Cold Process Soap for One 12 oz Can of Lye-recipe by James Hershberger and the original Walton Feed web site.

Ingredients:

  • 1 can (12 oz or 340 grams) 100% lye
  • 21 1/2 oz (605 gms) ice cold or part frozen distilled water
  • 5 lbs, 7 1/3 oz (2.48 kg) lard or all vegetable shortening

Equipment:

  • 1 ea, 1-2 quart Pyrex or oven ware bowl
  • 1 ea, 4-6 quart plastic bowl or stainless or cast iron pot
  • 1 ea, plastic, wooden or stainless big spoon
  • 1 ea, shallow cardboard box lined with plastic trash bag
  • Rubber gloves
  • Canning pot (for water bath if you use plastic reaction bowl)

Instructions: Prepare the lye water by freezing 1/2 of the water into ice cubes.  Put the ice cubes and the rest of the water into the 1 to 2 quart bowl.  Using the stirring spoon (known to soap makers as the "crutch"), pour lye slowly into the ice and water, stirring until the lye is all dissolved. Take great care with the lye, it is very caustic and will burn the skin and eyes!  Any splatters must be washed off immediately with lots of water!

Cover the solution to keep out air and allow to cool (or warm up ) to about 85 degrees F. Melt the fat in the 4-6 quart bowl or pot. Don't use aluminum or galvanized bowls! Plastic ware can be heated in the water bath. When the fat is melted, cool it down to 95 degrees F. Prepare the box with it’s plastic trash bag lining, so the fresh liquid soap can't leak out. When all is ready, begin to stir the liquid fat in a clockwise direction while pouring the lye water into it in a thin stream (pencil size or thinner) until it is all added. Crutch (stir) the mix vigorously, using “S” pattern or use a hand blender alternating with a circular pattern until the mix begins to cool and thicken. At this point do NOT stop or the mix may separate! First the soap will be murky, then creamy, then like heavy cream and finally, like hot cooked pudding and will show traces when you dribble a stream from the crutch onto the surface. This process can take from 10 minutes to 45 minutes, depending on the temperature, weather and purity of your ingredients. Stir vigorously but patiently! With hand blender stir time is cut to 1/10 of the regular time. When your "trace" does not sink back into the surface, the soap is ready to pour into the lined box.  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. After 3-5 hours the soap may be cut into bars with a table knife, NOT a sharp knife. Allow the soap to cure in the box for about a week before breaking it up and handling it, and another month before using it. The old farm ladies carefully "tasted" the fresh soap with the tip of their tongues for the sharp bite of unreacted lye. 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. Should 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. 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.  You might 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. 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 degree) 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.