Tentative query about castor oil and soda ash - Becoz it can't be true!

[JuliaNegusuk]

Wow. Really good video. From that low water and thicker trace seem to potentially be the answers. I don't usually worry too much about trace, as I think someone has mentioned. I will give it more attention. But cavity moulds are a bit trickier to fill with thick trace. But not impossible do I'll see how I get on. Really recommend video, very useful, very clear, thanks.

 

[Rogue-Soaper]

So challenging trying to pin down the culprits! I use 5% castor oil, a must for me, and don't get soda ash. I got soda ash once in my beginning days. Now I pour, spray with rubbing alcohol, cover with plastic wrap, cover with cardboard, and then several towels to gel -- and haven't gotten ash since. Best wishes!

Same here.

 

[linne1gi]

I have been having a helluva time with soda ash on a certified recipe (I am in UK). I have tried CPOPing which is mostly successful but does rather spoil the colours of a couple of my soaps as I use natural colours. Ash has only been a problem on about 4 of my 9 regular recipes. The base recipe is identical in 7 of the soaps (two have extra coconut oil as they contain salt) except for colourants and essential oils. As I had nothing better to do in lockdown I decided to make some small batches (3 soaps each) of the worst offenders - lemongrass and poppy seed coloured with calendula, sandalwood (commercial) and bentonite clay coloured with cocoa powder (this one still develops ash on the top after unmoulding even when CPOPed) and mint and tea tree coloured with green tea wax. Without CPOPing these all develop ash also on the bottom corners and edges which bleach and crumble. That at least CPOPing has cured completely.

usual recipe CPOPed:

Olive Oil 300gm (50%)
Coconut Oil 210gm (35%)
Castor Oil 30gm (5%)
Shea Butter 30gm (5%)
Cocoa Butter 30gm (5%)

using a 2:1 water/lye ratio, roughly 5% superfat and a teaspoon roughly (6gm) sugar.

So I changed this recipe upping the olive oil to 55% and eliminating the castor oil and bunging it in the fridge as I used to do before the ash problem made me resort to CPOPing. First two soaps, the worst offenders, lemongrass and poppy seed and sandalwood and clay have not ashed at all! Oh and the colour of the lemongrass soap - lovely! The tea tree and mint have the faintest dusting which only the truly obsessed (eg me) would probably notice. The first one has been curing since 8th April, the second since 24th April and the last 30th April, so enough time I think to ash if they were going to.

So what is going on!!!???!!! Before I spend the rest of my life making tiny batches of identical soaps with and without castor oil, has anyone else noticed this? It would be fantastic (for me if not the rest of the soaping world) if castor oil was causing the ashing, but I don't quite believe it. But then I have never been able to understand why out of 7 identical base recipes and methods only 3 or 4 of the soaps ash and the same every time. It would make more sense if particular essential oils or additives were the cause but I have never been able to pin it down to one thing. This ash thing has taken most of the enjoyment out of soap making. I never had the problem until certifying this recipe, which didn't ash of course while under development, and always used to refrigerate (though many of my early soaps were goat milk).

Okay, so soda ash is sodium carbonate. Ash happens when the unsaponified lye reacts with the carbon dioxide in the air to form ash. The chemistry is NaOH + CO2 = Na2CO3. There are a couple of things you can do to help prevent it. One is to pour at a medium trace (not thin), there is less unreacted lye in a medium trace than there is in a thin trace. You can try spraying with rubbing alcohol - the idea is that when the alcohol covers the soap completely - the lye will not be able to react with the carbon dioxide. This never works for me. Another way is to completely cover your mold - plastic wrap - until it has completely saponified. This may take 2 or even 3 days.

 

[mtinetti61]

I've been curious about this ever since you mentioned it on another thread. What do you think is the difference between your house and garage that makes this happen? Is the garage damper, drier, warmer, cooler?

