Question for the chemists: mixing soaps for recipe experimentation

[luluzapcat]

I'm a relative newbie, exploring different recipes and looking for my favorites. I am now pondering what might be a ridiculous idea and would love the thoughts of those with expertise on just what happens to various oils during the soap-making process.

The idea:
- Make several different single oil soaps, let them harden. For example, all 100% castor oil, 100% coconut oil, etc. with lye calculated appropriately for each
- Shred these soaps
- Make a batch of another single oil soap a day later, the predominant oil for the recipe I want to test for example 100% olive oil, again with lye for this oil and batch size
- Before pouring into a mold, combine with the of the other soaps, in the proportions desired for multiple recipes I want to test. Such as one that is 50% olive oil, 45% coconut, 5% castor oil; another at 70% olive, 25% coconut, 5% castor. (I'd base my oil weights on the proportion of the portion I'm taking from my original single-oil batch, not on the weight of the soap after hardening.)

I could make a bunch of different recipes easily this way at one time, and maybe iterate more easily after trying them out, too. But--
- Is shredded soap distributed through another soap going to exhibit the same properties as soap made all at once from various oils? That's the heart of my question.

Thanks for any intelligence on this!

 

[cmzaha]

My first thought is it is a lot of work when you can do the same thing with small batches. My second thought is the fact even if soaping with 0 superfat SAP values are not exact so we cannot fully control what fats our Lye will use up during saponification, so you could still get a slight variance. Will it be a noticeable variance probably not, but why go to so much work when it is easy to make small test batches? What you want to do works well with liquid soap, but I question how well it will work for bar soap. I personally like to take the path of least resistance and a new batch is much easier than rebatching.
Here is a link to a single oil soap swap that was done a few years ago.
http://www.zensoaps.com/singleoil.htm

 

[Sony Sasankan]

I dont think it works like that. Some single oil soaps have weird results (slimy lather for example) after saponification, and I's sure they will retain those properties if you mix them with other single oil shredded soaps. I cant be sure because I haven't gone through the trouble... plus I make HP soap (counter top method), so I get almost immediate feedback on what oils in a blend does what. I think thats the best way to learn about the different oils. Once you start getting a vague sense of what you like and don't, you can lock into one recipe. Then you can go back to CP with the same recipe and play with design. No need to wait for a month to cure while you are learning about the oils... do that with HP quickly.

The lady at soapqueen did a test for single oil soaps. I found the results quite interesting and informative. Good place to start:
https://www.soapqueen.com/bath-and-...ks/single-oil-cold-process-soap-lather-tests/

 

[shunt2011]

I dont think it works like that. Some single oil soaps have weird results (slimy lather for example) after saponification, and I's sure they will retain those properties if you mix them with other single oil shredded soaps. I cant be sure because I haven't gone through the trouble... plus I make HP soap (counter top method), so I get almost immediate feedback on what oils in a blend does what. I think thats the best way to learn about the different oils. Once you start getting a vague sense of what you like and don't, you can lock into one recipe. Then you can go back to CP with the same recipe and play with design. No need to wait for a month to cure while you are learning about the oils... do that with HP quickly.

The lady at soapqueen did a test for single oil soaps. I found the results quite interesting and informative. Good place to start:
https://www.soapqueen.com/bath-and-...ks/single-oil-cold-process-soap-lather-tests/

What do you mean you get immediate feedback on what oils in a blend does what? Can you clarify? HP takes as long as or longer than CP to cure. You don't know what a recipe will truly be like until its fully cured. You can have an idea as everyone knows CO gives you lather etc...

@luluzapcat that sounds like way more work than necessary. CP is quick and easy. HP works as well depends on personal preference and what you want to do with your soap.

 

[Emmanuel]

Chemist here
In theory yes. When you create a soap, the triglycerides cuts down to single fatty acids that get saponified so in theory, a soap with 50% palmitic acid and 50% oleic acid would have the same properties , even if they come from differents soap.
In order to be sure to have a good repartition, a good stirring will be necessarry.
The only thing that could change is the crystallisation of soap during cure. Soap cristallise differently because soap molecules needs to arrange themselves relative to their neighboors. From what I know about cristallisation of soap it should in theory only impact hardness.

 

[Sony Sasankan]

What do you mean you get immediate feedback on what oils in a blend does what? Can you clarify? HP takes as long as or longer than CP to cure. You don't know what a recipe will truly be like until its fully cured. You can have an idea as everyone knows CO gives you lather etc...

@luluzapcat that sounds like way more work than necessary. CP is quick and easy. HP works as well depends on personal preference and what you want to do with your soap.

