So discouraged about unincorporated lye

[Tuftyloves]

I’ve been making and selling soap for two years and now and all of a sudden I’m having issues with unincorporated lye. The bars as a whole feel great and normal so I know it’s not a problem with my recipe (it’s been my tried and true for over a year) but I get unincorporated lye all of a sudden! Like they’ll take forever to set up, and then the outer layer of the soap is super crunchy and hard and zaps. Or I’ll get an oozy lye pocket while everything else seems fine.

Had anyone else dealt with this?! Am I getting too lazy about stirring my lye into the water? Not blending well enough? I’m so confused and so so discouraged.

 

[DeeAnna]

I'm not sure I see any problem -- your photos show soap that looks fine to me. Since you've not shared info about your recipe and method, I can't offer advice or suggestions for improvement about those aspects of your soap making. In particular, you wonder if you're blending enough, but how do we know if you did enough or not if we don't know what you actually did?

The white soap has a rind of lighter color around it. Most of the time that's due to a color change from exposure to the open air. Usually the entire surface of the soap will become entirely the color of the rind (whiter in this case) after some days. The lavender and green soap shows stearic spots or air bubbles or both. Hard to say which from the photo.

If you have ash on the outside of the soap, it can give you a mild to moderate zap even if the actual soap does not zap. Ash is not "unincorporated lye" however, and it doesn't mean your soap is bad. Just ashy. If you actually have a speck of solid NaOH in your soap and you zap test that spot, I guarantee you will get an unbelievably strong and unpleasant zap and a near-instant burn.

You should be able to tell if the NaOH in your lye solution is fully dissolved or not -- pour the lye solution through a strainer when you add it to the fats. If there's solid NaOH, it will stay behind in the strainer. Once dissolved, NaOH cannot un-dissolve itself again into solid particles, so that is a non-problem.

 

[Tuftyloves]

I'm not sure I see any problem -- your photos show soap that looks fine to me. Since you've not shared info about your recipe and method, I can't offer advice or suggestions for improvement about those aspects of your soap making. In particular, you wonder if you're blending enough, but how do we know if you did enough or not if we don't know what you actually did?

The white soap has a rind of lighter color around it. Most of the time that's due to a color change from exposure to the open air. Usually the entire surface of the soap will become entirely the color of the rind (whiter in this case) after some days. The lavender and green soap shows stearic spots or air bubbles or both. Hard to say which from the photo.

If you have ash on the outside of the soap, it can give you a mild to moderate zap even if the actual soap does not zap. Ash is not "unincorporated lye" however, and it doesn't mean your soap is bad. Just ashy. If you actually have a speck of solid NaOH in your soap and you zap test that spot, I guarantee you will get an unbelievably strong and unpleasant zap and a near-instant burn.

You should be able to tell if the NaOH in your lye solution is fully dissolved or not -- pour the lye solution through a strainer when you add it to the fats. If there's solid NaOH, it will stay behind in the strainer. Once dissolved, NaOH cannot un-dissolve itself again into solid particles, so that is a non-problem.

Thank you for your super thoughtful reply!
I should have described the photos better. On the white one, that white ring around the outside is extremely brittle and does zap. And then on the purple and green one, there is a weepy lye spot that might not be showing up very well.

I will definitely start straining and blending for an extra minute.

It’s just disheartening because I don’t know what I’m doing wrong.

 

[DeeAnna]

I don't have an answer about the zappy rind. This is probably related to your recipe or your method.

As far as the weepy spot, I'm not surprised to learn its alkaline (zappy), but everyone assumes it's "lye" as if the lye solution somehow remains independent of the other liquids in the soap. It might be due to an excessive amount of fragrance in the soap. Or fragrance or other liquid additive that was added at trace. Again, I know nothing about your recipe or your method, so just guessing here.

 

[hanaherrera]

I don't have an answer about the zappy rind. This is probably related to your recipe or your method.

As far as the weepy spot, I'm not surprised to learn its alkaline (zappy), but everyone assumes it's "lye" as if the lye solution somehow remains independent of the other liquids in the soap. It might be due to an excessive amount of fragrance in the soap. Or fragrance or other liquid additive that was added at trace. Again, I know nothing about your recipe or your method, so just guessing here.

This is interesting! I'm one of those who assumes that

I'm a novice soap maker, having started only late last year. I started with melt and pour but then became fascinated with cold process designs and ingredients posted by soap makers in socials. I have weepy spots in my freshly cut tomato soap, which I made about 5 days ago if i remember correctly. It's just recent. I never noticed the spots in my previous batches and I am just about to use up a soap bar from my first batch when I began to feel a pinch or a sting and then following that, an itch on the arm.

