Go Back
Print Pin
4.91 from 11 votes

Simple and Moisturizing Hot Process Soap Recipe

A simple hot process soap recipe suitable for beginners. The final soap bars are a natural creamy to tan color (depending on the type of olive oil used) and have a creamy, yet fluffy lather. The recipe is for a 28 oz (800 g) batch with a 5% superfat and makes 8-10 bars. Full video instruction on making this soap included but be aware that the instructions for adding the superfat separately are not in the video. It's a slightly different method but either way works. See recipe notes for an explanation.
Course Soap recipe
Cuisine Herbal soap
Keyword soap, soap recipe
Prep Time 30 minutes
Cook Time 45 minutes
Cooling time 12 hours
Total Time 13 hours 15 minutes
Servings 9 bars
Author Lovely Greens
Cost 20

Equipment

Ingredients

Lye solution

Solid oils

Liquid oils

Add after Trace

Instructions

Prepare your Soap Making Station

  • Cold-process soapmaking is chemistry, and this recipe uses lye. Lye is a caustic substance that is completely neutralized in the soapmaking process, but it can be harmful if not handled correctly. Please read this soap making safety guidance before proceeding.
  • Ensure that your kitchen workspace is clean and set up with all of your tools, ingredients, and equipment. Please also prepare yourself by wearing long sleeves, closed-toe shoes, goggles, and plastic gloves. Soap making is fun but also chemistry so you need to work safely. I'd also advise that you make soap when smaller children aren't around put pets in a closed room somewhere. It's best to work undistracted, and you want to keep them safe.
  • Plug the crockpot in and turn the heat to high.
  • Pre-measure all of your ingredients. The solid oils into a saucepan, the distilled water into a heat-proof jug, the lye into another jug (or glass jar), the essential oils into a small ramekin, the yogurt into another ramekin, and the additional mango butter we're using as the superfat into a third ramekin.

Make the Lye Solution

  • Put on your goggles and gloves, and make the lye solution. You should do this in a well-ventilated area and try not to breathe in the steam. I like to work outisde for this step or next to an open window. Measure the sodium hydroxide (lye) into a container and the distilled water into a heat-proof jug.
  • Pour the sodium hydroxide into the water and stir very well. It will be very hot at this point so be careful. Set the jug someplace safe and leave the lye mixture to cool to around 120°F (49°C). You can set it in a sink, basin, or large bowl filled shallowly with water. If it's winter, it could be enough to set it in a safe place outside.

Melt the solid oils

  • Though you can melt the solid oils in the slow cooker, it takes a long time. To speed things up, place the pan of solid oils on the hob and turn it on to the lowest heat setting. They will melt quicker than you expect, so stay with the pan, moving the oil around in the pan to help speed up melting. When there are a few small pieces of solid oil still floating, take the pan off the heat and set it on a potholder. They'll melt with the residual heat and some gentle stirring with your spoon/spatula.
  • When completely melted, pour the oil into the slow cooker. To minimize air bubbles getting in, try pouring the liquid oils onto a clean spatula held over the pan of oils. Do this each time you add something new to the slow cooker.

Add the liquid oils

  • Next, pour the liquid oils into the slow cooker with the melted oils. Use the spatula to get every last drop out of the jug then stir the oils together gently.
  • Take the temperature of the pan of mixed oils. You're aiming for around the same temperature as the lye solution, but they can be a few degrees within 120°F (49°C)*.

Bringing the Ingredients to 'Trace'

  • When the temperatures are right, pour the lye solution through the sieve and into the oils. If you want to minimize air bubbles, set the immersion blender in the crockpot at an angle and slowly pour the lye solution somewhere along the head-end.
  • Carefully place the head of the immersion blender (stick blender) into the oils. Insert it at an angle so that any air inside the head can escape as you submerge the head. Air trapped inside the head can create air bubbles in your soap.
  • The next step, bringing the ingredients to trace, is best shown in the video at the bottom of this recipe. Have a watch to understand all the steps better, but especially this one. If you're a cold-process soapmaker, this step is exactly the same as bringing the soap to trace for that method.
  • Stir the contents of the pan gently, using the immersion blender as a spoon. Then bring it into the center of the pan and hold it against the bottom of the pan. Not moving the immersion blender, pulse for a couple of seconds. Then gently stir. Keep repeating this pulse then stir process until the soap thickens to a medium trace -- it will have the texture of warm pudding. Stop blending, tap off the immersion blender's head, and put it aside. You will not use it again.