I think you are interchanging "hardening" with "curing"... which is understandable because in CP they both happen at around the same time. When you leave it to cure for a month, you are essentially allowing the saponification to happen at room temperature, and at the same time allowing the excess moisture to escape, thus hardening the bar. In HP soap, you are exponentially speeding up the saponification process by raising the temperature... and I mean warp speed level. Instead of the one month it takes for CP, the HP counter top method I use, from start to finish will result in fully saponified soap in about 20 - 25 mins. Once you have your soap in your loaf mould, HP soap sets real quick... you can take it out of your mould in 5-6 hours. You can even speed that up to 1 - 2 hours by refrigerating it. And its ready to be taken out of the mold and sliced and the bars left to "harden". 4-5 days is more than enough for HP soaps... it actually depends on how much water you used, and how much hard oils are there in the blend. But remember because this is HP soap, the airing out is just for practical purposes of having a hard bar, not for any reaction to complete. This bar can be immediately used with bare hands to check for lather, creaminess, etc.

If you are interested in the process, have your ingredients all ready just like you would for CP. Heat your oil blend to about 220 (F) and keep it at that temp. Parallely have your lye mix with water, and the hot lye solution is good to go as soon as everything is dissolved and the liquid is clear and no crystals remain. Take the oil blend out of the heat and place the pot (I use a stainless steel bowl) on the kitchen counter top. It helps to have a silicon mat or a towel placed there already, as its really hot. Pour the hot lye into the hot oil gently. Remember, everything in this process is very fast, so you have a very little window of time to work with. So you might be used to stick blending lye and oils for a while to trace in CP. In this method, trace will happen in about 3-5 seconds, and you will immediately go into the apple sauce stage. From here on its just stirring with a spatula, scrapping off the sides, etc. If all goes well, it will transition to mashed potato stage. It takes a bit of eyeballing from here. If it feels like its starting to separate, get the stick blender back and blend them back in. If it starts to be too crumbly, a few spoons of water will help blend them back in with vigorous stirring. On very rare occasions, you will be stirring and stirring, and nothing seems to happen. Usually this is when the overall temperature drops to 150 (F) or lower. Put it back at a low heat in the stove and keep stirring to bring the reaction back to speed. The problems you encounter is very specific to the oils you use and the water content. With some experience, you will get the hand of it and be a little more gutsy and try to whether this storm with as little water as possible.

Once this storm has passed, paradise awaits you in the form of a glossy vaseline stage. Saponification is complete and the soap will harden really quick. You can buy some time and also loosen the overall texture with a little yogurt / lactic acid / whey water now. It will buy you just enough time to add your superfats, essences, clays, colors, exfoliants, etc now and get them into a mould as soon as they are are incorporated. You dont have any time for aesthetics or swirls (atleast when you are just starting off and getting the hang of the pace that's required here). Your soap is done... the whole thing is about 20 minutes of stress, followed by immediate gratification Its also a breeze to clean up the pot because its already soap scrapes stuck to the spatula and the pot. Just soak them... the soap will kinda dissolve into soap water and essentially clean themselves... no need of using a scrub even... its not like the caustic oily emulsion thats left over after doing CP.

So, with this method, you can basically try out the different oil blends, and lock a favourite recipe pretty much instantly. When I was experimenting few months back, I was basically making 2-3 test batches a day, testing them the next day, then changing that day's experiments by eliminating this oil and adding more of that, etc. Give this method a try. Its ok to have a few failed batches in the beginning... Its just oil

 

[shunt2011]

I think you are interchanging "hardening" with "curing"... which is understandable because in CP they both happen at around the same time. When you leave it to cure for a month, you are essentially allowing the saponification to happen at room temperature, and at the same time allowing the excess moisture to escape, thus hardening the bar. In HP soap, you are exponentially speeding up the saponification process by raising the temperature... and I mean warp speed level. Instead of the one month it takes for CP, the HP counter top method I use, from start to finish will result in fully saponified soap in about 20 - 25 mins. Once you have your soap in your loaf mould, HP soap sets real quick... you can take it out of your mould in 5-6 hours. You can even speed that up to 1 - 2 hours by refrigerating it. And its ready to be taken out of the mold and sliced and the bars left to "harden". 4-5 days is more than enough for HP soaps... it actually depends on how much water you used, and how much hard oils are there in the blend. But remember because this is HP soap, the airing out is just for practical purposes of having a hard bar, not for any reaction to complete. This bar can be immediately used with bare hands to check for lather, creaminess, etc.

