Hot Process Soap Recipes

Hot Process Soap was the original way of making soap. Then in modern times, the Cold Process Soap method was gradually introduced. It seems most soap makers these days prefer to make Cold Process Soaps & its popularity is everywhere.

There are very few Hot Process Soap makers these days, which makes us kind of unique, especially here in Australia. There is nothing wrong with Cold Process Soaps either, it's all about your own personal preferences. Both styles of soap wash and clean the body.

Hot Process Soaps have less issues or failures than Cold Process Soaps. When a Cold Process Soap batch fails the next step is usually followed by cooking the soap instead, this way the batch is not lost or thrown out.

Making Cold Process Soap and Hot Processed Soap use the exact same technique up until the cooking phase. The cooking process allows the soap saponification of the oils & allows the Sodium Hydroxide (Lye) to disappear, leaving only soap, which can be used the next day. The Hot Processed method cures the soap as it is cooking unlike the Cold Process method which takes 4-8 weeks to cure before the soap is ready for use and sale.

With that said, it is advisable to allow the Hot Process Soap to sit for around 4 weeks before using or selling. This time allows any excess moisture to evaporate which aids in the hardening of the soap & makes a longer lasting bar.

Hot Process Soap will result in a "Shabby Chic" or "Rustic" appearance to the final product.

You will find here Hot Process Soap Recipes and other relevant Hot Process Soap making information which is saved in PDF format. You can view, print or download them to your computer. They are free for you to use without any restrictions from our website. However, if there are conditions of use within the pages of each book, you are expected and bound to respect the owners wishes.

Slow Cooker/Crock Pot: My own personal experience is to purchase a cooker where the wattage is low. A cooker that is 3.5L usually has a wattage from between 180-250W. I have found this size cooker works well. If the wattage is above that size, it is highly likely that the soap will burn even when set on low. The cooking time for hot processed soap using this style of slow cooker is around 2 hours for a 1.3KG-1.4KG batch and slightly less time for a 1KG batch. Remember to check your soap every 15-30 minutes when your are cooking soap.

Phenolphthalein
pH testing for Hot Processed Soap

Testing the pH of your soap is an easy way to be sure that your soap is safe to use and doesn't contain any extra lye. The pH scale shows the strength of the acid/lye or base. Soap with a high pH (above 10) is likely to be too harsh, or lye-heavy, for use. When making Hot Processed Soap, testing the pH level is done in the last ½ hour of the cooking time or just when finished cooking.

Phenolphthalein is a liquid that can be applied, one drop at a time, to soap. It turns pink when it touches the soap. The darker the shade of pink, the higher the pH reading. You won't get an exact pH value, but you will be able to tell, quickly and easily, how far along the pH scale your soap is. If it turns pink, cook soap a little longer until your get a neutral (no pink colour) reading.

Phenolphthalein is also part of a swimming pool test kit. Try buying it via your swimming pool supplier, it may be way cheaper than trying to find a chemical supplier.

If you are not happy using Phenolphthalein:

Revert to doing the ‘zap’ test with your tongue instead or taste the soap – if it doesn’t taste like soap, give it more time to cook - if it tastes like soap then it’s good to go.
If your soap floats in water, then it’s usually good to go. If it sinks, it’s obviously not ready, so give the soap more time to cook.

My take is this: using distilled/demineralised water, the pH should be no issue as the water has been cleaned of impurities and the pH level should in fact be neutral. Cooking your soap to when it reaches the Vaseline stage (around 1-2 hours for 1.4KG and around 1 hour for 1KG batch), the soap should have no lye remaining. The 4-week waiting time, is mainly to give the soap time to lose more of its excess moisture and to harden.