Making Pine Tar soap
Pine tar (PT) soap is an interesting soap to make and use. Soaps containing tar -- pine tar, birch tar, peat tar, and coal tar -- have been used for centuries to control and soothe skin problems such as dermatitis, dandruff, and eczema. The tar that is easiest for handcrafted soap makers to find nowadays is pine tar.
Pine tar has a notorious reputation among soapers for a number of reasons. Probably the biggest reason is pine tar causes the soap batter to thicken very quickly -- sometimes in seconds. The deeply smoky smell of pine tar can be overwhelming to some people, especially when the soap is freshly made. The color of a bar of pine tar soap is typically dark brown to almost black, and the lather it makes is also brown. The soap tends to be softer and shorter lived in the bath than a comparable soap without pine tar.
What is pine tar?
Pine tar is often made from the waste roots and stumps of pine trees cut down for lumber. The wood is slowly heated in the absence of oxygen in a process called pyrolysis. The heat turns some chemicals in the wood into a dark, sticky liquid tar that oozes out of the wood. The solids that remain are converted into charcoal. The absence of oxygen during this process prevents the charcoal and tar from burning.
The smoky-smelling pine tar was made in huge quantities in the era of wooden sailing ships. It was used in the packing material (oakum) that sealed the cracks between planks in ships' hulls. Nowadays, the market for pine tar is small but steady. It is used on baseball bats to improve grip and on horses' hooves as a protective dressing. It is sometimes used as a protective coating on wood buildings, fences, and other outdoor structures. The charcoal is used for cooking, blacksmithing, or any other purpose that needs a hot, nearly smokeless fire.
Is pine tar the same as rosin?
Pine tar is not the same as rosin (also called colophony). Rosin is a clear golden solid material made from pine sap, not pine wood.
The sap is collected by tapping pine trees, similar to how maple trees are tapped to make maple syrup. The pine sap is boiled and the vapors that rise from the boiling sap are collected and condensed into liquid turpentine. Rosin is the solid material that remains after the turpentine is removed.
Rosin can be used to make soap too, but rosin soap is different than pine tar soap. It does not appear from my reading that rosin soaps were historically used for treating skin problems.
A digression about rosin --
Rosin was used by soap makers of the 1700s and 1800s as a cheap filler to reduce the amount of expensive fats in the soap and to add detergency (cleaning power) to household and laundry soaps. It is no longer cheap, and I am not really sure it does any more to make a highly cleansing soap than using plenty of coconut oil.
Its biggest benefit nowadays might be for making transparent soaps. Rosin is a difficult additive to work with, even more so than pine tar. First off, rosin must be heated quite hot and it must be melted into a smooth syrup before use. If there is any stringy texture, the rosin is not yet fully melted even if it appears to be a clear liquid.
When added to soap batter, rosin and lye react very fast and create a lot of heat. Without care, the soap batter may expand in the soap pot or mold and even "volcano" over the sides.
Does pine tar work?
The question of whether pine tar really works to treat skin issues has been debated for many years. Even in the 1800s and early 1900s, authors of soap making manuals were skeptical that pine tar had real medicinal value. They were furthermore unsure about how much pine tar was needed in a soap to be effective, assuming there was a real benefit to be had.
Only a limited amount of research has been done in recent decades on the efficacy of pine tar to treat skin conditions. The studies I did discover showed pine tar had little or no medicinal value. Based on this, the US FDA has determined pine tar is not an effective drug. That means pine tar soap cannot be legally sold to consumers in the United States as a medicinal product. If a seller makes an outright claim or even implies that pine tar soap is a drug (a medicine), the FDA can take disciplinary action.
On the other hand, there are decades of of anecdotal stories that say pine tar does help some skin issues. The commercial brand "Grandpa's" pine tar soap gets enthusiastic reviews from users who claim this soap controls or cures a variety of skin ailments. These claims seem pretty amazing, especially since I suspect "Grandpa's" has only a small amount of pine tar in the recipe -- perhaps 5% or less.
Do the skeptical reviews versus glowing testimonials mean the placebo effect is alive and well? Or does pine tar really work? I really don't know!
Can I make health claims for my soap with pine tar?
In the USA, you cannot make health claims for pine tar soap. You can call it "Pine Tar Soap" certainly, and you can list pine tar in the ingredients list. But that is it. There are two reasons for this.
First and most important -- the FDA (US Food and Drug Administration) does not recognize pine tar as a useful drug. If it is not on their drug list, you can get into trouble by claiming it does have health benefits.
Secondly, if the FDA did classify pine tar as a useful drug, any claims of health benefits will change your product from a simple soap with minimal labeling and no testing requirements into a drug with stringent labeling and testing requirements.
