Cutting a loaf after 4 months. How long should I cure?

[Anstarx]

I made a batch of yoghurt soap back in mid March. Poured into the mold and promptly forgot about it, so the soap just sat in the loaf mold in the room.
Some time in June I suddenly remembered that I still got this soap so I finally unmolded it. Meant to let it sit for a day to let the outside harden a bit before cutting, but lo and behold I forgot about it again.
Yesterday, I finally sat down and cut the loaf. The outside is firm but not ridig but the inside is soft to the point of clay-like. (soft recipe: only 25% shea butter as hard oil)
Now obviously I can't use it right away, it's way too soft, needs time to lose moisture. But will it be safe to use rn or should I wait the usual 6 weeks?

 

[artemis]

... usual 6 weeks?

The 6 weeks is from the day it's made. It has had it's 6 weeks. You might be surprised how quickly it firms up now that it's out of the mold.

 

[CloudShave1487]

I made a batch of yoghurt soap back in mid March. Poured into the mold and promptly forgot about it, so the soap just sat in the loaf mold in the room.
Some time in June I suddenly remembered that I still got this soap so I finally unmolded it. Meant to let it sit for a day to let the outside harden a bit before cutting, but lo and behold I forgot about it again.
Yesterday, I finally sat down and cut the loaf. The outside is firm but not ridig but the inside is soft to the point of clay-like. (soft recipe: only 25% shea butter as hard oil)
Now obviously I can't use it right away, it's way too soft, needs time to lose moisture. But will it be safe to use rn or should I wait the usual 6 weeks?

View attachment 73652

Love the way your soap looks. And the color is fantastic. If you're having a difficult time determining when the soaps will be ready, use a scale and weigh it daily. With my cold process recipes, I usually wait until the mass doesn't change telling me that all the water has more or less evaporated and the soap is ready to use.

You can try to test and use the soap as it is in its soft form, but I'd wait. Had a soft recipe much like yours, and I lost that batch.:/ Hope this helped!!

 

[AliOop]

With my cold process recipes, I usually wait until the mass doesn't change telling me that all the water has more or less evaporated and the soap is ready to use.

You can try to test and use the soap as it is in its soft form, but I'd wait. Had a soft recipe much like yours, and I lost that batch.:/ Hope this helped!!

I’m not sure how you lost a whole batch by testing one bar before full cure. Many soapers begin testing a bar very early into the cure process to see how it develops. I normally use one of the off-cut ends for this, and start testing at one week. The rest of the bars aren’t affected by this since they still sit on my curing rack.

Just to clarify for new soapers who might be reading, soap is safe to use once saponification is complete. For CP soap, that’s usually no more than 72 hours after pouring into the mold. It can be longer in some cases if the soap doesn’t firm up by then.

Whether it is ideal to use is another story. That’s where testing an off-cut really helps, especially since pH testing can’t tell you whether a soap is lye-heavy, whether it is cured, etc.

Back to @Anstarx - I can’t believe you forgot about a soap that needed cutting. For me that would be like forgetting that there is fudge on the counter, or a holiday from work. Just never going to happen!

 

[CloudShave1487]

I’m not sure how you lost a whole batch by testing one bar before full cure. Many soapers begin testing a bar very early into the cure process to see how it develops. I normally use one of the off-cut ends for this, and start testing at one week. The rest of the bars aren’t affected by this since they still sit on my curing rack.

Just to clarify for new soapers who might be reading, soap is safe to use once saponification is complete. For CP soap, that’s usually no more than 72 hours after pouring into the mold. It can be longer in some cases if the soap doesn’t firm up by then.

Whether it is ideal to use is another story. That’s where testing an off-cut really helps, especially since pH testing can’t tell you whether a soap is lye-heavy, whether it is cured, etc.

I did not mention how I lost the batch. I'm sorry if you got that from my response.

Also, for soft soaps, especially for new soap-makers who may be reading: 72 hours is a good cut-off for cure times, generally. However, for soft soaps like this one, it may be a good idea to suggest 1 month instead of the 72 hours you mentioned after molding. I started doing soft soaps, and the best advice I can give is use the methods given here in the forum that are safe, and to be patient with soft soaps, because although they have a longer cure time than other soaps, they usually will have an amazing lather after they are finished.

