Does Hardness of soap increase the chance of EO/Glycerin seepage?

[Astro]

I have made several batches of soap now using 3 recipes. The first is a Bastille, 80% OO/13.33% CO/6.67% Castor, the 2nd is a Milk soap, 71% OO/26% CO/3% Castor, and the third is my hard bar of 60% CO and 40% Sunflower. They are a mixture of HP and CP with additives and without and all have been curing for at least 6 weeks. I live in an area that can be humid, can be dry and can also be damp and the cure has happened through all of these stages.

One batch of CP hard soap (60/40) has started to seep and I suspect there are a number of factors that could be contributing to it but not sure what is the most likely cause. I experimented with this batch (do you call it batch or bar or loaf?) as it is a cheap one to make. I tried marbling and added liquid food colouring (green and blue) - the green reacted with the lye making it purplish - and I also added cocoa powder for colour and Rosemary EO to this batch. I also made a batch of cucumber and mint with the same recipe and just a hint of peppermint.

The seepage looks golden like EO and tastes a bit like it too but rinses off with no oily residue. It also feels sticky like glycerin (Does glycerin taste sweet when it comes out of soap?). The colour of the seepage could be related to the colourings I put in, but I suspect it is both EO and Glycerin but I don't know what would cause this as this particular batch seemed fine to start with but after 6 and a half weeks it started with this.

Could it be dampness in the air bringing it out, could it be that as the soap cures and crystalizes it is pushing out the EO? Could my additives have something to do with it? The cucumber soap has a slight glazing but nothing like this batch? The first pic is of the batch just after making and the 2 bars are now. Unfortunately I wiped off the seepage.

Thank you all for all the information you have given me so far. This forum is great

 

[shunt2011]

What is a mixture of HP & CP? I've never heard of that process. They could be sweating, if its humid or damp. Could also be EO seeping out if not mixed in well enough. Did it just start or has it been happening since you took them out of the mold and cut them?

 

[Astro]

What is a mixture of HP & CP? I've never heard of that process.

Sorry, bad explanation on my part - what I meant was that I made several batches, some using HP and some Using CP. Not Both at the same time.

They could be sweating, if its humid or damp. Could also be EO seeping out if not mixed in well enough. Did it just start or has it been happening since you took them out of the mold and cut them?

it has just started in the last week, until then it was fine. I thought I had mixed in the EO thoroughly but this may be the issue.

I was wondering about what Deanna said in this post, about the crystalisation of soap molecules, and whether the fact that the soap is a hard soap would it push out the EOs
https://www.soapmakingforum.com/threads/cure-time.35831/#post-548993

 

[penelopejane]

I think it has to do with humidity in the air. Could also be additives like salt. Salt bars can take 6 months to stop sweating. If you haven’t got good ventilation you might need to use a dehumidifier. I change the cotton tea towel they sit on regularly.
A bar is a single bar of soap, a loaf is uncut. A batch is however much you mixed up together - could be more than one loaf.

 

[DeeAnna]

I don't think the physical hardness-like-a-rock has much to do with sweating. I've made some amazingly hard soap from tallow and from coconut oil and not noted they have a tendency to sweat easier. That's just a casual observation, however.

I doubt the crystals in a hard soap "squeeze" the liquids within the soap any more firmly than the crystals within a softer soap. An analogy -- You can build a toy cabin out of wooden Lincoln logs or you can use gingerbread to build a similar toy cabin. Do the hard wooden logs exert more pressure on the air inside the cabin compared with the softer gingerbread?



What I do know is humidity does make a difference. My soaps do sweat when the relative humidity is very high, but they never sweat when the humidity is moderate to low (like maybe around 60% RH and lower). The only exception is salt soap which sweats a lower RH than other soap does.

The "sweat" will not be just essential oils -- it's going to be a mixture of whatever chemicals happen to be in the liquid contained within the soap. That will be mostly glycerin with lesser amounts of water, dissolved soap, dissolved salts, fragrance, etc.

Another issue that can cause soap to sweat is rancidity. A soap bar that is "all over" rancid will often have an orange-y film of "sweat" on it too. It will also smell "off".