Rosin soap

[Pears]

Hello, I'm new here, happy new year. I'd like to make some rosin soap but I've read that it's better to make the sodium rosinate first and then add it to the soap. I have a couple of old recipes for making sodium rosinate but they are very vague and probably not reliable. How would you quantify how much sodium hydroxide is in a quart or gallon of "strong lye" after all? If anyone has a more contemporary recipe or guideline, I'd really appreciate it. I'll paste the old recipes that I have below. Thanks.

Soap Without Grease.--To four gallons of strong lye add ten pounds of distilled rosin, or eight pounds of pine gum, not distilled and free from trash is better; boil steadily until there is no rosin to be seen, and if the quantity of lye is not sufficient add more, and continue to add until the rosin is out, and boil until it makes a brown jelly soap. I have used this soap for a year, and it is equal to the best soap made with grease.

To eight quarts of strong lye, add three pints of pine gum or three pounds of rosin; boil for five or six hours, stirring well to keep the fluid from burning at the bottom. A little wheat flour added will make it hard, if desired.

Rosin added in the soap must not be more than 33%. One secret to adding rosin is to make the tallow soap first before adding the rosin soap in it. This will result in a better quality of soap.

 

[Lindy]

Rosin is Pine Tar which is available at any farm supply store. I make Pine Tar soaps and I recommend that you keep your %age down to no more than 5%. I add it to my hard oils & butters to melt down, then add my soft oils and away I go. Because of our modern methods we don't have to give it any special treatment.

I haven't heard of anyone making a 100% rosin soap, but that doesn't mean it can't be done.

 

[Pears]

Hi Lindy, thankyou for the reply. I believe that rosin and pine tar both contain the saponifiable resin acids. I know that rosin is a byproduct of distilling turpentine from pine resin and pine tar is made by heating the pine wood itself. I think you're right about keeping the percentage in the soap quite low. Pure sodium rosinate is a viscous liquid, so too much would soften the end soap. I've just found an interesting article, which states that no more than 15% rosin should be added.

http://www.scribd.com/doc/53151356/38/TALLOW-ROSIN-SOAPS

I'd like to make a transparent soap with a small amount of rosin but I'm new to transparent soap making so I might first try to make pure sodium rosinate and just add it to some melt and pour soap. The article mentions "12 gallons of lye of 30B. are needed for every 100 lbs. of rosin". Can anyone tell me how much sodium hydroxide to add to water to make 30B (30 bome?). Maybe someone has a more contemporary guideline. Thanks.

 

[Lindy]

That is fascinating! Thank you for the link - I have downloaded it to read over time.

I would love to find a source for the lighter "rosin"....

I wish I could help more.....

 

[Pears]

I'm glad you found it interesting. The reason that I thought that 30B meant 30 bome is because I found some old rosin soap recipes that mentioned using 38 bome. I'll link them below. I now believe that bome is simply an old term for the weight for weight percentage of the solution, as most lye solutions used in soap making are somewhere around 30%.

If "12 gallons of lye of 30B. are needed for every 100 lbs. of rosin", I calculate that if it's imperial gallons (4.5L), for 1 liter of 30% lye solution, 833 grams of rosin are needed. If it's US gallons then for 1 liter of 30% lye, exactly 1kg of rosin is needed. I'm guessing that it would be better to go with the higher amount of rosin as a precaution, as you would when superfatting a regular soap.

http://www.lformula.com/index.php?part=him001&page=017
http://www.lformula.com/index.php?part=him001&page=011

 

[Lindy]

What country does that site originate from do you know? I saw in the top right that it has been translated to English....

 

[Pears]

It's a russian site.

http://www.lformula.ru/index.php?part=him001&page=011

I now know that the proper translation is Baumé. According to the book I linked to before "There are 23- lbs. of caustic soda wanted for making 10 gallons of lye of 30 degrees Baume."

http://www.scribd.com/doc/53151356/Make-Soap-and-Candles#page=40

So for the 12 gallons of 30B lye called for in the rosin soap recipe, 27.6 lbs of sodium hydroxide would be needed. That equates to 276 grams of sodium hydroxide per liter of lye, which is exactly enough for 1kg of rosin. Or 833g of rosin, if it was imperial gallons and not US gallons.

 

[Lindy]

Yeah I figured the measurements would be imperial due to the nature of the recipe and stuff. Have you located a source for the rosin yet?