A soap that is ideal to use really depends on the user. Everyone has a different preference. However, it is good to set reasonable time for the soap to fully saponify. For soft soaps, I would say 1 month after molding.

Weighing out soap daily tells you that water is evaporating, and the mass of the entire soap is decreasing. When the mass doesn't change, you can be confident that the soap has finished curing. But like I said, everyone is different, and one can always wait longer. Some soaps (including one of my old recipes) needs a 1-year cure time after unmolding. I have tested castor oil soap recipes at %'s ranging from 5-50% in some recipes (not by itself), so in terms of cure time for soft soaps, especially if we are talking about using castor oil, they generally will need more time. I agree on what you said on pH paper.

 

[AliOop]

Thanks for clarifying @CloudShave1487. I think it is important to be very careful about how we use the terms "saponify" and "cure", because they are not the same. For instance, you said:

However, it is good to set reasonable time for the soap to fully saponify. For soft soaps, I would say 1 month after molding.

I really can't agree that soap needs a month to "fully saponify." Saponification refers to the chemical reaction between fat and lye, ideally resulting in no remaining lye. That process is normally complete within 72 hours for most CP soaps, and often much faster. My CP soaps are typically saponified within 12-18 hours, which I know because they are zap-free.

But I can and do agree that soap is by no means cured within that short time frame. As you stated previously, that is probably best judged by weight loss, as well as skin feel during testing. And I also agree that a good average cure time is 4 weeks, with exceptions for certain soaps like high lard, 100% OO, etc., that are better with longer cures.

Hope that clarifies, and thank you for the discussion.

 

[ScentimentallyYours]

Thanks for clarifying @CloudShave1487. I think it is important to be very careful about how we use the terms "saponify" and "cure", because they are not the same. For instance, you said:


I really can't agree that soap needs a month to "fully saponify." Saponification refers to the chemical reaction between fat and lye, ideally resulting in no remaining lye. That process is normally complete within 72 hours for most CP soaps, and often much faster. My CP soaps are typically saponified within 12-18 hours, which I know because they are zap-free.

But I can and do agree that soap is by no means cured within that short time frame. As you stated previously, that is probably best judged by weight loss, as well as skin feel during testing. And I also agree that a good average cure time is 4 weeks, with exceptions for certain soaps like high lard, 100% OO, etc., that are better with longer cures.

Hope that clarifies, and thank you for the discussion.

I just read a great article explaining the differences between cure and saponification and drying at The Ultimate Guide to Soap. Ashley Green helped me understand why Aleppo soap gets aged for so long, like cheese in caves. I still don’t understand the recommendation for curing soap in a cool place.

 

[Anstarx]

I’m not sure how you lost a whole batch by testing one bar before full cure. Many soapers begin testing a bar very early into the cure process to see how it develops. I normally use one of the off-cut ends for this, and start testing at one week. The rest of the bars aren’t affected by this since they still sit on my curing rack.

Just to clarify for new soapers who might be reading, soap is safe to use once saponification is complete. For CP soap, that’s usually no more than 72 hours after pouring into the mold. It can be longer in some cases if the soap doesn’t firm up by then.

Whether it is ideal to use is another story. That’s where testing an off-cut really helps, especially since pH testing can’t tell you whether a soap is lye-heavy, whether it is cured, etc.

Back to @Anstarx - I can’t believe you forgot about a soap that needed cutting. For me that would be like forgetting that there is fudge on the counter, or a holiday from work. Just never going to happen!

Ah well getting a new job in a new field will do that to you haha
Well defintiely let it sit for a week before testing an end piece. Guess I should've worded it as if it's as good/ideal to use as a 6 week cure piece

 

[KiwiMoose]

that would be like forgetting that there is fudge on the counter

that would NEVER happen in my house!

 

[Shelley D]

that would NEVER happen in my house!

Nor mine!

 

[AliOop]

that would NEVER happen in my house!

Neither the fudge nor the soap in my house!

 

[CloudShave1487]

I really can't agree that soap needs a month to "fully saponify." Saponification refers to the chemical reaction between fat and lye, ideally resulting in no remaining lye. That process is normally complete within 72 hours for most CP soaps, and often much faster. My CP soaps are typically saponified within 12-18 hours, which I know because they are zap-free.

