mine looks like small pebbles and sand. Be careful with melting -- a water bath is safest -- because rosin is combustible.

DeeAnna said:

If your rosin is in big chunks, then yes you'd want to break it up. Mine looks like small pebbles and sand. Be careful with melting -- a water bath is safest -- because rosin is combustible.

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Thank you very much DeeAnn I never know that. That's scary..

biarine said:

I did used a Rosin Gum from soap kitchen in my last batch 3 months ago. I melted it with my palm oil, coconut oil and some butters.

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I melt an oz of powdered rosin with an oz or two coconut oil ahead of time. Pour into 6 round cavity molds. Pop out when solid and store the rounds in a Zip-Loc bag in the freezer until ready to use.