 

[Pears]

There are lots of sources on ebay but it helps to type in colophony instead of rosin, to avoid all of the violin rosin being offered on there. You can also buy it in powder form, to save having to crush it up yourself. Pears soap use to be a dark amber color, suggesting that the rosin used was quite dark to begin with. Being a fan of the old Pears soap, I'd prefer to make a fairly dark amber soap. Here's an interesting piece...

Rosin varies in color, according to the age of the tree from which the turpentine is drawn and the degree of heat applied in distillation, from an opaque, almost pitch-black substance through grades of brown and yellow to an almost perfectly transparent colorless glassy mass. The commercial grades are numerous, ranging by letters from A, the darkest, to N, extra pale, superior to which are W, window glass, and WW, water white varieties, the latter having about three times the value of the common qualities.

 

[Lindy]

Wow! I use the almost pitch-black stuff. Going looking...

By the way - thank you! Some great information came to light in this thread. Well done!

 

[Pears]

Thanks, I try to be thorough in my research. Rosin can be black but it's usually dark to light amber in color. I think that yours might be pitch black because it's pine tar.

You might like to read the preface of that book. It reveals that the author and his contemporaries were from the US. It's therefore fairly safe to assume that the measurements were in US gallons, as it had been the standard measurement in the US since the early 19th century. The book was written in the late 19th century.

http://www.scribd.com/doc/53151356/Make-Soap-and-Candles#page=7

 

[Lindy]

Thanks - mine is a greeny brown black and the soap I make with it is dark brown...

 

[Pears]

I've tried grandpa's wonder pine tar soap before, which sounds similar to yours. Have you tried rosin soap before? I've edited my last post, to include some more info on the measurements.

 

[Lindy]

I've not - I don't even know anyone who makes it. Sounds fascinating though.

 

[Birdie Wife]

This has got me really interested now. I'm planning a range of soaps using ingredients I've gathered myself in the Scottish Highlands, and pine tar from Scots pine sounds like a quite involved process. However, if I can use the resin in its natural form then that's much easier. I love Pears soaps

Anyone know if a pine resin soap differs greatly from a pine tar soap, apart from the colour?

 

[Pears]

Hi Birdie, I used to love Pears soap too but they reformulated it in 2009 and it's now a shadow of it's former self. Which is why I'm interested in making my own rosin soap. I'm also trying to develop a Pears type aroma to add to the soap. I think that I've narrowed it down to about five essential oils that are required but I'm still working on the ratios.

The main difference between rosin soap and pine tar soap, aside from the colour, is the smell. Pine tar has a smokey aroma and rosin has a warm, amber, piney smell. If you're using crude pine resin instead of rosin, then it should smell somewhere between rosin and real turpentine. Real turpentine is slightly piney and fruity, unlike mineral turpentine. Rosin does add to the overall smell of Pears soap. I've tried rosin soap scented with coal tar before and although it smelt of coal tar up close, I could catch a faint smell similar to Pears soap from across the room.

As it happens, there's a company in Scotland called Spirited Soaps that sell a whiskey and pine resin soap. They call it "Earth". It's quite expensive but you might like to get a single bar for testing against your own creations. I would give you a link but I'm not sure that it's allowed.

 

[Lindy]

Birdie you need to check with your safety assessor because it is my understanding this ingredient is not allowed in the EU....

 

[Pears]

I know that coal tar isn't allowed in the EU, accept in licensed pharmaceutical shampoos but I think that pine tar and rosin are allowed.

 

[Lindy]

Actually Pine Tar is not allowed either....

 

[Pears]

I think that it may just be that only pharmaceutical grade pine tar is allowed. Christina May Pine Tar Soap and Shampoo are made in England.

Our pine tar soap contains 2% Pharmaceutical grade pine tar (PINE TAR BP) in a pure triple milled vegetable soap base enriched with Vit E. The bar is hard and very long lasting with a good white lather.

Pine Tar is an effective germicide and fungicide and is a traditional remedy for all sorts of skin problems.

Many people rely on pine tar soap to relieve the symptoms of various skin complaints including acne, psoriasis, eczema and acne.

Pine tar soap is the nearest equivalent to coal tar soap which is now illegal in the EU. Any soap that is sold as coal tar soap does not actually contain any coal tar as coal tar is now banned in any over the shelf product.

I think that the rules are much looser regarding the use of rosin. I know of three UK companies that manufacture rosin soap and another one that is currently testing a rosin soap for retail. They happened to send me a sample.