We can agree do disagree on this topic. =) I just do not wish to misguide anyone here with 'general cure or saponification times'. Every soap recipe is different, and saponification times, whether cold or hot process, will be different. I studied saponification in university for my organic chemistry research module, and long story short, saponification rates are not set in stone. What oils you use, water, lye, method you use will just create a saponification rate that is unique to the recipe. Also climate.

Ah, it isn't hard to believe that we all make mistakes. And very few people are honest about the mistakes they've made much less in a forum. The brave and the few. =)

And speaking of cheese in caves, KiwiMoose, its very spot on that you said this. My shave soap is designed to be cured like this. Haha

 

[AliOop]

@CloudShave1487 How cool that you studied this in organic chem! Your street cred just went waaay up.

FWIW, I never mind being corrected and always want to admit mistakes. It's important that my mistakes aren't passed on to, or adopted by, others who read the forum.

That being said, I haven't seen any scientific sources holding that saponification (as opposed to curing) takes longer than 72 hours. If you have links to scientific sources on that point, I would love to learn more.

 

[CloudShave1487]

@CloudShave1487 How cool that you studied this in organic chem! Your street cred just went waaay up.

FWIW, I never mind being corrected and always want to admit mistakes. It's important that my mistakes aren't passed on to, or adopted by, others who read the forum.

That being said, I haven't seen any scientific sources holding that saponification (as opposed to curing) takes longer than 72 hours. If you have links to scientific sources on that point, I would love to learn more.

I'm no scientist, I just do a lot of research. I never liked jumping on something unless I knew what to expect. With that said, I have mentioned before my extensive use of castor oil. There is this scientific paper on its saponification rate here: Determination of Activation Energy of Saponification Reaction through pH Analysis | Open Access Journals

I know everyone in this forum means well here, and I would hope someone would correct me if I ever said anything incorrect or inaccurate. Saponification rates can be affected by temperature, as well as concentration of oils, and lye used. It is a chemical reaction that is not very understood.

 

[AliOop]

I'm no scientist, I just do a lot of research. I never liked jumping on something unless I knew what to expect. With that said, I have mentioned before my extensive use of castor oil. There is this scientific paper on its saponification rate here: Determination of Activation Energy of Saponification Reaction through pH Analysis | Open Access Journals

I know everyone in this forum means well here, and I would hope someone would correct me if I ever said anything incorrect or inaccurate. Saponification rates can be affected by temperature, as well as concentration of oils, and lye used. It is a chemical reaction that is not very understood.

Very interesting article, thank you! From what I read, this study was regarding olive oil, not castor. Is that correct?

With oleic acid being one of the slowest to saponify, I'd be very interested to see what other studies show for saponification rates of other fatty acids.

I'm also not entirely convinced that the pH changes are due solely to saponification. But perhaps @DeeAnna can chime in here to enlighten me.

 

[CloudShave1487]

Yes, you are right about that one. I saw oleic-oelic and idk why I thought castor. Haha =) Either way, this study is really helpful here in this discussion, because it just proves that we cannot use general guidelines for everything. And to be honest, scientific papers like these rarely come out because of lack of funding. My professor has many times stated this. The website I got this peer-reviewed article is Research and Reviews - International Journals, but NCBI is also a good source for information on the sciences. But like I said, people these days are more interested in Mars and black holes and exotic matter so I doubt we will see more information on the other oils anytime soon.

Looks like its up to us to figure it out. lol

 

[AliOop]

@CloudShave1487 actually I believe Kevin Dunn (author of "Scientific Soapmaking") has done and continues to do a fair amount of experiments. Have you read any of his stuff?

 

[CloudShave1487]

@CloudShave1487 actually I believe Kevin Dunn (author of "Scientific Soapmaking") has done and continues to do a fair amount of experiments. Have you read any of his stuff?

I am almost halfway done with the book. Its such a good read. =) I am always going back to the threads after reading a chapter. I have a lot of time. Recovering from hernia surgery really gives me a lot of time to read. Haha

 

[TheGecko]

We can agree do disagree on this topic. =) I just do not wish to misguide anyone here with 'general cure or saponification times'. Every soap recipe is different, and saponification times, whether cold or hot process, will be different. I studied saponification in university for my organic chemistry research module, and long story short, saponification rates are not set in stone. What oils you use, water, lye, method you use will just create a saponification rate that is unique to the recipe. Also climate.