Cooking the soap

  • The next step is cooking the soap. Turn the heat setting on the crockpot to low, and using your spatula, gently scrape all the soap residue from the sides down into the main batter. If you don't, this thin layer can turn crusty pretty quickly. Next, place the lid on and leave it to cook for thirty minutes. Do not take the lid off during this time or it will release moisture. You need your soap batter to be fluid for the next steps.
  • Over the half-hour, the soap batter will begin to puff up a bit around the edges and its texture will change. The soap in the middle will appear opaque and creamy, whereas the hotter soap on the outside will look glossier and more vaseline-like. You're aiming for all of the soap to have the glossier texture.
  • After the time is up, look through the lid of the slow cooker. If you see an opaque center still, keep cooking, and set a timer for fifteen minutes. Slow cookers vary so while it takes my model 45 minutes to cook the soap, others might take less or more time.
  • Once all of the soap batter resembles vaseline, you can turn off the heat, take the cooking vessel part out of the slow cooker, and set it on a potholder. Gently stir the outside edges towards the center and mix well but avoid stirring any crusty bits into the soap. They'll show up in your final bars as white lumps. Take the soap's temperature next. It will be very hot, and you need it to be just under 180°F (82°C) before you add your next ingredients.
    While the soap is cooling, it's best to keep the lid on the vessel. It slows down the cooling time, but it also keeps the moisture in the soap from evaporating out.
  • Just before the soap is cooled enough, melt the mango butter superfat. You can use the same pan that you used earlier to melt the other solid oils.

After the cook

  • When the temperature of the cooked soap is right, stir in the melted mango butter, the essential oil, and the yogurt. Mix it in gently but thoroughly.
  • Spoon the soap batter into the silicone loaf mold while it's still fluid. After each spoonful, tap the mold to settle the soap and to help release any trapped air bubbles. This batch should fill a 28 oz loaf mold perfectly -- the inner dimensions of mine are 8x3.5x2.5"
  • Leave the soap to cool and harden for at least twelve hours. Afterward, measure and cut the soap into bars of whatever size you'd like.
  • Though hot process soap is fully saponified after the cook, you should cure it for a full four weeks (at least) before using it. To cure your soap, set the bars on a piece of grease-proof paper (or baking paper), in an airy place out of direct sunlight. Leave the soap there to dry out and to help excess water to evaporate from the bars.
  • After the cure, use the soap or wrap it up in these eco-friendly soap packaging ideas and give as gifts. Your soap should be stored in an airy place until you use it, and to find its shelf-life, look at all of the bottles of ingredients you used. The closest date is the best-by date of your soap.
  • Watch the full video below to see step-by-step how to make simple and moisturizing hot process soap.

Notes

*Most hot process soap makers do not take the temperature for their oils and lye solution as I instruct in this recipe. However, if you do, then you can minimize issues relating to your hot process soap overheating during the cook. Overheated soap can volcano (bubble up and out of the crockpot), or even form cracks or weird textures if you mold it while it's too hot. If you're a beginner, please stick to temperatures given to ensure success.
** The video version of this recipe instructs to add all of the mango butter before the cook. However, this printed recipe instructs you to melt 5% (total weight of main soaping oils) of it to add afterward. Either way works for this recipe and your bars will be amazing. The difference is that if you add the superfatting portion of mango butter after the cook, you can be 100% sure that the superfat (extra oil) in your soap will be just mango butter. If you add all of the mango butter in before the cook, with all of the other oils, then the superfat of your bars will be a combination of all the oils used. The melting and adding a portion of the mango butter as a superfat is an extra step that is optional. Just make sure that whichever way you use, that you use the entire amount of mango butter called for in your recipe.