How to make a simple lye and lard soap, and check your scale.

How to make a simple lard and lye soap. This recipe is calculated for the convenience of using 1 pound blocks of lard from the grocery store, and how to check the accuracy of your scale.

You do not need exotic ingredients to make soap - just lard, lye and water. Keep it simple. These ingredients have been used for centuries to make soap. Lard by itself is disgusting, and lye by itself is dangerous, but together it makes a soap good for everyday use. It does not lather up as much as commercial soaps, but lasts much longer.

Lard is pig fat, but other animal fats and vegetable oils will work too, but the formula would need to change. Basic hand or bath soap making video instructions can be found on YouTube at: Becky's Homemade Bar Soap Recipe: How to Make Soap with Lye (link below). Her video is where I got the confidence to make lye soap.  Most websites and videos do a poor job of explaining what to do, what to use and how to do it; hers is by far the best I've seen. Considering the hazardous nature of lye, you had better know what you are doing. Some online recipes are dangerously vague or poorly written. Others make it more complex than it really is, or use exotic ingredients.

https://www.youtube.com/watch?v=xlUM_-7Nr_Y

Follow all safety precautions she indicates! Lye and the lye water mixture can be very dangerous in concentrated form, until added to the lard and the chemical reaction to make soap takes place. If you are looking at other recipes, calculate the ratio of lye to lard. Becky's recipe calls out for 40 oz lard, 5.4 oz lye and 13.5 oz water. This ratio is what I use, but her recipe makes more soap than an average family might use in a year. I found some variability of recipes in the water amount used, but the ratio of lye to lard will determine if your soap might be too harsh or too mushy. Some recipes recommend a smaller amount of water.

Some special items you may want to purchase:

A digital scale, accurate from 1 ounce to several pounds. Very important. Test the accuracy and repeatability first. A one pound block of lard and paper packaging should weigh just slightly over one pound, or weigh an unopened bag of sugar or flour. It is a safe assumption to say a one pound block of lard from the store will weigh one pound, within a percent or two. Check the accuracy at the low end of the scale, which is critical for measuring the amount of lye. Five U.S. quarter dollar coins should weigh exactly 1.00 ounces. If you want to be low tech or cheap, make a balance scale, and use quarters to balance out the lye. Weigh the lye a couple times if you are not certain of the accuracy of your scale, especially with a spring type scale.  2.2 oz. of lye would be the same weight as 11 quarters. Measuring lye by volume, rather than weight, is not as accurate.

Rubber gloves and goggles, and maybe even a face mask if you have one. Even if it is not needed, it helps make you safety conscious.

Soap mold. You might find something adequate around the house, like milk cartons.

Stick (hand or immersion) blender. Hand mixing takes much, much longer. A regular kitchen mixer gets too messy.

Digital thermometer. (recommended) from 70 F to 200 F range.

This recipe is calculated for the convenience of using the basic ingredient for soap - a 1 pound block of lard. I bought lard from Cub Foods, $1.89 for a 1 pound block (Nov 2020). I used “Rooto Household Drain Opener” (crystals) for about $5, for 16 ounces (2015). I found mine at a local Ace hardware store. Important: the label on the package must say 100% lye, not just "drain cleaner".  100% lye may be hard to find. Look online, if you can't find it locally. I have never tried making lye from wood ashes, but it looks like a real iffy thing to try, to get the right concentration. Never mix lye with other chemicals – dangerous gasses may be produced.

One pound of lard is about the same size as a pound of butter.

Make sure the label says 100% lye, if you are using drain cleaner.

My recipe for single batch lard and lye soap.

Ingredients:

1 pound of lard = 25 cubic inches - The same size as1 pound of butter.

2.2 ounces of lye crystals = negligible volume increase.

5.4 ounces of water = 10 cubic inches. I used city tap water. I doubt if people used distilled water 200 years ago. Some recipes call out for less water.

I have calculated the approximate volume of the lard and water, so you can adjust the recipe to make the amount of soap to fit your soap mold and to use full packages of lard. You might want to double the recipe depending on the size soap mold you have, or the amount of lard you have. The recipe above would make about 35 cubic inches of soap. As far as volume in cups, I calculated it would be about 2 1/2 cups. For a single batch, I used two ea. 2 qt. milk carton bottoms, and cut the blocks in half after it cured. 

2 quart milk carton 1” high = 14.4 cu in, 1 quart milk carton 1” high = 7.8 cu in. Cut off all but the bottom third of the milk carton, and mark the inside of the carton with a Sharpie at .5 inch intervals, to fill them to equal heights. A single batch fills two - 2 quart cartons about 1.2" deep.

Below: Half a batch of aged soap (two pictures of the same bars). It cost me less than $0.75 per bar to make this, and each bar is over 4 ounces. A single batch poured into in two 2 qt. milk cartons, and each soap block cut in half as pictured, makes a large size bar of soap. Most lye soaps purchased in small quantities cost over $1 per ounce.

New soap, one day old. A full batch with 1 pound lard.

Safety precautions:

Do not make this while young children or active pets are around.

Use rubber gloves and goggles when handling lye or the lye water mixture.

Add the lye granules slowly into the water.

Add the lye water mixture slowly to the melted lard.

Have a vinegar and water solution handy to neutralize the lye if splashed or spilled, or to rinse anything that has held lye.

Have lots of hot water and towels for clean up.

Seal the lye container with tape when done, and store out of the reach of children.

My soap making instructions - after you've seen Becky's video.

1.      Mix the lye into the water first, to give the lye water time to cool down. Some say to 80 degrees F, others say 100 degrees or higher. It shouldn't be hotter than the lard, I think. Mix it in a ceramic, glass or stainless steel bowl. Stainless steel would be best, so you can feel the temperature on the outside of the bowl.

2.      Melt the lard in a stainless steel pan on low heat, until the lard is all melted, and let it cool down to 130 degrees F.  Many websites say to cool down lard to 80 to 100 degrees F, but the lard is solid again at that temperature. Do they actually measure the temperature, or is each person copying another person's wrong instructions?  Have they actually made lye soap with lard? At room temperature, the store lard is still a solid block; as hard as butter at the same temperature.

 2021 - Lately, I have been melting the lard in a plastic pail, in a microwave, a minute at a time. I combine the lye water and mix it in the same container, and throw away the container when done. It saves a lot of hot water and cleanup time.

3.     Mix the cooled lye/water mixture into the lard when lard is near 130 degrees F, or (if you don't have a thermometer) when the lard is just starting to become slightly opaque as it cools down. The store lard I used was clear as water above 130 degrees.

4.   Mix with a stick blender until the soap mixture begins to trace (or thicken), and pour into mold. See Becky's video.

Clean up is hard to do, unless you can do it outdoors, with lots of hot water.

Let the soap sit in the mold for a minimum of one day. The larger the mold, the longer it takes to cure. If it's still mushy inside, you removed the soap too soon. The soap might still be soft in the middle, even after two days. Age for three weeks before using.  The soap starts out white in color, but will yellow over time.

To clean the stick blender, I wipe off as much soap as I can, then incrementally heat water in a plastic container in the microwave up to about 175 degrees F, then run the stick blender in that water. Throw that water outside when you are done, not down the drain.

A cartoon from 1884, when cartoonists were artists with a sense of humor: