Help! Is my soap Lye Heavy?

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cosmicomic

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Hello all!

Im in a bit of a situation. I poured a large batch of 6 loaves yesterday and the container that I used filled up pretty much to the brim and my spatula didn't fully reach the bottom. But while blending the oils and lye, i did use the stick blender which did reach the bottom and blended it to a thin trace (I needed a thin trace for the design) The pour went off as planned and everything seemed ok. But while unmoulding the soap today I found big cracks only in the top of the soap, which I've never had before. And while cutting the soap, it seemed the slightest bit crumbly but just on the top layer. the bottom two layers seemed absolutely fine. So i decided to do a zap test and found that the top layer did zap me while the bottom two didn't.
So I'm really confused about what to do! Im certain I used the correct recipe and didn't miss out on any oils or butters. I always check the total weight of the oils and it was correct. I also used a 3% superfat on this batch so id assume that that would take care of any excess lye. But why was the top crumbly then? How can I know if the soap is lye heavy or not? Is it possible that the saponification is still taking place and the lye just needs to blend into the bottom bits? And is there any way that I can salvage these soaps?

thank you so so much!!
 
Yes!
5% Castor Oil
5% Sweet Almond
30% Olive Oil
35% Coconut Oil
5% Cocoa Butter
10% Shea Butter
10% Kokum Butter
35% Lye Solution with 3 % superfat

Process: I soap at room temp, so i melted down the butters mixed the hard and soft oils. the temperature was 87F, lye was a similar temp. I mixed the whole batch in and stirred, first with the spatula, soon realising i may not be able to mix correctly I used the stick blender. and mixed it up. When it appeared as though it was at light trace, I added the fragrance oil blend, mixed some more. Then I took a jug and poured out what i needed to make the first layer into another container. Because I felt like it may still not be well mixed, i poured it back into the main container, stirred some more and finally took what i needed for the layers.. I proceeded to make the layers- 2 layers followed by a line pour for the third layer. that's it. I also used gold mica with a lot of oil, so that oil too is in there in between the likely to be lye heavy layers.

Hope this helps!
 
The percentages of fats don't add up to 100%. I didn't run your recipe through a recipe calc because it wouldn't make any difference -- not only is that missing 10% an issue, but I'd need to know the actual weights of fats and lye you used to verify the batch formulation, not just percentages from your recipe worksheet. So ... next time, use weights for ALL ingredients. No percentages. No mixed weights and percentages.

Also, is it 35% lye concentration or 35% water as % of oils? There's no "lye solution" setting in any of the soap recipe c@lcs I'm familiar with, but there is lye concentration and "water as % of oils" and people confuse the two fairly often. I know this sounds picky, but you wouldn't believe how many times this has caused problems when people ask for help here.

Anyways, if your soap is newly made, give it a few days to a week before you test again for excess lye. Small amounts of excess lye will disappear if given some time for the chemical reactions to happen.

Why the top tested lye heavy but the bottom didn't - I'm guessing what is now the top layer of your soap was the last part of the soap batter. It's normal especially when using batter that's only at emulsion or light trace, for the last of the batter to be slightly lye heavy compared to the first part of the batter. The batter is just barely emulsified and sometimes it tends to separate slightly.

Next time before you pour the batter, first scrape the bottom and sides of the soap pot with a spatula (not a whisk, not with the bell of the stick blender) and mix those scrapings into the soap batter. This will ensure all of the batter is evenly blended and the batter is as consistent as possible.

edit:

Also at 87F, you might be soaping a bit too cool for the solid fats in your recipe. It's hard to say for sure -- this temp might be fine for your recipe. If your fats aren't visually clear when you start making the soap batter, you might see stearic spots (white spots) in the finished soap and/or you might see false trace when mixing the batter. Hard to say if either one will be a problem for you ... just something to keep in mind.
 
Last edited:
It is impossible to tell at this point. You did not give the weight of the entire batch. This could be 6 lbs or 25 lbs total weight or even larger. But you do mention very light trace. If your last layer was a very thin trace when you poured it may have taken longer to saponify or if you insulated well it may have overheated and cracked. Light/thin traces can also be prone to heavy crumbly ash. I would simply give the soaps a long cure and see if the zapiness go away which I am guessing it will. Light/thin trace soap batter can easily zap for 72 hrs. This I know for a fact since I normally poured and just emulsion. Sorry, I am not a lot of help here. Once you demold, if your block weighs out correctly including all your ingredients for a total batch weight I would say it will be fine after a good cure time.

ETA: OOPS I did not read DeeAnna's post before posting. Please follow her recommendations.
 
The percentages of fats don't add up to 100%. I didn't run your recipe through a recipe calc because it wouldn't make any difference -- not only is that missing 10% an issue, but I'd need to know the actual weights of fats and lye you used to verify the batch formulation, not just percentages from your recipe worksheet. So ... next time, use weights for ALL ingredients. No percentages. No mixed weights and percentages.

Also, is it 35% lye concentration or 35% water as % of oils? There's no "lye solution" setting in any of the soap recipe c@lcs I'm familiar with, but there is lye concentration and "water as % of oils" and people confuse the two fairly often. I know this sounds picky, but you wouldn't believe how many times this has caused problems when people ask for help here.

Anyways, if your soap is newly made, give it a few days to a week before you test again for excess lye. Small amounts of excess lye will disappear if given some time for the chemical reactions to happen.

Why the top tested lye heavy but the bottom didn't - I'm guessing what is now the top layer of your soap was the last part of the soap batter. It's normal especially when using batter that's only at emulsion or light trace, for the last of the batter to be slightly lye heavy compared to the first part of the batter. The batter is just barely emulsified and sometimes it tends to separate slightly.