I've been searching the web for similar experiences and answers to why and how batches like mine can be fixed. I posted in one of the facebook groups and someone suggested rebatching. I also posted on one of the soap making hobbyists' youtube and the response was the same, rebatch.

So now, I'm reading about rebatching stingy zappy soaps, and also how to make them fluid so they won't look crumbly...

So, if I understood your comment correctly, you mean the lye solution will always bond with the oils in a batch, and there will never be free floating ones that didn't find an oil match? Provided that all the weighing measurements are correct. Forgive me, it's feb 14 and I'm likening the lye solution and oil bond to a pair of lovers just so I can picture the bond in my mind.

And the alkaline weepy spots on the cut surface of the soap is actually from the fragrance oil?

I bought some books at amazon, i feel like i'll learn more here...

 

[DeeAnna]

...you mean the lye solution will always bond with the oils in a batch, and there will never be free floating ones that didn't find an oil match?...

Nope, I didn't want people to think either of these things. I regret I wasn't clear enough -- let me try again --

There can most definitely be excess alkali in soap. The excess alkali can be a temporary problem that resolves itself with time. Or it can be a permanent problem that perhaps can be corrected, typically by rebatching. Sometimes the problem is bad enough the soap really needs to be discarded, however.

A few reasons why soap can contain excess alkali -- if saponification isn't quite finished (likely your problem), if the soap maker chills the soap so much the cold really slows saponification down, if the soap maker makes a measurement error and adds too much alkali, if the amount of mixing is not sufficient to intimately blend the fats and alkali to ensure full saponification, if the soap overheads and the batter separates, etc.

Soap can be temporarily too alkaline (zappy) to be skin safe if you test the soap in the first few days after it's been made. This is especially a problem if you soap at cool to cold temperatures. Newer soap makers tend to leap into rebatching soap with a temporary excess of alkali like this, but if a person can muster the patience, the problem often resolves itself with time. I suggest people wait a week or so before testing their soap -- it's very likely a soap that is slightly zappy at first will be fine after a few days.

Soap can be permanently too alkaline if you use a lot more alkali than the fat can consume during saponification. Or if the soap emulsion fails and the soap batter separates in the mold. This is when a rebatch can be useful to correct a serious problem.

***

Once NaOH is dissolved, it will not not magically turn solid again in the lye solution. If you KNOW your NaOH is fully dissolved and liquid when you poured it into your soap batter -- say you pour the lye solution through a strainer when you add it to the fats -- there simply won't be any solid NaOH particles in the soap. If you do see solid particles in the soap batter or the finished soap, the particles are something other than solid NaOH.

It might be possible for solid NaOH particles to be in the finished soap if something happens so the alkali can't dissolve properly before it is poured into the soap batter or the soap maker doesn't check to ensure the alkali particles are fully dissolved.

This problem can happen if the soap maker tries to chill the water or the lye solution too cold, so the NaOH can't dissolve properly. Or theh soap maker gets in a hurry and doesn't stir the NaOH particles so they remain loose and floating in the liquid so they can dissolve easily. Or the soap maker doesn't allow enough time for the particles to fully dissolve. Or they make the lye solution with an opaque liquid like milk. Or they get in a hurry and use the lye solution without checking first for solid particles in the bottom of the lye pitcher. In these instances, I can see larger particles surviving in the soap to cause problems later on.

***

Before the alkali fully reacts with the fats or with the carbon dioxide in the air, any liquid weeping out of the soap is very likely to be alkaline (high pH) but that liquid isn't JUST lye solution.

The weeping liquid is a mixture of all the water-based liquids that went into making the soap. We add a variety of water-based liquids to soap -- lye solution, sometimes sodium lactate, food purees, and other water-based additives. And there's also the glycerin produced from saponification which is also water soluble. Each of these water-based liquids doesn't float around the soap as an individual blob, they all get mixed together into a whole. This mixture of water-based liquids is what weeps out of soap, not just the lye solution.

Sometimes soap makers add fragrance or other hydrophobic liquids at trace. (Hydrophobic = "water hating." In other words, liquids that don't mix with water.) Sometimes the soap maker doesn't get the fragrance intimately mixed into the soap batter due to lack of time, or due to the soap batter getting too thick, or whatever. If this happens, droplets of the fragrance can weep out of the soap later. Even in this case, the liquid isn't usually just fragrance. Some water-based liquid usually also weeps out with the fragrance. The result is these weepy areas can be strongly alkaline (very zappy) at first until the alkali reacts with the CO2 in the air.

 

[KiwiMoose]

@Tuftyloves - do you use sodium lactate in your soap? Sometimes the brittle edges can be caused by sodium lactate.

