Hot Process soap-making Guide

Hot process soap is much easier to make than it sounds. It does take some time cooking it, but your soap will be finished in a couple of days instead of weeks or month.

You will need a double boiler or a slow cooker like a crockpot to make hot process soap, but never mind buying a lot of fancy equipment.

How to “make” your own double boiler

You can make your own double boiler from just a bowl, a pot, some water, and a lid. The bowl can be made out of heat resistant glass or metal – just not aluminum. A plastic bowl will also do if it is heat resistant.

Find a bowl that is a little bigger than the pot so rests on the edge of the pot. That will stop the water from evaporating too much and stop the bowl from falling into the water. Also, make sure the bowl doesn’t sit on the bottom of the pot.
Find a lid that fits on top of the bowl – It can be a pan or anything else heavy enough to close the bowl.

Homemade double boiler

Fill the pot approx 2/3 with water, just enough to keep the bowl in place.

Step by step guide to hot process soap

If you haven’t already then start by reading the safety guide to soap making.

  • Measure all your ingredients
  • Make your lye from adding NaOH to water (not the other way around)
  • Melt your hard oils and butters in the slow cooker, and add the rest of the oils
  • Place you bowl or slow cooker securely on a table in a ventilated place
  • Carefully ad the lye to the oils and mix them. Use a stick blender until trace
  • Put the bowl back into the pot (if you use a homemade double boiler) and heat up the batter to no more than 200 degrees F (93 C)
  • After 10 – 20 minutes, the soap batter will look like it separates oil from water
Be sure to stir the soap to get it heated evenly
  • Stir the batter and heat for 15-20 minutes more, until it starts to rise. Be careful and keep stirring, to keep it from rising too much and spill
  • Heat for another 15 – 20 minutes until the batter looks something like petroleum jelly (vaseline)
Soap looks like petroleum jelly when finished

Some people add colors simultaneously with mixing the oils before cooking, and some like to add them after cooking. Maybe it depends on the type of colorant, but I like to do it after the hot process.

Essential oils and other scents should be added when the finished soap has cooled down a bit. Many of the essential oils will evaporate if heated, but you have to check the ideal temperature on each oil.

  • Mold you soap after adding color or scent, and leave it for about 24 hours until hard enough to unmold and cut
  • The soap is ready to use (check pH value first, it should be 10 or less) but it will last longer if left to dry a week or so
Turmeric soap
Hot process soap the day after cooking Recipe