If you are interested in the process, have your ingredients all ready just like you would for CP. Heat your oil blend to about 220 (F) and keep it at that temp. Parallely have your lye mix with water, and the hot lye solution is good to go as soon as everything is dissolved and the liquid is clear and no crystals remain. Take the oil blend out of the heat and place the pot (I use a stainless steel bowl) on the kitchen counter top. It helps to have a silicon mat or a towel placed there already, as its really hot. Pour the hot lye into the hot oil gently. Remember, everything in this process is very fast, so you have a very little window of time to work with. So you might be used to stick blending lye and oils for a while to trace in CP. In this method, trace will happen in about 3-5 seconds, and you will immediately go into the apple sauce stage. From here on its just stirring with a spatula, scrapping off the sides, etc. If all goes well, it will transition to mashed potato stage. It takes a bit of eyeballing from here. If it feels like its starting to separate, get the stick blender back and blend them back in. If it starts to be too crumbly, a few spoons of water will help blend them back in with vigorous stirring. On very rare occasions, you will be stirring and stirring, and nothing seems to happen. Usually this is when the overall temperature drops to 150 (F) or lower. Put it back at a low heat in the stove and keep stirring to bring the reaction back to speed. The problems you encounter is very specific to the oils you use and the water content. With some experience, you will get the hand of it and be a little more gutsy and try to whether this storm with as little water as possible.

Once this storm has passed, paradise awaits you in the form of a glossy vaseline stage. Saponification is complete and the soap will harden really quick. You can buy some time and also loosen the overall texture with a little yogurt / lactic acid / whey water now. It will buy you just enough time to add your superfats, essences, clays, colors, exfoliants, etc now and get them into a mould as soon as they are are incorporated. You dont have any time for aesthetics or swirls (atleast when you are just starting off and getting the hang of the pace that's required here). Your soap is done... the whole thing is about 20 minutes of stress, followed by immediate gratification Its also a breeze to clean up the pot because its already soap scrapes stuck to the spatula and the pot. Just soak them... the soap will kinda dissolve into soap water and essentially clean themselves... no need of using a scrub even... its not like the caustic oily emulsion thats left over after doing CP.

So, with this method, you can basically try out the different oil blends, and lock a favourite recipe pretty much instantly. When I was experimenting few months back, I was basically making 2-3 test batches a day, testing them the next day, then changing that day's experiments by eliminating this oil and adding more of that, etc. Give this method a try. Its ok to have a few failed batches in the beginning... Its just oil

Nope not at all. Saponification takes place in 24-72 hours in CP. I'm not interchanging anything. Curing is the same if not longer in HP due to higher liquid content need to make HP. I've been making soap for 10 years.....HP and CP though I don't like making HP personally.

 

[Sony Sasankan]

@shunt2011 The saponification is pretty much done once you get to the vaseline stage in HP. Thats just a visual cue. Numerous videos on youtube actually even go to the extend of confirming it with Ph tests (and that chemical that turns red / pink if lye is still present). A lot of the water used in the HP process evaporates away with the stirring and the heat generated by the saponification thats happening as you do it. By the time you are done and pouring into the mould, there is very little water remaining. You are scooping out mac and cheese like semi wet globs instead of a thick pancake batter texture.

 

[DeeAnna]

"...The saponification is pretty much done once you get to the vaseline stage in HP. Thats just a visual cue...."

So I wonder what the gel stage in CP soap is? I'm talking about that visual cue where the soap looks dark in the center and the darkness spreads to the edges of the mold. This gel stage is complete within a few hours.

But apparently it's not the same as the gel (vaseline) stage as seen in your HP soap? Or is it?

"...Numerous videos on youtube actually even go to the extend of confirming it with Ph tests (and that chemical that turns red / pink if lye is still present)...."

Just because you've seen it on Youtube doesn't mean the Youtuber's so-called "pH test" is actually an accurate, valid test for pH.

And even assuming this "pH test" is indeed a valid test for pH, it isn't a valid test for excess alkalinty, which is the information you really want to know.

"...A lot of the water used in the HP process evaporates away with the stirring and the heat generated by the saponification thats happening as you do it. By the time you are done and pouring into the mould, there is very little water remaining....."

You are presenting an opinion with no proof to support your claim. If you really believe this to be true that "there is very little water remaining" in your finished HP soap, you owe it to yourself to actually know the facts of the matter, not just make guesses about what you think is reasonable.

The data is easy to collect. Record the weight of water in the recipe; this is the initial water weight. Saponify the soap using a hot process method and weigh the finished soap. Calculate the water loss during saponification and calculate the actual water content in the finished soap. Make the same recipe except using a cold process method and collect the same data using the same basis as best you can. Compare.

