Sooner or later, you will come to the point where it seems as if you are waiting forever for your soap to get hard enough to remove from the mold. Most often even after removing it from the mold there is an even longer wait until it gets hard enough to cut hence learning how to harden cold process soap faster comes in handy.
Finding ways to harden cold process soap to be hard enough to remove from the mold or to cut no matter your recipe will be invaluable to your soap making skills.
There are three ways to harden cold process soap faster. Add salt, add sodium lactate and use a water/liquid discount.
The beauty of these three major options is that you can either employ all three or just one at a time to meet a desiered result. However you must take note that there are some precautions you MUST take into account.
Adding salt to harden cold process soap faster.
Salt has long been a known additive that can harden any cold process soap quickly. However it can be used in two ways.
The first technique of adding salt to your soap is the one that you may be more interested it. This is where you add just enought salt into your recipe to help the bar harden quickly without making it super hard.
NOTE: Add the salt to your lye water mixture not your oils
The second technique is adding enough salt to make a salt bar. This will result in an extreemly hard bar of soap, one so hard it becomes difficult to cut.
Lets talk about adding enough salt to harden your cold process soap faster. To do this is quite simple, add 1/2 teaspoon per pound of oils used in your recipe. In soap making most everything is based on the weight per pound.
This means for an average 48oz mold which requires 320z of oil you will use 1 tea spoon of salt to your lye water mixture.
So the second quesiton you may be asking… what type of salt is the best type of salt to use for this technique. Great question. Regular table salt works well however I have notice a slight difference when using table salt vs sea salt.
Sea salt is best for a salt bar as its unrefined and in its purest form. Table salt has some refinement but not so much that it takes away from its purpose in the soap making process. For this purpose… table salt works just fine.
Be aware of your soap batter trace
When adding salt to your soap, it can react with other chemicals in your soap batter and cause your soap to thicken pretty quickly.
I find that using a whisk to stir the lye water and oils together will give a better idea of how fast the soap batter will thicken.
Keep in mind the use of certain fragrances can cause your soap batter to thicken quickly hence adding salt will only make it worse.
Stir your lye water and oil with a whisk and watch if it begins to thicken or if it remains liquid enough to stick blend.
Use your stick blender to combine the lye water and fats to avoid ricing or even separation.
Adding sodium lactate harden cold process soap faster.
Sodium lactate may seem redundant to adding salt to your soap recipe. This is because sodium lactate is often confused with being actual salt because they share the same name…sodium.
Sodium lactate and sodium chloride are not the same, sodium chloride is table salt while the sodium lactate is a biproduct of actual sodium salt of lactic acid a liquid form sourced from plant material.
No matter the name it is the sodium that does the work of hardening your soap faster.
Add 2 teaspoons of sodium lactate to your lye water and stir. The best practice for this is to add 1 teaspoon of sodium lactate per pound of oils.
A typical 42oz soap mold will accept 32oz of oils/fats hence 2 teaspoons of sodium lactate is sufficient.
The sodium lactate actually helps the soap harden faster and makes it easier to remove from the mold especially when you use a majority of soft oils in your recipe.
Sodium lactate caution
It may seem sensible to add more than 2 teaspoons to your mixture however just like adding pure table salt will change the composition of the soap making it very hard the same can happen with sodium lactate.
Reports have stated that loading your soap with sodium lactate to make your soap harden faster will work but a side effect is that sometimes it makes your soap either brittle or oily.
Why so inconsistent? We do not know at this time. Its best to stick to the recipe unless you are ready to take on an experiment to find out otherwise.
Learn more about sodium lactate HERE.
Use of a water/liquid discount to harden cold process soap faster.
A water discount when making your lye water is one of the easiest ways to ensure that your soap harden faster however it requires careful planning.
When making or using a soap recipe, the lye water is made with just the right amount of lye to convert fats into soap but it needs a medium to help bind the two chemicals together.
This is where the water in your lye water comes into play. Having the right amount of water to ensure the lye dissolves properly is key to good lye water.
Most recipies use a bit more than enough water to ensure the lye dissolves easily into the water, but this can be changed.
Having less water means that there is less water for the lye to dissolve into and as a side effect it makes the heat generated much hotter than usual. We have seen temperatures reach over 200° F when using a water discount.
Be careful of how much of a discount you use.
Not only does the heat generated during the combining of water and lye but its corrosiveness and danger increases.
Your soap still requires the water to help combine the lye with the oils. With a water discount, chances are you will reach a medium or thick trace even faster.
Think of this quick trace combined with a fragrance that already causes accelerated trace. Within seconds you soap will begin to thicken up. It’s a recipe for disaster.
Conclusions on how to harden cold process soap.
When it comes to making a hard bar of soap, it is often left up to the type of oils use. As coconut oil wil produce a harder bar of soap than olive oil.
Learning the combination of oils that make a good stable bar of soap is important. However, knowing how to make a hard bar of soap faster is invaluable when you are running a small business.
The use of salt, sodium lactate or water discount will all help you make a harder bar; however, it often comes with a few caveats and side effects of each.