Many soapers try to get around this issue by implying health benefits without actually making direct claims. The FDA takes a dim view of such "weasel words" no matter how or where they are presented. You cannot get around the FDA rules with the ruse of presenting customer testimonials about how well pine tar works or by explaining how pine tar was used in history to treat medical problems. You just can't.
It's soap. It cleans. It has pine tar in it. Leave it at that.
How much to use?
Let's assume for the sake of argument that pine tar soap is helpful for some skin conditions. How much pine tar do people use in soap?
Most of the recipes dating from a century ago to modern times call for pine tar ranging from 5% to 25% of the total oil weight. If the positive user reviews for Grandpa's soap are taken at face value, then a soap with a small amount of pine tar -- say in the 5% range -- apparently does work.
On the other extreme, some soapers claim 20% is the minimum needed for efficacy. I have never seen any explanation or reasoning to support this claim, so I am skeptical. A few soapers have tried as high as 30%, but report the soap has problems with long-lasting softness.
I would say most soapers use pine tar at 10% to 15% of the total oil weight.
I want to add that how one uses the soap might be more important than the amount of pine tar in the soap. If you lather up and rinse off, as most people use soap in the bath, the pine tar soap will have very little time to have an effect, whether good or bad. If you lather up and let the suds stay on the skin for some time, then the soap will have a far better chance of doing some good.
Finding pine tar
Unless you live in a baseball-crazy town or near a traditional wooden boat builder, pine tar is most likely to be found in the equine section of "feed and seed" stores or in tack and saddlery shops.
Bickmore, Farnam, and Su-Per Pine Tar are three veterinary brands sold in the US.
Auson from Sweden produces several grades of pine tar. I'm particularly fond of their Dalbrand Tratjara (Dale Burned Wood Tar) #773. A good alternate is Akta Tratjara (Genuine Wood Tar) #850.
Whatever brand you use, make sure the label says the product is 100% pine tar. Some products are a mixture of pine tar mixed with other ingredients. You want to use only 100% pine tar in your soap.
Pine tar safety
Some people are concerned that pine tar may contain creosote, which is considered carcinogenic. Given that pine tar is made by pyrolysis (incomplete combustion), it is very likely that some compounds in pine tar are indeed carcinogenic.
This is also true of barbecued meats, crispy bacon, blazing campfires, deep-fried foods, and many other things that give pleasure to everyday life. I accept the risk, enjoy these things in moderation, and don't worry about it.
Handling pine tar
Pine tar is a thick sticky syrup that ranges from dark brown to almost black. Before use, stir the product until any solids on the bottom of the can are mixed into the whole.
I have never felt the need to warm pine tar before pouring it, but some people warm the container in a bath of hot water (bain marie) so the pine tar is easier to pour. If you do warm the pine tar, use a warm-water bath only. Do NOT put the can directly on a stove burner or in the microwave -- pine tar can catch fire and burn!
Some people throw away anything that touches pine tar. This is absolutely not necessary. Equipment and utensils will be clean and odor free after a good wash. If you get it on your hands or fabrics, wash well in warm soapy water.
Designing a pine tar soap recipe
When designing a pine-tar soap recipe, I suggest using more stearic and palmitic acids than you might normally use. They will add hardness and reduce the solubility, both of which will offset the softness that pine tar adds to soap. These fatty acids are found in tallow, lard, palm oil, and butters such as shea butter and cocoa butter.
Use only a moderate amount of soft (liquid) fats such as olive, soy, canola, avocado, safflower, sunflower, etc. These oils tend to make soap softer and/or more soluble in water.
Fats high in lauric or myristic acid make soap that is physically hard and lathers well. On the downside, a soap high in these fatty acids will dissolve quickly in water and may be overly drying to the skin. I recommend using them in small to moderate amounts in a pine tar recipe. These fatty acids are found in coconut oil, palm kernel oil, and babassu oil.
Use a low to moderate superfat to minimize the softness of the soap. I recommend up to 5%.
If you are normally a "full water" soaper, consider using a slightly higher lye solution concentration such as 30% or 33%. Slightly less water in the recipe will help the soap firm up faster. Some will say to use "full water" to slow how fast the batter comes to trace, but frankly, pine tar batter is going to trace really fast. I recommend using a little less water to get a firm soap that can be unmolded and cut quicker and easier.
Soap recipe examples
There are about as many recipes for PT soap as there are soap makers, so I am not the only one with a good recipe for this type of soap. But to give you some ideas, here are a couple of suggestions.
This is one blend of PT and fat that I have used. This soap was borderline brittle due to the tallow. Next time, I might reduce the tallow to 10% to 15% and add the extra to the lard for a firm but not brittle bar.
