How to Fix Soap with Too Much or Not Enough Lye

There are two common issues people run into when making soap: not enough lye or too much lye used. Too much lye will result in a bar whose pH is too high and can cause skin irritation and burning. Not enough lye can result in oils going rancid, causing discoloration and bad odors. Both excess lye and lye deficiency can be easily fixed.

Before we dive into that however, both processes used something called rebatching. If you want a detailed overview of that, there is a post on this site with plenty of info: How to Rebatch Soap. If not, the basic steps below can tell you all you need to know.

Fixing a Batch Without Enough Lye

You need to go back to your notes and make certain there was not enough lye in the recipe. I say this because, if there was enough lye – and your oils did not saponify – there’s a good chance you have a pocket of crystalized lye that was never dissolved into the lye solution or exposed to the oils. If this is the case, DO NOT add more lye. This will just make things worse.

If you checked your recipe and realize you did not add enough lye in the original batch, do this…

1. Doublecheck your numbers by using a lye calculator. Make sure you are adding the correct amount of lye and liquid.
2. Carefully shred the soap taking the precautions needed when working with raw lye.
3. Place it in the slow cooker at low to medium heat.
4. Add about 0.5 ounces of distilled water for each pound of shredded or finely grated soap in the pot.
5. Cover and let it all melt to a gel-like consistency.
6. While the soap is melting, measure your liquid for the lye solution and put it aside.
7. Measure the lye and slowly add it to the liquid once measured. You are just making a small batch of lye solution, but you should still be very careful, working in a well ventilated area away from children and animals. And always wearing the proper safety gear.
8. Add the new lye solution into the melted soap and mix it in thoroughly.
9. Now you will complete the rebatch process as if making hot process soap.
10. Expect the unsaponified oils to react with the lye solution and mushroom, just like with regular hot process soap making.
11. Stir it down and keep watch. It will likely take 20 to 30 more minutes to finish the process once the lye solution has reacted with the oils.
12. You may only see a minimal reaction depending on how much lye was added and saponification action required.
13. The saponification process will be expedited by the extra heat of the slow cooker. But even if that were not the case, the lye solution will saponify the oils once the batter is poured into the mold. It just might take a couple days.
14. Right before the soap batter is poured into the mold is the time to add any scents or colorants.
15. Once you have the soap as you want it, pour and scoop it into the mold and let it set overnight at minimum. Bars are typically ready to cut after 12 to 24 hours.
16. Depending on the amount of extra liquid used, the bars could take between 3 days and several weeks to cure properly. There is an article on the site that can help you speed the curing process.

Dangers of Not Having Enough Lye

The first is that there was not enough lye solution to saponify all the oils, so the soap is loaded with extra oils. Usually this is done intentionally to “superfat” the soap. But what if your lye calculation was off?

Having too much unsaponified oil can be a bad thing if the amount is excessive. Two of the more common issues are the raw oils go rancid and rot within the soap. This often results discoloration and a bad small. One of the more common outcomes is known as dreaded orange spots, or DOS. This is just like it sounds; orange spots appearing on the bar that are NOT intended decoration.

Although a bit unsightly and sometimes odorous, DOS is not necessarily harmful. Having too much of slippery oils – especially those that are liquid at room temperature – is where the real danger comes in.

Olive oil, for example, is very slippery. When placed on a smooth tub surface and doused in water it is a slipping hazard waiting to happen. If there are any pockets of unsaponified oil they can melt out in patches and coat the base of the tub in a literal oil slick. That can be extremely dangerous.

So, while a little bit of extra oils can add moisturizing properties, too much can cause a slipping hazard. But don’t worry. We can fix that!

Fixing a Soap Batch with Too Much Lye

When a batch of soap has too much alkaline it is known as being “lye heavy.” This is bad because it can result in skin irritation and even cause burns.

To fix a lye heavy batch you follow most of the same steps as above – substituting the addition of lye solution for oils and fats…

Once again, return to your batch notes. This time however, you are making sure you did, in fact, put too much lye in the original natch. If you are not sure, just do a simple pH test on the cured soap. If the pH is above 9 you should try to reduce it by adding oils.

You can buy inexpensive pH paper testing kits on Amazon.com for a few dollars. Just be sure to search for “pH test strips for making soap.” These often vary form those used for testing swimming pool water, food, and other items. Types can even vary within the same manufacturer.

I have a calibrated digital pH tester now but used “Lab Rat Supplies Universal pH Test Strips” (a litmus paper type) for years and they worked great. There are plenty of other brands as well. And, plastic strips that test for a wider range of accuracy can also be found moderately priced.

I used “Lab Rat Supplies Universal pH Test Strips” (a litmus paper type) for years and they worked great.

To be clear, the saponification process is going to pick back up. The oils that you add will interact with the remaining lye to neutralize the base and make more soap. Be sure to use enough distilled water in this process to allow the lye to blend throughout the mix – especially the newly added oils.

The process to fix a lye heavy soap batch will look familiar with a few exceptions.

1. As always, recheck your oil and lye solution calculation using a lye calculator. This time it is to ensure you are adding the right amount of oil to the mix.
2. Carefully shred the soap taking the precautions needed when working with raw lye because we already know there is some raw lye in there.
3. Place it in the slow cooker at low to medium heat.
4. Carefully measure the additional oil needed and set it aside. If you are using an oil that is liquid at room temperature, leave it as is and ready to add to the pot. If you are using a solid fat, oil, or butter, melt it in the microwave or stovetop to bring it to a liquid state before adding to the pot.
5. Add the extra oil and try to blend it in. As needed, mix in about 0.5 to 1.0 ounces of distilled water for each pound of shredded soap in the pot to help evenly distribute the unused lye.
6. Just like rebatching, replace the slow cooker’s lid and let it all melt to a gel-like consistency. The saponification process is underway.
7. Now you will complete the rebatch process as if making hot process soap.
8. Expect the unsaponified oils to react with the lye solution and mushroom, just like with regular hot process soap making.
9. Stir it down and keep an eye on it in case it mushrooms again. It will likely take 20 to 30 more minutes to finish the saponification process once the previously unused lye has reacted with the oils.
10. Right before the soap batter is poured into the mold is the time to add any scents or colorants.
11. Once you have the soap as you want it, pour and scoop it into the mold and let it set overnight at minimum. Bars are typically ready to cut after 12 to 24 hours.
12. Just like with the other process for fixing soap without enough lye, the bars could take between 3 days and 3 weeks to cure fully. It really depends on how much extra water as added and how much of that burned off in the cook process.

Dangers of Having Too Much Lye

The main danger of having lye heavy soap is the damage the strong base can do to skin, hair, and your eyes. Soap with a pH of 10 + often causes skin irritation ranging from mild discomfort to painful burning sensations.

Soap is best when it falls between a pH of 7 and 9. A pH of 7 is the same as distilled water and considered neutral. This is extremely difficult to obtain in all-natural handmade soap. However, a pH of 8 to 9 is commonly achievable and a good place to be for deep cleaning soap.

Following is a pH scale indicator that demonstrates the optimal zones for pH.

That’s all for now. Happy soaping!