I can agree with this, but we tend to use 'in general/rule of thumb' around here. As an example...it is often recommended to beginner soap makers (cold process) to have their oils and lye solution at about 110F. Why? A few different reasons...it makes sure that most oils and butters are completely melted, that if you spill your lye solution that you won't end up with a second or third degree thermal burn, and that it's an overall good temperature to soap at to ensure success. It's like advising to blend to a light-medium trace as opposed to emulsion....it about ensuring success. As with additional "Rules of Thumb"...Saponification/Unmolding time being between 24 to 48 hours based on an average size batch of between 32oz to 50oz Total Weight, and 4 to 6 weeks for curing time.

I'm in my fifth year of soap making and I still give new soap makers the same advise even as I know that you can soap at lower temperatures, that you oils and lye solution don't have to be at the same temperatures, that often times you can unmold in shorter times, and so and so forth. But it's best to build a solid foundation before you start building the rest of your house. Especially since there is so much false and conflicting information out there. Like...sure, HP is perfectly "safe" to use after it has cooled down, but it is still 'raw' soap and won't be good for your skin. Same thing with CP...the soap may be "safe" to use after 48 hours, but it's not going to be very good soap. Not only do bad soap makers reflect badly on all of us, it reflects badly on us that we don't share our knowledge (this doesn't include recipes) to make sure they are very few bad soap makers.

 

[CloudShave1487]

I can agree with this, but we tend to use 'in general/rule of thumb' around here. As an example...it is often recommended to beginner soap makers (cold process) to have their oils and lye solution at about 110F. Why? A few different reasons...it makes sure that most oils and butters are completely melted, that if you spill your lye solution that you won't end up with a second or third degree thermal burn, and that it's an overall good temperature to soap at to ensure success. It's like advising to blend to a light-medium trace as opposed to emulsion....it about ensuring success. As with additional "Rules of Thumb"...Saponification/Unmolding time being between 24 to 48 hours based on an average size batch of between 32oz to 50oz Total Weight, and 4 to 6 weeks for curing time.

I'm in my fifth year of soap making and I still give new soap makers the same advise even as I know that you can soap at lower temperatures, that you oils and lye solution don't have to be at the same temperatures, that often times you can unmold in shorter times, and so and so forth. But it's best to build a solid foundation before you start building the rest of your house. Especially since there is so much false and conflicting information out there. Like...sure, HP is perfectly "safe" to use after it has cooled down, but it is still 'raw' soap and won't be good for your skin. Same thing with CP...the soap may be "safe" to use after 48 hours, but it's not going to be very good soap. Not only do bad soap makers

I can see that. I actually like that rule of thumb for the lye and the water. That makes sense to me.

I just like to take more care when it comes to the oils in question. I'd ask you: what oils are you using? Hot or cold process? What kind of lye are you using and at what purity? You can tell me the weight, and I guess the time, but like I asked before, what oils are we talking here? So it isn't enough to say that it takes about 4 to 6 weeks, for a batch between 32 oz and 50 oz of total weight, since you're not telling me what oils are in play here.

I know you mean well, but its this exact problem I am talking about. It may work for most recipes as a "general rule of thumb", but someone out there, someone new, will read this, try it, and might not get the success they are looking for like I did. I started with using the guidelines on this forum. This is from my experience. I did not achieve the success I was looking for (some recipes), because my recipes were just a little different. If it works for most people, I have no qualms about that. But for me, in the beginning especially, I had to figure out saponification times and cure times on my own since the soaps were not performing like I thought they would after following those guidelines. Not to say that the guidelines don't work. They just didn't work for me at the time.

After running the recipes ( I call them experiments) over and over, and tweaking, one can figure out how long their unique recipe can take to fully cure, as well as being ready to use. "Scientific Soapmaking" does a great job at explaining this. In the first chapters, Kevin writes that to better understand a soap recipe, one can just make 1 bar of soap per batch, instead of wasting expensive ingredients on getting the recipe right. It allows you to better understand how the oils interact with the water-lye solution, and how your process of choice can alter the finished product. I forget who recommended me this book, but whoever did, it reminds me of being back in university.