Making lye soaps is not that hard or exact a science and at one time it was the only source of laundry soap as well as bath soap and body soap. Understanding the organic soap making process and the dangers involved with making lye soap, are important. Making homemade lye soaps using lard, allows for the recycling of what would otherwise be waste products from cooking. Besides the soap ingredients, the following soap supplies will be needed for making lye soaps. Once kitchen utensils have been used for soap making do not use them for food purposes again.
heat source -stove top or outside cooker
large earthenware pot or enamel coated pot - do not use metal unless it is cast iron
large wooden spoon
Soap molds- non metal
Thermometer for cooking
Gloves and protective clothing
First, before making lye soaps to be used as bath soap or laundry soap, read about and understand the dangers involved with working with lye. There are many cautions and facts that should be known. Second, hot fat is also dangerous and can cause very painful, even life threatening burns if not handled safely. Be sure you are able to turn your total attention to the soap making process once you begin it. Do not have young children or pets around when soap making with lye. Organic soap is a mixture of fats, lye, and water, that undergoes a chemical reaction called saponification when mixed together in the right proportions. There are two main methods for making lye soaps, cold and boiling. This article covers the cold process because it is easier.
Decide what kind of homemade lye soaps are wanted and what other ingredients to add to the bars of soap. There are many ingredients that can be added to homemade soap to give it the properties wanted. Bleach can be added to laundry soap to help it whiten clothes and borax will help it make suds. Perfumes for smell, and colorings can be added to bath and body soap if wanted. Don't add perfumes with alcohol or food colorings that may stain. There are many excellent books and soap recipes on the web for making organic soaps of all kinds. Homemade soap has to dissolve to do the best job of cleaning and it will not dissolve in cold water. Hot water must be used or the soap will leave a gummy deposit in the sink or laundry tub and on whatever is being cleaned. Organic soaps also will not suds well in hard water, but adding borax will help this. Lavender oil, essence of roses oil, and lemon oil make wonderful additions for making scented soap. You can add ground pumice to bar soap to make a good hand scrubbing soap. If your home water is hard be sure to use distilled water in the soap making process.
Collect the types of fat needed for the homemade lye soaps. The type of lard or animal fat used will affect the soap quality. Chicken fat makes a very soft soap, sheep fat - a hard soap, pig fat - good but slightly soft soap, and beef fat makes a hard dry soap. By mixing these different types of fats and by also using vegetable fats -such as coconut oil or olive oil, it is possible to get the type of lye soaps wanted. Collect the fat by saving trimmings and drippings from cooking and placing them in a covered container in the fridge or freezer. When there is enough -about 5 cups, it needs to be cleaned by boiling it to remove any trash and salts. Place it in a large open pot and slowly bring it to a boil then slowly add 4 cups of cold water while stirring it to break up lumps. Bring it back to a boil then let cool and settle without stirring. When cool, skim off the fat or let it harden and then turn it over and cut away the trashy part. The cleaner and whiter the fat the better the lye soaps will be. It may be necessary to clean the fat more than once and to strain it. Store bought shortening or canned lard can be used to make lye soaps if you do not want to go through the process of collecting and cleaning your own fats.
Make or buy molds for homemade soap. For lye soap these need to be non metal. Prepare the molds before mixing up the soap. Grease them with some cooking oil or Vaseline and if they are small set them on a tray to make them easy to fill and move. Plan for where the soap molds will be set while the soap hardens. It needs to be a cool place and it may take a week or more before the organic soaps harden if soft fats were used.
To make lye soaps, mix the lye with the fat and water in the following ratios: 1/2 cup lye to 4 cups of melted fat and 1 1/2 cups of water. First add the lye to the water slowly, and stir with a wooden spoon to dissolve the lye completely. Do this outside on a surface that can take heat because the solution will get hot as the lye reacts with the water. Wear gloves and protective clothing and do not breathe the fumes. While this is cooling get the soap molds ready and melt the fat heating it to a temperature of around 125 degrees. The lye solution should be around 75 to 80 degrees when the melted fat is added to it in a stoneware container. When combining the mixture, stir it constantly in one direction and add any other (borax, perfume, etc.) ingredients now. While stirring watch for the mixture to start thickening. This means it is turning to soap and may take anywhere from 20 minutes to an hour depending on the temperature and humidity. If the soap starts to settle out stir it harder even beating it till it thickens to a pudding like consistency. When the wooden spoon will stand up in the center it is ready to pour into the soap molds.
Fill the prepared molds and smooth off the tops. Set the soap filled molds aside to harden. When the homemade lye soap is hard enough to remove from the molds but still soft enough to cut, remove from the molds and cut to size if necessary. A large sharp knife or thin wire can be used to cut the soap. The bars of soap must age to mellow the lye and make it safe for using on the skin as bath and body soap. To age the lye soaps and to allow it to harden completely leave it out where air can circulate around it for some two months. Don't let it freeze for at least 3 weeks so the lye will have time to fully react with the fat. Homemade soap must be adequately aged before it is safe for delicate skin. Check it on yourself before using it on children. After aging wrap the bars of soap in tissue paper or plastic wrap before storing the homemade lye soap. The soap may be dark right after you make it but if the fat was clean it should turn white as it ages. Rinse water from washing with homemade soap is safe to use on plants and for livestock.