Soda ash through soap

[Jess_]

Hello,
I am new to soap making, have been making small batches (300-600g oils) of soap for only two months now. So far my worst experience with soda ash has been small patches on the top of a couple loafs; which I’ve simply cut off.
This morning I unmoulded and cut a loaf that I’d made 36 hours before. It was a recipe I’ve successfully used before, with 5% super fat & 34% lye concentration, all ran through SoapCalc. The top had a thick coat of soda ash, which I thought “no big deal, I’ll just trim the top off”. But as I started to cut I saw the soda ash had made its way through the whole soap.
I’ve heard/read that soda ash is mainly an appearance issue and the soap is still safe to use. Is this true? What should I do with this batch?

Also any advice on avoiding this on the future? I always spray with isopropyl alcohol once the batter is in the mould and again 10 mins later. Any advice is greatly appreciated, thank you!

 

[IrishLass]

Welcome, Jess! Yes- it is true that ash is just an aesthetic issue. As long as it does not zap, ashy soap is perfectly safe to use.

One of the best ways I've found to avoid ash is by using less water in the batch, and also encouraging the soap to go through the gel stage. I do both of those things and very rarely get ash, and in those rare times that I do, it's such a light sprinkling that it washes right off with wet cloth. No need to trim it off. For what it's worth, the amount of water I use in my batches is 1 part lye to 2 parts water (a 33% lye concentration).

Spraying the top of my soap with alcohol has never worked very well for me...it was always hit or miss.

The worse case of ash I ever got was in a soap I purposely prevented from going through the gel stage by putting it in the fridge. The ash was so thick that there seemed no end to it as I was trimming it off one of the bars. Thankfully, I decided to just leave the rest of the bars alone because I'd have had just slivers of soap left by the time I was done trimming! lol Instead, I just left the rest of the bars alone on my curing rack to cure and it made perfectly good soap to use, albeit a bit unslightly to look at.


IrishLass

 

[penelopejane]

There are lots of ways to encourage gel one way is to soap warm and put your soap mold in a cardboard or polystyrene box and cover it with a blanket and leave undisturbed for 18-24 hour.

Can you wash the white off? If not, it might not be soda ash. If you can’t wash it off let us know what your recipe is and your soap temps and we will try and help solve it.

 

[Jess_]

Welcome, Jess! Yes- it is true that ash is just an aesthetic issue. As long as it does not zap, ashy soap is perfectly safe to use.

One of the best ways I've found to avoid ash is by using less water in the batch, and also encouraging the soap to go through the gel stage. I do both of those things and very rarely get ash, and in those rare times that I do, it's such a light sprinkling that it washes right off with wet cloth. No need to trim it off. For what it's worth, the amount of water I use in my batches is 1 part lye to 2 parts water (a 33% lye concentration).

Spraying the top of my soap with alcohol has never worked very well for me...it was always hit or miss.

The worse case of ash I ever got was in a soap I purposely prevented from going through the gel stage by putting it in the fridge. The ash was so thick that there seemed no end to it as I was trimming it off one of the bars. Thankfully, I decided to just leave the rest of the bars alone because I'd have had just slivers of soap left by the time I was done trimming! lol Instead, I just left the rest of the bars alone on my curing rack to cure and it made perfectly good soap to use, albeit a bit unslightly to look at.


IrishLass

Thank you very much for your reply. Do you find that using less water still gives you plenty of time to work with the batter? The water to lye ratio I was given on SoapCalc was 1.94:1. But because I was aiming for the swirl I added a touch extra water. Perhaps next batch I will need to be more precise with the water?

There are lots of ways to encourage gel one way is to soap warm and put your soap mold in a cardboard or polystyrene box and cover it with a blanket and leave undisturbed for 18-24 hour.

Can you wash the white off? If not, it might not be soda ash. If you can’t wash it off let us know what your recipe is and your soap temps and we will try and help solve it.

Thank you very much for your reply.
This soap was covered with cardboard and a thick blanket for about 36 hours hours prior to unmoulding. I did however have a layer of cling wrap on the soap to prevent extra moisture, but when I checked after the 36hrs it had trapped in condensation. Do you think this could be the issue?
I did as you suggested and tried to wash the soda ash off and the soap did not change at all.
The recipe I used was:
35% Olive Oil
30% Coconut Oil
20% Palm Oil
5% Avocado Oil
5% Castor Oil
5% Jojoba Oil
I had a 5% super fat and 34% lye concentration. The lye water was around 113°F when I added it to my oil mix which was around 108°F.
No fragrance oil, only ‘pigment’ colourants add. The last time I used the colour I had a problem with the darker blue, but it was only a thin layer of ash on top.

 

[KiwiMoose]

Soda ash aside - it's a beautiful swirl, and I love the colours.

 

[Cellador]

I get the deep soda ash inside my soaps sometimes. Usually when I pour at a very thin trace and then do a swirl on the top. I've never been able to determine the exact cause, but I wonder if I am introducing tiny amounts of air into the soap, causing deeper ash. ? I usually just try to wait a little longer before pouring if I think the trace is too light.

 

[Jess_]

I get the deep soda ash inside my soaps sometimes. Usually when I pour at a very thin trace and then do a swirl on the top. I've never been able to determine the exact cause, but I wonder if I am introducing tiny amounts of air into the soap, causing deeper ash. ? I usually just try to wait a little longer before pouring if I think the trace is too light.

I think you might be on to something with pouring at thin trace. The batches I’ve made and accidentally stick blended too much and ended up frantically scraping into a mould have turned out with no soda ash. Where the batches I’ve had at thinner trace to try more advanced swirls, have been the ones to give me trouble.

 

[Susan M]

I read a super tip on a soaper's blog - I don't remember who it was, unfortunately. After the cure and cut, pour a little isopropyl alcohol in a bowl and gently scrub the ashy parts with a soft toothbrush. It really works!

 

[penelopejane]

I read a super tip on a soaper's blog - I don't remember who it was, unfortunately. After the cure and cut, pour a little isopropyl alcohol in a bowl and gently scrub the ashy parts with a soft toothbrush. It really works!

You don't have to scrub with a toothbrush. Just spray the alcohol on really lightly.

If your soda ash is just on the outside of a mold or individual molds the cause can sometime be that the mold wasn't really, really clean. You can either use a bit of NaOH to really clean the mold and wash it off or spray a little alcohol on them and let it dry.

Don't use too much alcohol as that has been known to cause a weird DOS like brown on the surfaces where the alcohol was used.

 

[Jess_]

Update: after two weeks there has been no change in appearance to the soap I originally posted about. Will test this week and see if it causes irritation.
I haven’t made any soap since that batch until today. I was extra careful to make sure I poured at a thicker trace, but a little over 6 hours later and I can see it has patches of soda ash on top, doesn’t look too serious but will see in about 30 hours when I unmould and cut the soap.
Interesting side note: I left a small amount of the soap batter in my bowl and after it got quite thick I scraped it into a pile and left it on the spatula, on the table completely uncovered and absolutely no soda ash has appeared.
Going to regroup and make a batch tomorrow, this time I’ll ditch the alcohol & cling wrap and simply cover with a piece of cardboard and see what happens.