Animal or Vegetable?
Deciding whether to use animal or vegetable oils or a combination of both is each soapmaker's choice. Excellent soap can be made from either. Most soapmakers use both at some point. No matter what fats and oils you choose to use, research their properties, benefits, and uses in soapmaking. Finding an oil blend that suits you to perfection is one of the most gratifying experiences in soapmaking.
Animal Fats
Common animal fats come from cattle and pigs, but some exotic animal fats such as emu oil are gaining great popularity. You can purchase animal fats clean and ready to use, or you can render the fats from meat yourself.
All animal fats, with the exception of butter fat and lanolin, come from slaughtered animals, and are a way of using the entire animal. Hunters often find themselves with fat from deer, elk, and other game that can be rendered into useful soapmaking fat. People who raise small flocks of food animals generally like to put as much of the processed animals to use as possible, and rendering their fat and making it into soap can become another way to accomplish this.
Emu oil is a by-product of processing the large flightless birds for meat. The oil is becoming extremely popular in soapmaking and other cosmetic applications. It is reported to have many therapeutic and healing properties. Emu ranching is becoming popular in the United States because emus provide low-fat, high-protein meat.
Lard is the animal fat most accessible to home soapers. You can buy blocks of clean lard, ready for soapmaking, at the grocery store in the section with butter. Lard makes a very hard bar of soap and is favored by many soapmakers.
Butter, of course, comes from milk. Butter may be used as a soapmaking fat, but it has a high rate of rancidity so is best used in small amounts, if at all. Milk soaps use the butterfat from goat and cow milk to great skin-care advantage.
Lanolin is the fat from the wool of sheep, and it is processed out of the fleece after shearing. You are familiar with the scent of lanolin if you've worn a hand-knitted wool sweater. It is very emollient and is best used as a super-fatting agent.
Vegetable Fats
Contemporary soapmaking techniques have made the use of vegetable fats a viable alternative to animal fats. Combining various vegetable oils in specific combinations can produce hard, long-lasting bars. Vegetable oils are readily available, and many are very inexpensive.
Keep in mind that you should never use mineral oil or petroleum jelly in handmade soap, as they do not react with caustics in a way that creates soap. They can be used in small amounts as a superfatting agent, but in general they do not perform well with the water necessary to make soap foam.
There are many reasons some soapers prefer all-vegetable soaps. Vegetable fats tend to be less pore-clogging than animal fat. Some people find the smell of animal fats off-putting, although in a carefully formulated recipe there will be no unpleasant odor. Still others choose to use vegetable fats exclusively because they don't care for the idea of killing animals for human consumption or cosmetic use.
