How to make your own soap

soap in dishHomemade Soap 

This is a nice body and face soap and it is also luxurious and  gentle. It’s a lot of work to make, but it is also a lot of fun. It is a good use for huge quantities of fat left over from cooking.   One of the main ingredients in soap is lye (sodium hydroxide, or NaOH). Lye is extremely caustic even at room temperature, and in this recipe it is heated.  Because of this, you need to exercise extreme care when you make soap. You should always wear shoes (not sandals), long pants, a long-sleeved top, and gloves (rubber dishwashing gloves work best). Also, be sure to wear eye protection. If you get lye on your skin, you can quickly run to the sink and wash it off with LOTS of  cold water; if you get lye in your eyes, rinsing it off  may involve going to the emergency room. You should make certain that children and pets are somewhere else and will not interrupt you. There is no room for mistakes when dealing with lye. 


You will need:

9 lbs. suet (this is also called tallow or beef fat)

1 container lye

3 c. water

2 c. lemon juice

1/4 oz.  volatile fragrance oil (optional)

You will need a large pot (metal or ceramic), deep enough to hold at least 2 gallons, with a  lid. This is for rendering the fat. One long wooden spoon (at least 10″) is required as well. This should be a spoon that you can sacrifice, because the lye will eat away the wood. You will need a large ceramic or glass bowl. This must be capable of holding all the water, lemon juice, and fat with some room to spare. We use a ceramic tub that is about 6 inches high and 24 inches in diameter.  Do not use metal, as it will corrode. Even stainless steel will be damaged. Finally, you will need some glass, ceramic, and/or wooden molds to pour the soap into. We use glass baking dishes; two 8 1/2″ × 14″  glass pans will make bars of soap that are about 1″ to 1 1/2″ thick Again,  DO NOT USE METAL CONTAINERS, as they will corrode.

Make the soap:

Render the fat. To do this, cut the fat into hand-sized pieces and place in a large pot and cover it. Heat on a medium heat until all the fat is melted.

You should stir it occasionally. You should probably plan to turn the fan on high or open your kitchen windows while you are doing this. Cool the fat so that it is below the boiling point of water. Add an equal volume of water to the fat, and bring the mixture to a boil. Cover and let cool over night. Take the fat out of the pot. The easiest way to do this is to slice the fat in half with a knife and then cut wedges. You can push the first wedge down into the water and then lift its neighboring wedge out. Scrape all the non-fat gunk off the bottom of the fat (the side of the fat that was at the fat-water interface).

Measure out six pounds of rendered fat (be accurate with this measurement). Cut the fat into small pieces (about the size of a tennis ball, but square-ish, not round) and place in a bowl. Set up your soap-making work area.  It should be outside, in a very well ventilated area. Also, clear your stove top and open the window in the kitchen before you start making the soap.

On a table, put your ceramic tub, the bowl of fat, the opened container of lye, a container with the water, and a container with the lemon juice. If you will be adding scent, keep its container nearby. Also place your soap mold containers nearby. Put on all your safety gear.


Pour the water into the ceramic tub. Very carefully pour the lye into the tub. This is an exothermic reaction: it gives off heat, which is used to melt the fat. It also gives off odors which you don’t want to breathe in, so keep your head back. Stir the lye to dissolve it in the water.  Then start adding the fat to the water/lye mixture, stirring with the long wooden spoon. Add the fat a bit at a time and stir until it’s all melted.  Then stir in the lemon juice, scent (if you are using it), and pour into molds.

When the soap is firmer but not yet hard, cut into bars with a knife.  It should be hard in an hour or so; you can test it with your finger. Wrap in clean cotton rags and store in a cool, airy place for 3-6 months.

When you clean up the pan that you made the soap in, be somewhat careful as there is probably still some non-reacted lye in the pan.  The only time this has proved to be a problem is when trying to scrape the dry soap that lines the pan off with my fingernail and then a few minutes later noticing that the skin under the fingernail is burning.  The easiest solution is just to wear gloves when you’re cleaning the pan.  It probably also helps to wash with extremely hot water so that the remaining soap (and fat if there is any) melts and dissolves in the water.


Makes 6 pounds of soap.