 

[CatahoulaBubble]

@shunt2011 The saponification is pretty much done once you get to the vaseline stage in HP. Thats just a visual cue. Numerous videos on youtube actually even go to the extend of confirming it with Ph tests (and that chemical that turns red / pink if lye is still present). A lot of the water used in the HP process evaporates away with the stirring and the heat generated by the saponification thats happening as you do it. By the time you are done and pouring into the mould, there is very little water remaining. You are scooping out mac and cheese like semi wet globs instead of a thick pancake batter texture.

But saponification isn't curing. I mean sure technically you can use your soap CP or HP 24 hours after you pour it but curing takes 6 weeks. Curing isn't just the water evaporation from the soap, it's the soap itself developing it's crystalline structure along with the water evaporation. And even HP soap has significant water loss after setting up. If you weigh your bars after cutting and then weigh them after 6 weeks there will be a significant loss of water weight. On top of that the way the soap performs after 6 weeks is also quite different.

 

[shunt2011]

And saponification can be done in CP in 24 hours (I gel) .....PH testing is not proof of anything other than PH. Will not test for free lye. All soap will have a high ph of 8.5-11 some more that's all PH testing does. It doesn't check for free alkali. Zap testing is the only way to check for free lye. You may want to do some more research. Also, my CP is not thick pancake batter nor is my HP semi wet globs. Curing is a totally different thing than Saponification. I think you've got the two being the same and are sadly wrong, but it's understandable if you've been getting your information from youtube.

 

[amd]

Regarding the OP's original topic... I've run this scenario past my IRL chemist friends (I'm lucky enough to have two of them in life), and they're on the fence. The idea would give you a general idea of soap performance, but they think you would be missing some of the subtleties (there was much talk of lattices and layering, my eyes glazed over and there were space kitties on donuts... so forgive my paraphrasing to "subtleties") of the formation of soap as one blended unit. As pointed out by Carolyn, the lye will take what it wants to take, so a slower saponifying oil might be more present as SF in a finished blended soap, but not the same balance in the shredded soap. These seemed to be a concern by John and Mel (my chemists) as well. Also, soap gets better as it ages, so if your shred testing has any difference in age - say several weeks to months - that difference of cure time between the shreds and the fresh base will also affect your soap result. I think many of us see this difference in confetti soaps - they seem to be so much nicer than our usual cured soaps. I think this is because we may be using older, well aged scraps. So... would you get the same results from the shredded soap tests as a fresh batch made with the same recipe? No. But you will get a very general idea using the shredded method... but not spot on.

After discussing, and processing it through myself... I think I would mix up each soap recipe in a small batch so that I can really see how it performs, cures, and changes over time. Shredding and maths, and the variations involved in the shred method really seem like more work. Label and document well (typically when I do tests on several recipes at once I will use different colors to help me quickly identify "which soap is this again").

 

[luluzapcat]

Thanks everyone here for the thoughts and discussion (and to amd's chemist friends!). Sounds like the consensus is it will be informative but not definitive. And the point that soaps would need to be made at the same time for a real true comparison makes this less appealing than I initially thought. I was hoping I could have a "stable" of soaps from the ingredients I am especially interested in (experimenting on vegan/sustainable/economical!) and recombine them various ways over time--but the fact that I'd want to add them into one newly poured soap batter would really mess with that balance of cure times.

The original "inspiration" (devil on shoulder?) for this idea came from washing my hands with a couple of soap scraps at once that were by my sink, one lard and one olive oil. Maybe that's actually a better way to fool around with this! Although impossible to control proportions, so maybe not.

Ok, looks like many small batches are in my future!

 

[amd]

The original "inspiration" (devil on shoulder?) for this idea came from washing my hands with a couple of soap scraps at once that were by my sink, one lard and one olive oil. Maybe that's actually a better way to fool around with this!

I know exactly what you mean! I throw my small soap slivers into a crochet bag to continue using them. These bags are a combination of my soaps and other people's soaps, so when I use the soap bag in the shower it tends to be quite different (in a good way) than the original soap experience. I always think to myself... if there were a way to record which soaps went into the bag and their recipes... would I be able to recreate a recipe that behaves just.like.this... and then I start way overthinking it with "well, then I'd need to know what size each sliver was so I could get the correct ratio and I'd have to figure out other people's formula..." and on it goes until there's space kittens riding donuts.

I've been there with the testing in small batches. I did that for about a year, one batch at a time, until I found the winner... and then tweaked it a year later... and tweaked it the year after that... Enjoy the process!