Homemade Lye Soap (Guest Post #2)

Here is another guest post from my friend Loretta from the Pacific Northwest!

This is a great post and another stepping stone toward her own blog someday!

Cold Process for Homemade Soap


  • 1-2 quart Pyrex or glass bowl

  • 4-6 quart stainless steel or cast iron pot

  • plastic, wooden or stainless big spoon (called a ‘crutch’ by soapmakers)

  • shallow pan lined with plastic (an old brownie pan is perfect)

  • Rubber gloves

  • Thermometer

  • Measuring Scale (a precise one)

  • 10% Vinegar solution and sponge to neutralize lye spills


  • 1 container 12 oz (340 grams) 100% Lye

  • 21 1/2 oz (605 grams) ice cold or part frozen Water

  • 5 lbs, 7 1/3 oz (2.48 kg) Lard or all vegetable shortening


  1. Lye Water – NOTE: Take great care with the lye: it is very caustic and will burn the skin and eyes! Use the rubber gloves and be ready to wipe up splatters with the vinegar sponge.

    1. Put 21 ½ oz (605 grams) of water in the 1-2 quart Pyrex/glass bowl. About half of this should be ICE so that the water is very cold.
    2. Pour 12 oz (340 grams) of lye slowly into the ice water, stirring with the spoon until the lye is all dissolved. It will get very warm.
    3. Cover the solution with a towel and allow it to cool down to 85-90°F (29-30°C).soap 1soap 2soap  3
    4. Lard

      1. Put 5lbs, 7 1/3 oz (2.48 kg) of Lard into the stainless steel or cast iron pot. Do not use aluminum or galvanized pots. Melt the fat over a low heat.
      2. After melting, the fat must cool down to 95-100°F (35-36°C). You want it to remain liquid. Begin saponification right at the point that the fat starts to solidify again.
      3. To cool down the temperature, I put ice water in my kitchen sink and set the pot inside.

    soap 4soap 5soap 6

  2. Soap Pan

    1. Cut a plastic lining to fit inside the pan. You will pour your liquid soap into this pan and let it harden.                                                     soap 7
  1. Saponification (Making the soap!)

    1. When lye water and lard have cooled down to the right temperatures, slowly pour all the lye into the liquid lard while stirring slowly in an “S” or circular pattern. You want a very thin (like a pencil) stream when you pour. soap 8

    1. Continue to stir at a steady pace for many minutes. This may take 10 to 40 minutes to finish. Place the pot in the ice water in the sink and keep stirring!! I stir for 5-6 mins out of the ice water and then 1-2 mins in the ice water.

    2. The mixture will first look very thin and milky. It will be yellowish. Do not stop stirring or the mixture will separate. (If this happens, try reheating the mixture and stirring constantly while it cools down again.)           soap 9

    1. Next it will get thicker and creamier and whiter.

    2. Finally the raw soap will seem like thick cooked pudding.

    3. You will know you are done stirring when you lift the spoon (“crutch”) from the pan and let some of the raw soap dribble down into the mixture and the drips leave little traces on the top of the soap. (Think pudding.) If the drips sink right back into the mixture, keep stirring until you can see them.

      soap 10

    4. Bars of Soap

      1. Pour the mixture into the plastic-lined pan.soap 11

    1. Cut the hardened soap after 10-24 hours with a dull blade. (Something that will not cut through the plastic lining.) You might want to do this again on the same lines the next day as well.                                                      soap 12

    1. Allow the soap to cure (stay, rest) in the pan for a week. Break the soap bars up along the lines that you cut.                                      soap 13

      1. Allow the soap to cure 4 more weeks. After that it is ready to use! You can use this soap for bathing or laundry.                       soap  14

  1. More Information (from the research websites)

    1. Wear rubber gloves and treat the raw soap like you treated the lye water. Wash off all splatters immediately. Have 10% vinegar and water and a sponge to neutralize splatters. (Note: I am very careful and have never burned my skin. I do not like rubber gloves, so don’t use them.)
    2. The old farm ladies carefully “tasted” the fresh soap with the tip of their tongues for the sharp bite of unreacted lye.
    3. The soap from this recipe makes a bath and facial soap, and if you want old fashioned “Grandma’s Lye Soap,” use less fat; about 5 lbs 5 oz instead of the original amount called for in the recipe. Allow this soap to mature in open air for six months. Soap made with less fat was used for laundering clothes. This soap still works well to remove stains and get strong smells out of farm clothes.
    4. If you wish to color your soap you may stir in about 20 gms children’s powder tempura paint when the mix reaches the heavy cream stage. I have also heard of soapmakers using crayon shavings to color soap. I have never done this.
    5. Perfumed soap may be made by adding 60 gms (about 2 oz) of essential oil or perfume just before the soap is thick enough to pour.
    6. Another way to perfume soap is to wait for the unscented soap to cure, and then wrap the soap in muslin, anoint a cloth with perfume and wrap it with the soap in aluminum foil. Set it aside for about six weeks until the perfume has penetrated to the core of the bar.
    7. To re-form the bar into a new shape, place some bars into a ziplock bag and warm them up by immersing the closed bag of soap in hot (120°F ) water for 30 minutes. The soap should be soft enough to cut, make into balls or even press into molds. It sets when it has cooled and rested for an hour or so.
    8. You can try forming soap into special shapes by pouring the raw soap mixture into molds. I have never done this because I make soap for personal use only and I don’t care what they look like.


About CastIronDan

I'm a married father of three from Apple Valley, CA that enjoys Cooking, Roasting Coffee and HomeBrewing.
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10 Responses to Homemade Lye Soap (Guest Post #2)

  1. Lorretta seems very organized. I agree, she should do a blog as well Dan. I like the goat milk soap myself, but this was a very nice post. Keep it up girl.

  2. Ray says:

    Dan, I made my first batch of soap, I have a few questions for Loretta, where can I post or how to get in touch with her?

  3. CastIronDan says:

    Hi Ray, I will get in touch with Loretta today and find out…

  4. Ray says:

    Dan, I followed the directions perfectly, my soap was very hard, very fast. Loretta mentioned cutting the soap with a dull knife and then re-cutting. This was not necessary with my batch, it was very hard and one cut did it. My soap is now cured for almost a week, it has a very white appearance and at first smelled like animal fat, now smells like soap! I think it is good but I was concerned about the fast hardening. Any suggestions or advice?

    • lorettafritz says:

      It sounds like you did a good job on your first batch. I’ve had my soap harden up quickly as well. Sometimes I think I have just stirred it longer and don’t realize it. Wait another 2 weeks and then try a bar on a nasty greasy stain….that will really amaze you!

      • Ray says:

        Used my soap for the first time with a nice hot bath. I will never go back to commercial soap. My skin is nice and clean with no chemical fragrance and it’s less expensive. Thanks so much for everything.

  5. Pingback: CastIronDan is 1 Year Old! | Cast Iron Dan

  6. Thanks for this! I so wantto try this!!!

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