 

[hanaherrera]

A few reasons why soap can contain excess alkali -- if saponification isn't quite finished (likely your problem),

I appreciate your reply . I soap at room temperatures and for me that's about 25-30 degrees here in my country. For now it's somewhere between 25-27 and it'll get hotter in March. I use my shop's storeroom to soap since I have an exhaust fan there and a sink nearby. I leave my soap molds there overnight without insulating them. But I do cover the tops with a wooden lid or cardboard if the mold doesn't have a lid of its own. And after I unmold and cut after 24 hours, I move the bars to cure on a rack in my shop where there's an ac unit that cools the room to 20 degrees... could this be the reason why my bars still have excess alkali? That perhaps, the change in room temperature has disrupted saponification and my bars aren't drying as they're supposed to?

if the amount of mixing is not sufficient to intimately blend the fats and alkali to ensure full saponification,

I suspect that this is me too when I have shea and cocoa butters and both are at 10% of my recipe. I noticed that my batter thickens up so fast that I feel that I haven't blended enough and I still have to mix in the fragrance... so I hurriedly pour in the fragrance and mix briskly so I won't end up with soap on a stick

Newer soap makers tend to leap into rebatching soap with a temporary excess of alkali like this, but if a person can muster the patience, the problem often resolves itself with time.

Now I understand why we need to cure at 4-8 weeks, and sometimes 4 weeks is not enough. I took a bar from the first batch that I made and used it when it had just cured for 4 weeks. That's the bar that I referred to previously, that caused an itch. I left that one to dry awhile and I tried to use it again yesterday, and it was fine again.

But I did rebatch the one I made with tomatoes just this Saturday (yep, i'm impatient and I was excited to jump into my first rebatch experience ). It's still quite soft like clay and a little sticky maybe because I added a tsp of glycerin. It has dried a bit and I was able to stamp on it so I'm hoping it'll firm up more. Otherwise I will have to reduce the amount of water (2 ounces) I used in my next rebatch.

If you KNOW your NaOH is fully dissolved and liquid when you poured it into your soap batter -- say you pour the lye solution through a strainer when you add it to the fats -- there simply won't be any solid NaOH particles in the soap.

I leave my lye solution to cool while I prepare my oils. I actually leave it for like an hour or two while preparing my oils. Sometimes, I put my stainless jug in a cold water bath so the lye solution cools down faster. Please tell me that's not good practice.... The straining, I will have to remind myself to do that. I often see soapmakers do that in their videos, like the Norwegian soapmaker I follow on youtube, she strains her lye solution while pouring in her oils.

It might be possible for solid NaOH particles to be in the finished soap if something happens so the alkali can't dissolve properly before it is poured into the soap batter or the soap maker doesn't check to ensure the alkali particles are fully dissolved.

This problem can happen if the soap maker tries to chill the water or the lye solution too cold, so the NaOH can't dissolve properly. Or theh soap maker gets in a hurry and doesn't stir the NaOH particles so they remain loose and floating in the liquid so they can dissolve easily. Or the soap maker doesn't allow enough time for the particles to fully dissolve. Or they make the lye solution with an opaque liquid like milk. Or they get in a hurry and use the lye solution without checking first for solid particles in the bottom of the lye pitcher. In these instances, I can see larger particles surviving in the soap to cause problems later on.

Omg. So if I let my lye solution sit overnight and use it the following day, would this ensure that all of my sodium hydroxide beads have fully dissolved? I often use a lye solution strength of 33-35%

I like the way you explained all these soaping concepts. Appreciate this so much!

 

[DeeAnna]

Letting the lye solution sit until cool or overnight will help ensure the alkali is fully dissolved, but if you don't stir when you first mix the dry alkali with the water, the alkali can form larger solid clumps in the bottom of the container. Those lumps will not dissolve well -- just like if you put dry flour in boiling liquid, the flour will make clumps that don't go away no matter how long you simmer the liquid. Stirring is pretty important.

Another issue about letting lye solution sit is it needs to be in an airtight container to prevent it from absorbing water from the air and reacting with carbon dioxide in the air. If you don't store it properly, your lye solution will lose its strength. Don't seal the container tightly until after the lye solution cools down, though, because pressure can build in a tightly closed container of hot liquid, and you don't want that.

You can cool the lye solution in cold water, but I don't recommend cooling lye solution below about 65 F / 22 C because the dissolved alkali can crystallize out of solution if it gets too cold. This is especially true for lye solutions of 33% concentration and more concentrated.

If you're making lye-based soap from scratch using fats (as opposed to making soap using fatty acids), I don't recommend adding glycerin. Lye-based soap made from fat will naturally contain about 8% glycerin by weight that is created by the saponification reaction. Adding even more glycerin raises risk of the soap being permanently soft.

Be careful that any food (tomato) or other botanical material you put in your soap is pureed into fine particles. Larger chunks of any food added to the soap or used as a topping on soap can easily become moldy.