OK-- I'm going to throw out another variable here from my own experience. I am wondering whether something about climate could be a factor. I've been soaping for over 20 years. For the first 5 years or so I lived in northern Minnesota and had problems with soda ash no matter what formula I used. Since I have moved to southern MN I rarely have ash, with the same formulas. I do now spritz with 99% alcohol. And if I do get small amounts of soda ash I can wipe it right off with gauze and a little alcohol.

 

[linne1gi]

OK-- I'm going to throw out another variable here from my own experience. I am wondering whether something about climate could be a factor. I've been soaping for over 20 years. For the first 5 years or so I lived in northern Minnesota and had problems with soda ash no matter what formula I used. Since I have moved to southern MN I rarely have ash, with the same formulas. I do now spritz with 99% alcohol. And if I do get small amounts of soda ash I can wipe it right off with gauze and a little alcohol.

There are many variables. But soda ash is still a chemical reaction.

 

[JuliaNegusuk]

I do cover with cling film. But I seem to find that the ash forms days or even weeks after unmoulding. Looking at the lemongrass and poppyseed soap I cpoped a couple of months ago, it seemed fine when I unmoulded it and for ages afterwards. It now has ash on it. I don't know when it formed because I haven't checked it for a while. But that means it formed after the soap had saponified or at least done most of its saponification. The sandalwood and clay is similar. The lavender is all pockmarked and the ash has formed in the dips. They all seem to have ashed in the air pockets under the cling film but not till a lot later. It's not that much but it still doesn't look very nice. That presumably means that the ones I have just made over the last month may still ash. This is going to be a long term project. I think this batch for some reason is the worst I have ever made.

 

[linne1gi]

I do cover with cling film. But I seem to find that the ash forms days or even weeks after unmoulding. Looking at the lemongrass and poppyseed soap I cpoped a couple of months ago, it seemed fine when I unmoulded it and for ages afterwards. It now has ash on it. I don't know when it formed because I haven't checked it for a while. But that means it formed after the soap had saponified or at least done most of its saponification. The sandalwood and clay is similar. The lavender is all pockmarked and the ash has formed in the dips. They all seem to have ashed in the air pockets under the cling film but not till a lot later. It's not that much but it still doesn't look very nice. That presumably means that the ones I have just made over the last month may still ash. This is going to be a long term project. I think this batch for some reason is the worst I have ever made.

The thing is, as the soap cures, it loses water. We all know this. As the soap crystallizes, the water is being pushed out of the soap, any teensy tiny bit of lye gets pushed out as well. That’s the reason a water discount helps, less water to evaporate.

 

[Mobjack Bay]

The thing is, as the soap cures, it loses water. We all know this. As the soap crystallizes, the water is being pushed out of the soap, any teensy tiny bit of lye gets pushed out as well. That’s the reason a water discount helps, less water to evaporate.

@linne1gi - I've wondered if that might be why some additives, esp. clay, could make the ash worse. For example, if I add water to the clay to hydrate it, could a relatively slower release of water from the clay vs. the surrounding soap slow down the rate of water loss from the soap and increase the chance of ash developing as the soap dries?

 

[linne1gi]

@linne1gi - I've wondered if that might be why some additives, esp. clay, could make the ash worse. For example, if I add water to the clay to hydrate it, could a relatively slower release of water from the clay vs. the surrounding soap slow down the rate of water loss from the soap and increase the chance of ash developing as the soap dries?

I think if you add water to hydrate the clay, you do run the risk of more ash, simply because you have more liquid in the soap. If you don’t hydrate the clay, the clay tends to suck up the moisture in the soap, and the soap could be prone to dryness, chalkiness. It’s a balance. You will have to see how to make it work for you.

 

[Mobjack Bay]

I think if you add water to hydrate the clay, you do run the risk of more ash, simply because you have more liquid in the soap. If you don’t hydrate the clay, the clay tends to suck up the moisture in the soap, and the soap could be prone to dryness, chalkiness. It’s a balance. You will have to see how to make it work for you.

It happens even if I adjust the total water for the water I use to hydrate the clay. I tend to use relatively high lye concentrations, like 35%, and not all that much clay. I have never had chalky soaps, but I have had some very ashy clay soaps.

