Rosin

[Pears]

The rosin from Diamondgforestproducts is produced from Pinus elliottii var elliottii (Slash pine). I've tried it and it's okay but it doesn't produce that deep aroma in the soap, which you might prefer. It's on the lighter, fresher side, which may or may not be what you're after. Historically, it was the rosin from Pinus palustris (Longleaf pine) that was used for soap making, which produced a deep, clean, woody aroma in the soap. You may like to read the excerpts below:

The Edinburgh New Dispensatory (1830)

"P. palustris Ait.- Missisippi pine....Product: Boston turpentine;....resin for making soap, and the best tar for cordage."

http://books.google.co.uk/books?id=...wbE0IHACw&ved=0CDEQ6AEwAQ#v=onepage&q&f=false


The Encyclopaedia of Geography (1839)

"It (Pinus palustris) is preferred to every other species of Pine, even in England, and is put to a great variety of uses both in civil and naval architecture....The United States are entirely dependent on this tree for the resinous matter so indispensable in ship-building; and which at present is obtained principally from the lower part of North Carolina. Forty thousand barrels were exported to Liverpool (England) alone in 1805, and it is besides sent to France, and makes it's appearance at Paris under the name of Boston turpentine."

http://books.google.co.uk/books?id=IHFBOi0JiDUC&pg=PA422&lpg=PA422&dq=boston+turpentine+pinus&source=bl&ots=gpZ6TtpkMO&sig=gC0YjUvJmzNKgXkMXCnobb8y_Qs&hl=en&sa=X&ei=Q3xyUovdCsHaswbE0IHACw&ved=0CEkQ6AEwBw#v=onepage&q=boston%20turpentine%20pinus&f=false


A Treatise on the Manufacture of Soap and Candles, Lubricants and Glycerin (1895)

"American rosin is characterised by a peculiarly fragrant smell, in which French rosin is deficient, and this smell is retained by the soap made from the rosin. During the American civil war, when no rosin was to be had from thence, the small stores of it in England were so much valued for this fragrance in soap that soapmakers were compelled to pay more for American rosin than for tallow."

https://archive.org/stream/atreatiseonmanu00wilsgoog#page/n86/mode/2up


The Handbook of Soap Manufacture (1908.)

"Rosin is the residuum remaining after distillation of spirits of turpentine from the crude oleo-resin exuded by several species of the pine, which abound in America, particularly in North Carolina, and also flourish in France and Spain. The gigantic forests of the United States consist principally of the long-leaved pine, Pinus palustris (Australis), whilst the French and Spanish oleo-resin is chiefly obtained from Pinus pinaster, which is largely cultivated....

The American variety possesses a characteristic aromatic odour, which is lacking in those from France and Spain."

http://archive.org/stream/handbookofsoapma004247mbp#page/n45/mode/2up


Unfortunately, gum rosin is no longer commercially produced from this species, largely due to over-logging and mismanagement throughout the twentieth century. If you live in the Southeastern US then you could probably find a few Longleaf pine trees to tap but you'd need to learn how to do it sustainably, without killing the trees and gain the landowner's permission. You wouldn't necessary have to distill the turpentine, you could just gently heat the resin and let the turpentine vent to the atmosphere. The saponification is actually more efficient if a small amount of turpentine is left in the rosin.

If you can't find any Pinus palustris trees then the most closely related species are Pinus elliottii var densa (a hybrid between Pinus elliottii var elliottii and Pinus palustris), closely followed by Pinus echinata (Shortleaf pine) and Pinus taeda (Loblolly pine). However, these are also in the Southeastern US, so it wouldn't be practical for many. There's also no guarantee that they would produce a similar smelling rosin to Pinus palustris, although the rosin would probably still smell nice. If you're not in the Southeastern US, or you can't be bothered to tap your own trees then it may be worth testing a sample of Honduran rosin. The reason being that it is primarily produced from Pinus oocarpa and Pinus caribaea var hondurensis, which both share a close, common ancestor with Pinus palustris. That being said, there's no reason why you have to use rosins that smell like that of Pinus palustris. Cedar rosin does sound very nice also.

 

[Dorymae]

http://shop.chemicalstore.com/navigation/detail.asp?MySessionID=178-722829257&id=HROSIN

http://shop.chemicalstore.com/navigation/search.asp

For those in the EU : http://www.goldleafsupplies.co.uk/acatalog/Colophony-Resin---1Kg-7559_a.html

Not sure if this is the right stuff but it looks interesting.

 

[lady-of-4]

Yes that's the right stuff. There are varying colors of rosin from almost black, to as DeeAnna said, water white. With quality being directly related to color, and water white being the best quality.

 

[Pears]

That's the one, Dorymae. That particular company sources their Honduran rosin from PDM Chemicals, who in turn source it from Industria Resinera Bahr S.A, in Honduras. I can't guarantee that it will be anything like the rosin from Pinus palustris but it's well worth testing. Either way, it's still likely to produce a decent soap. Pinus oocarpa constitutes about 66% of the pine forests of Honduras, so it's the primary source of rosin in Honduras. A smaller amount is produced from Pinus caribaea var hondurensis.

It may seem odd that these species would share a close, common ancestor with a Southeastern US species, but ancestral Pinus palustris is believed to have originated from much further west than it is today. Similarly, Pinus oocarpa is believed to have originated further north, in the Southwestern US, or Mexico. This is believed to be the region from which their closest, common ancestor diverged. Ofcourse, a lot can happen in a few million years. Pinus palustris evolved into a species which specializes in fire resistance, which may well have changed it's resin composition. There may still be some noticeable similarities between the two species, however.

The rosin from Pinus sylvestris, in Europe, also produces a deep smelling soap, although it's not as good as that from Pinus palustris. The smell is more similar when it's run under hot water. It tends to produce quite a dark soap, even if the rosin is WW grade. Perhaps it's due to a particular resin acid. I quite like a darker, amber soap though.

 

[lady-of-4]

Pears, it sounds like you know a lot about this. Maybe you can share your personal experiences with it?


I've also found the SAP value to be an average of .182 or 182. And that is the value used in Catherine Failor's latest combo edition of Transparent and Liquid Soap Making.

 

[Pears]

Hi lady, my knowledge largely comes from research on botany, perfumery and historical soap manufacture. I'm in the process of writing a detailed report on Pears soap, which is a rosin based soap. I've also been working as a consultant for a couple of manufacturers, who wish to bring a Pears type soap to market. Unilever reformulated Pears on more than one occasion and many previously loyal customers wish to see a return of the original Pears, or atleast something in the spirit of the original.

With regard to rosin soap, you may wish to try adding a little unrefined palm oil, aka red Palm oil. It was historically used in rosin soaps to correct the aroma of the rosin and to brighten the color. It can cloud liquid soaps if too much is used but up to about 5-7% in the oil blend should be okay, especially when rosin has been included. I don't particularly agree with the use of Palm oil, except when it provides a function that alternatives wouldn't. I'm not opposed to it's use in such situation, providing that it's organically and sustainably produced.

 

[herackonchiasa]

http://m.diamondgforestproducts.com/?url=http://www.diamondgforestproducts.com/products.html#2603