Castor Bean Oil 5%
Pine tar 10%
Coconut Oil 10%
Here is another blend that is a nicely-firm, classic lard soap. It was ready to be cut 12-18 hours after pouring. Olive oil can be substituted for some or all of the avocado and sunflower oils.
Avocado Oil 5%
Pine tar 10%
Coconut Oil 12%
Sunflower, high oleic 18%
For each blend, I used these parameters to create a complete recipe--
Lye solution concentration of 31% to 33%.
Distilled water as the only water-phase liquid.
No fragrance. No other additives.
If you do not want to use animal fats in your soap, then substitute palm oil, cocoa butter, and/or other high stearic, high palmitic butters.
Another pine tar soap recipe and a step-by-step tutorial from an experienced soap maker can be found here: David Fischer's pine tar soap....
How to make pine tar soap
Prepare a slab or loaf mold. I don't recommend using individual bar molds for this soap due to how fast this soap usually sets up. Pine tar will not give you enough time to fill individual molds.
Make sure all fats are fully melted, but are no more than pleasantly warm to the touch (under 120 F or 50 C).
Split the fats roughly in half. Measure the pine tar into one half. If you are adding fragrance, pour your fragrance into this portion as well. Blend until the mixture has a uniform appearance using a stick blender (SB) and spatula or whisk.
Allow the lye to cool until just warm to the touch. Add the lye to the plain half of the fats. Bring this soap batter to a definite, light trace as you normally would.
At this point, if using a stick blender, set the SB aside and grab a sturdy lye-safe spatula. Also check your mold to make sure it is ready for instant use and take a deep calming breath. The rodeo is about to begin!
Pour the PT-fat mixture into the soap batter. Gently hand stir until the surface of the batter begins to lose its shiny oily-smooth look and begins to look dull and slightly grainy or curdled. This may happen in well under 1 minute (that's my usual experience) or it may take minutes. Once the batter looks dull and grainy, do NOT stir longer -- not even one more go around!
If you are lucky, pour the fluid batter immediately into a mold. If you are not so lucky, scrape the thickened batter into the mold as best you can.
Let the soap saponify at room temperature. Leave it uncovered or only lightly covered with a towel. Do not CPOP.
About the super-fast thickening of pine tar soap
Once PT soap starts to saponify, it usually thickens so quickly it doesn't show the usual signs of "trace" as you see with other soap batters. At one moment, the surface of batter will be shiny and smooth, a second or two later the surface will look grainy and dull, and a few moments after that the batter will become unpourable brownie batter.
One extra go-around with the spatula can make the difference between a fluid, pourable batter and a thick, sticky paste that has to be scraped and spooned into the mold. The goal is to pour right at the beginning of that "grainy and dull" stage, but don't be hard on yourself if it takes a few tries to catch that magic moment.
I found out the hard way to never mix pure pine tar into soap batter at trace. It is almost impossible to get the PT thoroughly mixed in before the batter becomes unpourable. I have learned instead to mix the pine tar and fats together before I allow the pine tar and lye to see each other. I have tried two methods and both work pretty well --
Method 1 is to mix the PT with all of the oils first and then add the lye. I use one or maybe two short, careful bursts of the stick blender to emulsify the lye with the fats. After that, I hand stir with a spatula until the batter looks dull and slightly grainy on the surface, and then quickly pour the batter into the mold.
Method 2 (the method used in the previous section "How to make pine tar soap") is to split the fats into two roughly equal portions. I add the PT to one half, blend really well, and set that half aside. I add the lye solution to the other half and bring that batter to light trace. I then hand stir the PT mixture into the soap batter, continue to slowly hand stir until the batter looks dull and slightly grainy, and then quickly pour the batter into the mold.
The second method avoids having to stick blend the batter after the lye sees the PT. This is the method I now prefer to use.
About the strong smell of pine tar
Yes, pine tar soap smells. The smoky odor will never go away, but it definitely softens and lightens with time -- at least that has been true for all the batches I've made (nine as of this writing).
It seemed as if the odor from my first batch would never go away! But now that I have made a few batches of PT soap, it seems that the odor is becoming less objectionable and more familiar and comforting. When I made my last batch, I put a box of freshly cut bars on top of a kitchen cupboard. I was in the kitchen all day, but I could not smell the pine tar unless I stuck my nose directly in the box.
The brand may also make a difference in the scent. I started with the Bickmore brand that is available in the US, and that product has a bit of a burnt rubber tang. I gather the Farnam and Su-Per Pine Tar products smell comparable to Bickmore from what others have said. The Swedish Auson "Kiln Burn" pine tar I am using now has a pungent smoky campfire odor. It is strong, yes, but it does not have much of a burnt rubber overtone.
I hope this article has given you some good tips for making your own batch of pine tar soap. Happy soaping!