Next time before you pour the batter, first scrape the bottom and sides of the soap pot with a spatula (not a whisk, not with the bell of the stick blender) and mix those scrapings into the soap batter. This will ensure all of the batter is evenly blended and the batter is as consistent as possible.

edit:

Also at 87F, you might be soaping a bit too cool for the solid fats in your recipe. It's hard to say for sure -- this temp might be fine for your recipe. If your fats aren't visually clear when you start making the soap batter, you might see stearic spots (white spots) in the finished soap and/or you might see false trace when mixing the batter. Hard to say if either one will be a problem for you ... just something to keep in mind.
Thank you so much for your detailed response! And sorry for not sharing the weights. The entire batch was a 5400gm batch of oils. I also just checked the recipe and it is correct, i.e not missing 10% fats. Unfortunately, I don't have the exact amounts in gms on me, it is at the studio I work out of. I could run it through soap calc and send it across.
Also I meant a 35% lye concentration sorry about that :)

Thank you, I will wait to find out how the soap is doing, fingers and toes crossed that the chemical reaction will sort it out.

thank you for all your tips!! i will definitely do the scraping and mixing the next time I do this. Im used to pouring 3600gms of soap regularly. This is the first time I'm doing a larger batch and I'm guessing I didn't have the appropriate tools, a long enough spatula etc.

Regarding the temp, Ive not had a problem as such, most of my batches turn out fine, but I will try soaping a little warmer next time to see how they turn out!

It is impossible to tell at this point. You did not give the weight of the entire batch. This could be 6 lbs or 25 lbs total weight or even larger. But you do mention very light trace. If your last layer was a very thin trace when you poured it may have taken longer to saponify or if you insulated well it may have overheated and cracked. Light/thin traces can also be prone to heavy crumbly ash. I would simply give the soaps a long cure and see if the zapiness go away which I am guessing it will. Light/thin trace soap batter can easily zap for 72 hrs. This I know for a fact since I normally poured and just emulsion. Sorry, I am not a lot of help here. Once you demold, if your block weighs out correctly including all your ingredients for a total batch weight I would say it will be fine after a good cure time.

ETA: OOPS I did not read DeeAnna's post before posting. Please follow her recommendations.
Thank you so much for your response! the entire batch weight was 5400gms. I should have checked the block weight, I didn't do that. Heres me hoping it saponifies further and the zapiness goes!! will check again in 4-5 days :)
 
Hello all!

Im in a bit of a situation. I poured a large batch of 6 loaves yesterday and the container that I used filled up pretty much to the brim and my spatula didn't fully reach the bottom. But while blending the oils and lye, i did use the stick blender which did reach the bottom and blended it to a thin trace (I needed a thin trace for the design) The pour went off as planned and everything seemed ok. But while unmoulding the soap today I found big cracks only in the top of the soap, which I've never had before. And while cutting the soap, it seemed the slightest bit crumbly but just on the top layer. the bottom two layers seemed absolutely fine. So i decided to do a zap test and found that the top layer did zap me while the bottom two didn't.
So I'm really confused about what to do! Im certain I used the correct recipe and didn't miss out on any oils or butters. I always check the total weight of the oils and it was correct. I also used a 3% superfat on this batch so id assume that that would take care of any excess lye. But why was the top crumbly then? How can I know if the soap is lye heavy or not? Is it possible that the saponification is still taking place and the lye just needs to blend into the bottom bits? And is there any way that I can salvage these soaps?

thank you so so much!!
Cracks are usually caused by overheating which can also cause the top of the soap to be a bit 'crumbly', and the 'crumbly' could also be a Soda Ash which is caused by the lye reacting to the carbon dioxide in the air.

Since the top layer would have been the last layer poured and would have also been poured after the other layers had set, it would be logical since you had such a thin trace, for it to be last layer to go through saponification.

And speaking of saponification...you don't mention how long after you made the soap you unmolded. Just because your soap is hard enough to unmold after say...12 hours, 18 hours...does NOT mean that it is fully saponified. While the saponification is usually complete within 24 to 48 hours, there are factors like temperature, humidity and a thin batter that can extend it another 24 hours.

Let it set for a couple of days and then retest it.
 
Cracks are usually caused by overheating which can also cause the top of the soap to be a bit 'crumbly', and the 'crumbly' could also be a Soda Ash which is caused by the lye reacting to the carbon dioxide in the air.

Since the top layer would have been the last layer poured and would have also been poured after the other layers had set, it would be logical since you had such a thin trace, for it to be last layer to go through saponification.

And speaking of saponification...you don't mention how long after you made the soap you unmolded. Just because your soap is hard enough to unmold after say...12 hours, 18 hours...does NOT mean that it is fully saponified. While the saponification is usually complete within 24 to 48 hours, there are factors like temperature, humidity and a thin batter that can extend it another 24 hours.

Let it set for a couple of days and then retest it.
Hi there! thank you for your reply. Sorry i forgot to mention how long after I unmoulded. I unmoulded them after 48 hrs. But the good news is that the soaps are already appearing less crumbly. Im yet to do a proper ph test and the zap test but I'm hoping its all good by then. fingers crossed!
 
About testing pH -- there's nothing wrong with checking the pH, but people think the pH can tell them more about their soap than it really does.

It's more important to know if your soap has excess alkali (lye heavy) than it is to know the pH, to be honest.

The zap test is a quick test for excess alkali. The pH test is not -- it is quite possible to have a soap with a given pH that is NOT lye heavy and another soap with the exact same pH that IS lye heavy.

There is an accurate, industry accepted test for measuring excess alkalinity, but few of us small soap makers are set up to do it. This test requires a sample of soap to be neutralized with an acid and the excess alkali in the soap is calculated from the amount of acid needed for neutralization.
 

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