What's causing this?? Cold process, Essential oils discoloration

[Steph Hoskins]

Hi! I've been making this formula for ages and it's my best seller but the last 3 batches have been really strange - waaay more susceptible to soda ash (which I don't mind that much) and cracking, and a weird dark discoloration at the edges/corners... I haven't changed suppliers, or method as far as I'm aware! I did wonder if the fact it's warming up a bit here (not exactly tropical though, I'm in the UK) but fridged it for 12 hours after moulding last batch and it didn't make any difference... I'm wondering if it's connected to the essential oils which are lemongrass and rosemary?? Using 25g/kg of each;Pic attached. Any suggestions gratefully received!

 

[dixiedragon]

I have a theory that humidity makes soda ash worse. I have a soaping buddy who lives about 30 minutes from me. We both use tap water (same water source) and lard. But I have very little ash and she has some (sometimes a lot, depending). Only consistent difference? I have a dehumidifier in the room where I cure.

 

[Steph Hoskins]

Hmm that would totally make sense - you don't get more humid than the UK at the moment!! Thanks, I might try the theory as we do have a dehumidifier... Any thoughts on discolouration and crumblyness in eggs ledges and ends?

I should add the pH is fine, btw...

 

[earlene]

Getting rid of 2 of those pics is possible in edit, but when they are attachments, it takes a bit of trial & error sometimes. I have had that happen, too. When you go to edit, scroll to the very bottom of your post where it lists attacments. Delete two of them. Then save. If it doesn't work the first time, it might take another time to fix it. I had a hard time with that myself a couple of time.

Now back to your real question.

That must be really disturbing for you when nothing has changed as far as you know. Is there any chance your EO is old? Or perhaps a brand new bottle? If you suspect the EO, have you tried making the same recipe without one or the other EO to test out your theory? (A small batch, of course, just for testing purposes?)

My lemongrass does slighly discolor, but it uniform across the entire bar, and there is no cracking. I don't know what is causing that. Have you considered your lye (caustic)? Does it crumble at all?

Is it only the one bar doing it, or do all bars from the same batch do that? And if only one, then end bar?

 

[Steph Hoskins]

Edges not eggs ledges!!

Thanks Earlene yes it's a tad crumbly at the ends and edges but I'm pretty sure that's the sofa ash as it's not throughout the bar just the ends and edges which I can cut off but I'm losing a whole bars worth and there's still the discoloration.... As I said lye/pH is fine so just the aesthetics of it but yes it is bloody annoying!! I'll try to upload a diff pic

See? They're not horrific just... Rustic!! I would love to work out what's causing it - I wasn't even getting soda ash three months ago!

 

[Obsidian]

Is the partial gel new now that its warming up? Sometimes when I get partial gel the ends/edges get darker like that.

I'm not seeing ash, I'm seeing stearic spots from the soap heating and cooling at different rates

Maybe pop it in the freezer after pouring, see if that helps, or try to encourage full gel.

I'd be curious to try a unscented batch, see if it behaves better.

 

[Steph Hoskins]

Ok just a quickie - how long can I put it on the freezer for?? Without it adversely affecting it.... Thanks!

 

[Obsidian]

I've done overnight, then into the fridge for a day to thaw. Once its back at room temp, it can be cut.
This can cause the soap to stay a bit softer since saponification is slowed. Don't be surprised if that happens.

 

[Steph Hoskins]

Actually that one did go in the freezer for a bit then fridge for 12 hours after, might be air bubbles you're seeing I have a bit of a rustic method! I sell my bars as really simple - minimal ingredients, all natural/Organic and 'authentic' finish (I just stamp and wrap them) so not too worried about the soda ash it's the different colour at the edges and corners.... It might be the essential oil but not sure how that would cause it only at the edges..??

Got a batch in the freezer now with no eo so will update!

Meanwhile Antoine have any experience of eo discoloration pleat let me know!

 

[cmzaha]

I am with Obsidian, I also see stearic specks, but that is immaterial. If I were you I would go with a full gel and forget the freezer. I do see a partial gel and I find with some soaps that get a partial get will discolor around the edges or get a very thick ash. Not sure why that happens but I assume it is something to do with how it all heats up. I have had soaps with lard and partial gel go pinkish around the edges and /or get such heavy ash the edges will crumble.

 

[earlene]

Good call, Carolyn. I was so distracted by the yellow around the edges, I didn't notice the partial gel. But it is definitely visible in the last photo.