 

[penelopejane]

Wow. Really good video. From that low water and thicker trace seem to potentially be the answers. I don't usually worry too much about trace, as I think someone has mentioned. I will give it more attention. But cavity moulds are a bit trickier to fill with thick trace. But not impossible do I'll see how I get on. Really recommend video, very useful, very clear, thanks.

You don't need to use thick trace. Just medium. It works fine.
I don't think 80*F is warm enough be considered CPOPing to ensure gelling or avoid ash.
I use 110*F and that is considered low.
Do you use a thermometer to get your temps? For me that is important.
You didn't describe your CPOP method. When I used the oven I turned it off when I put my soap in and didn't open it again for 12-18 hours. I also put my soap in a box and wrapped it. If you are just covering it in cling film and putting it in the oven you are not getting the CPOP effect.

33% lye concentration using Soapcalc will avoid ash. You don't need to go higher.

I don't know why your refrigerated soaps don't get ash but the methods Irish Lass and others here describe are tried and tested methods that combined will stop the ash. I find consistently getting medium trace with varying recipes takes a lot of concentration.

 

[penelopejane]

OK-- I'm going to throw out another variable here from my own experience. I am wondering whether something about climate could be a factor. I've been soaping for over 20 years. For the first 5 years or so I lived in northern Minnesota and had problems with soda ash no matter what formula I used. Since I have moved to southern MN I rarely have ash, with the same formulas. I do now spritz with 99% alcohol. And if I do get small amounts of soda ash I can wipe it right off with gauze and a little alcohol.

Yes, environment makes a difference but also the micro environment of your soaping room.
Someone on the forum never got ash and someone who lived in the same street used the same recipe (and I think the same process) and got soda ash.
Everything in soaping is so variable and it is sometimes difficult to come to terms with the fact that tiny variations in processes can make a huge difference in the final soap. Then again some people manage to add a bit of lye water to oil and never measure temps and consistently turn out perfect soap. I am one of the former!!!

 

[JuliaNegusuk]

Penelope Jane, refrigerated soaps do get ash. That is my problem. The 3 or 4 that recently haven't are an anomaly. I always used to refrigerate fine until this certified recipe. I want to refrigerate, it's my preferred method. It worked without fail until I certified this recipe. It's like the soap knows I want to sell it and doesn't want to go so ashes. But some don't mind or want a new adventure so they don't ash! To me this explanation seems as likely as anything else!

I always used to use goat milk in my soaps. Maybe that's why my earlier soaps never ashed. The problem recipe was designed for a charity with a farm with meat goats. I didn't use goat milk in the recipe to avoid the inevitable questions "ooh is this your own goat milk? No, we eat them!". Didn't come across as a good sales pitch to me!

Since I've been making this recipe for the charity I haven't been making other soap, partly because I'm fed up of it. So I don"t know if my other recipes, with or without goat milk would ash or not. The one I made the other day that was a completely different recipe but no goat milk still shows no sign of ash. But I'm not convinced the recipe is the problem, why would it be?

Today I'm going to make a microbatch of lemongrass and poppy seed at 1.5:1 lye ratio refrigerate it and see what happens. But. I think I'll have to make a batch a week for a month or so to account for environmental factors eg today is bikini weather in UK, tomorrow will be UGG boot weather, which also might affect the outcome. I will report back my findings. Thanks for everybodys' help and interest. It's clearly an issue that exercises a lot of minds.

 

[penelopejane]

Penelope Jane, refrigerated soaps do get ash. That is my problem. The 3 or 4 that recently haven't are an anomaly. I always used to refrigerate fine until this certified recipe. I want to refrigerate, it's my preferred method. It worked without fail until I certified this recipe. It's like the soap knows I want to sell it and doesn't want to go so ashes. But some don't mind or want a new adventure so they don't ash! To me this explanation seems as likely as anything else!

I always used to use goat milk in my soaps. Maybe that's why my earlier soaps never ashed. The problem recipe was designed for a charity with a farm with meat goats. I didn't use goat milk in the recipe to avoid the inevitable questions "ooh is this your own goat milk? No, we eat them!". Didn't come across as a good sales pitch to me!

