Herbal salves are made by infusing an oil with dried herbs. Good choices for such oils are plant oils that do not easily get rancid. I use one of the following three. You can also combine them.
Olive oil
Sweet almond oil
Jojoba oil
If you try to infuse oil with fresh helbs then you will generally get mold. There are a
few exceptions but in most cases it is very important that oil is only infused with dried
herbs. Such a herbal infusion will normally take 4 to 8 weeks.
To make the infused oil into a nice creamy salve you have to add something that mixes with
oil but is solid at room temperature. Commonly used natural substances are:
Bee's wax: Gently warm up bee's wax and oil. Mix them once they are warm. You need about 1/8 of the oil
weight in bee's wax. Since bee's was and oil weigh about the same by volume you can also
measure the bee's wax out by volume.
Beef tallow: Same process as with bee's wax but you need about 1/2 of the oil weight in
beef tallow.
Beef tallow dilutes the oil a bit more since you need a higher ratio of beef tallow to oil
but it makes a save that is very compatible with human skin. Beef tallow is more similar to
the fats of our own body than bee's wax.
To test if you added the right amount of tallow or bee's wax you can take a drop of the mixture and
put it on a plate that has room temperature. Wait a moment for the drop to come down to room temperature and then check what the consistency it like. If it is too soft then add a tiny amount of bee's wax otherwise add more oil.
A calendula salve made with beef tallow and olive oil
If you want to increase the shelf life of the salve then you could add BHT (butylated hydroxytoluene) to it. Add about 0.1% of BHT (by weight, a tiny amount). BHT is however a totally lab-made chemical. It does not occur naturally and it's a potent fat soluble antioxidant. BHT is approved for use in food (often shown on the label as E321). BHT is sometimes used in combination with BHA. BHT itself has some medical action against viruses. BHA is probably causing cancer while BHT is accused of doing that too but I think that's false. Antioxidants can not cause cancer. BHT might however be an endocrine disrupter (see https://pubmed.ncbi.nlm.nih.gov/11061995/: Estrogenic alkylphenols induce cell death by inhibiting testis endoplasmic reticulum Ca(2+) pumps, published Nov 2, 2000 ). I use only BHT and not BHA if I use something to stabilize the save. I am not worried about the risk of it being an endocrine disrupter. BHT is not accumulating in the body. The liver removes BHT quickly. In most cases it is preferred to store any extra salve jars in the fridge until you start to use them. Make new salves once they are 3 years old. This way you will always have fresh products and you don't need BHT. Almost all commercial salves and cosmetics contain BHT. Sometimes they put the BHT into the plastic package. This way it has still some effect but they don't have to declare it. If you want extend the shelf life a bit but not put BHT into the actual salve then make a separate salve with a high concentration of BHT in it (10%) and rub a tiny amount of that 10% BHT salve onto the inside of your lid. This will prevent your salve from getting rancid early because there is some tiny amount of BHT in the air space above the salve and it's in this area where it would start to get rancid first.
