curing and ash question

I have made 8 batches of soap, and 6 of them have (what I think) is ash.

Five of those didn't develop ash until about 3 weeks into their curing time; is that typical? If so, does that mean there's something wrong with my recipes?

Also, one soap (the only one colored with dyes, scented with peppermint eo) became a little grainy after several weeks of curing....any idea why?

Someone taught me to spray alcohol on top and it prevents the ash. It had happened to me and since spraying, no problems at all. HP or CP it works

Thanks - I'll remember that. I'm not really worried about preventing ash, since the soap is just for my use.

The majority of the ash I've found shows up mostly on the cut sides, and it shows up weeks later. From the pictures I remember seeing on SMF, ash shows up on tops of soaps before they're even cut. This makes me wonder if what I have really is ash or something else.

I would like to know the answer too. Half of all of my soap developed ash.

I usually see more ash on the tops of my bars right after the saponification process, but it can happen anywhere on the bar during the cure period. Ash might take some time to develop depending on the humidity in the air and the amount of water in your recipe. Ash can look unsightly, but all-in-all it's a good thing, since your soap is becoming even milder as lye reacts with the carbon dioxide in the air to form soda ash.

In an ongoing thread about an unusual castile soap recipe, we're finding out that excess lye slowly becomes neutralized during the cure time. Ash is one result of that process. http://www.soapmakingforum.com/showthread.php?t=42922

Graininess may result from the crystallization process that soap goes through during the cure period. I'm not a super expert on this -- just doing some reading about it at the moment -- so I can't offer much more information than this. There may be other, better reasons for the graininess of your particular soap, including inadequate mixing of your colorant before it's added to the soap batter. Maybe others will chime in with better ideas.

DeeAnna, the way you phrased that made me think of a question. If ash results from the lye neutralizing, does that mean that if a soap forms ash that it was perhaps a teeny tiny bit lye heavy? Like not even enough to fail a zap test? I read most of the other thread you mentioned and remember someone (probably you) saying how excess lye travels outward as the water left the soap and reacts with the carbon dioxide in the air to form the soda ash.

In the case of the unusual castile recipe, yes, there is excess lye to neutralize and it appears that the excess water in this soap moves at least some of the excess lye to the surface where it is neutralized with CO2. Ash formation is proof that this is happening. I was doing some thinking and calculations this morning, and I'm not sure just the formation of soda ash is the whole story. If ash formation is the only thing that is neutralizing the excess lye, the soap should be covered in mounds of soda ash. No one who has made this recipe, including me, is finding this to be the case. Not having a chem lab to study this, I'm not sure exactly what else is going on, but despite my ignorance of the reasons, it's clear the soap is becoming considerably less lye heavy as time goes on. AnnaMarie's experience shows the soap eventually becomes mild and skin safe, given time.

In the case of a properly-made soap that is lye neutral or superfatted, it's a little different. Taken as a whole, no, the soap cannot not be lye heavy. That said, there can be localized areas of higher alkalinity within the soap, especially when the soap is young. For example, the bottom of a soap can have higher alkalinity than the top, based on experiments by Kevin Dunn (see his book Scientific Soapmaking) and from information I've gleaned from threads in this forum. I suppose a person could think of that as being a teeny bit lye heavy, although the chemist in me has problems with that -- I just view this localized lye-heaviness as a chemical reaction that is still in process rather than an end result.

Also, soap has a crystalline structure that gradually develops during cure. The crystal structure, being formed of soap molecules, is chemically neutral, but the spaces between the crystals are filled with a water-based liquid that is alkaline. Some of the alkalinity in this liquid is a natural consequence of soap being soap, and some could be excess alkalinity that will continue to react and neutralize during cure. The development of the crystalline structure, the entrapment of liquid within this structure, and ongoing but slow chemical reactions are also part of the increased mildness of soap during cure -- cure is not just about evaporating water.

I think a big part of what I'm learning from the lye-heavy castile and from my recent reading about the chemistry of soap is this -- The cure time is every bit as important as the initial saponification. My "normal" soaps are teaching me this too, but the effect is much more subtle than the lye-heavy castile, so it's easier to overlook or downplay.

I wish I had a better answer for you, but this is the best I can offer.

So if I read that correctly it may possibly be caused by higher concentrations of lye in areas?

i've stopped trying to find out what causes soda ash. when the ash fairy decides to stop by, i just embrace her...

Yep it could be.

Something weird seems to be going on with the multi quote function on the app..

Seven: thank for the laughter lol. The ash fairy visited my first batch but apparently didn't like my other two.

DeeAnna: thank you for the info!