Since I've been making this recipe for the charity I haven't been making other soap, partly because I'm fed up of it. So I don"t know if my other recipes, with or without goat milk would ash or not. The one I made the other day that was a completely different recipe but no goat milk still shows no sign of ash. But I'm not convinced the recipe is the problem, why would it be?

Today I'm going to make a microbatch of lemongrass and poppy seed at 1.5:1 lye ratio refrigerate it and see what happens. But. I think I'll have to make a batch a week for a month or so to account for environmental factors eg today is bikini weather in UK, tomorrow will be UGG boot weather, which also might affect the outcome. I will report back my findings. Thanks for everybodys' help and interest. It's clearly an issue that exercises a lot of minds.

Don't forget to take really good notes including your trace levels. If you are only doing a batch a month you will forget what you did from one batch to the next.

 

[Susie]

I almost inevitably get soda ash. I have used all the different recommendations, to no avail. I just wash the loaf off before cutting, or if it decides to wait to show up on bars, I just wash them under running water and let them dry 24 hours before shrink wrapping. Much easier than fretting about things I can't control.

 

[lucycat]

When I first started soaping I had terrible ash. I was covering my mold and putting a blanket around it; really making a big deal of keeping the soap warm for 24 hours. I think I was forcing the soap too stay hot for too long a time. When I started working with goatmilk soaps I had to change to keep the soap from overheating and cracking. My ash problem decreased. If you don't have soda ash on the test soaps you need to think about the steps you took making the soap and what was different in the way you worked with the small batch compared to the regular batch size. It may not be the castor but the technique you used both with temps, how quickly it heated up, how quickly it cooled, how you covered the mold, etc. I think the idea of how trace might affect ash might be worth considering because it may affect the length of time the soap is in gel stage.

 

[TheGecko]

I've been curious about this ever since you mentioned it on another thread. What do you think is the difference between your house and garage that makes this happen? Is the garage damper, drier, warmer, cooler?

Carbon dioxide. We spend very little time in the garage. On the other hand, there are three adults and two cats in the house breathing out carbon dioxide on a fairly regular basis.

 

[linne1gi]

Carbon dioxide. We spend very little time in the garage. On the other hand, there are three adults and two cats in the house breathing out carbon dioxide on a fairly regular basis.

Carbon dioxide is just a component of our air - even outside there is plenty of carbon dioxide. You are thinking just of exhaled air and of the car emissions (which is actually carbon monoxide), but truly carbon dioxide is everywhere - just not in the concentrations that will harm you.

 

[Megs NZ]

I haven't completely read the whole of this thread but have you considered adding a small amount of beeswax to your recipe? I add 2% for hardness and to counter act soda ash, cp soap at a rather warm temp, ensure I force gel phase in my one kg moulds, wrap with cling wrap and cover with my towels. Next day un-moulding and cutting is fine.

 

[JuliaNegusuk]

I will add beeswax to my list of things to try it water discounting fails. Thanks Megs.

I made my first batch of 1.5:1 lye ratio soap yesterday. Only 2 soaps. This much water is a tiny amount. I wasn't sure if my calendula petals would provide enough colour in that little water, but it seems to have worked. I only want a pale yellow anyway and this came out well. Regarding level of trace it sort of blobbed into the mould and needed to be encouraged into the corners with a spatula. It was probably stiff enough to maintain much of it's shape if I hadn't smoothed it out so a fairly thick trace I would have thought. I then refrigerated the mould overnight covering one of the cells with cling film and leaving the other open. The first I will keep in the mould for 3 days, the other I unmoulded today. I'll make another batch of this soap next week. I'm running out of lemongrass oil so I might then switch to my lavender soap. I'll need to rethink that one as it has silk in it. That level of water discount probably won't dissolve the silk so I'll maybe try 1.8:1 or something and use less silk, I use too much anyway. The lavender soap doesn't ash as much anyway and hopefully won't go all pockmarked in the fridge, which is another reason I don't like cpoping.

I will let you know how I get on.