Mayday! Mayday! DOS????

[MGM]

Hi all! Many photos to really document what's going on here. I only have partial information about these guys.....they were made in January, 6 bars as part of a high/low water experiment, and were creamy white, as you can see in the photo right after they were made.
I did 3 bars of each (uncoloured/unscented) and found very few differences between them, and soon mixed them up and forgot all about them. I did label them and their label says: Coconut, lard, olive, grapeseed, castor oils; lye. But I can't find my soapcal sheet for them, so I don't know the proportions. I don't have a single soap that has those 5 oils, so I'm guessing that I ran out of olive and topped it up with grapeseed (just to tell you there likely wasn't much grapeseed, but more than 5%).

They were packed away with a number of other soaps about 8 weeks ago and when I pulled them out yesterday, I found that they were splotchily discoloured, felt a bit greasy, and had a bit of a smell. It's not unpleasant, but I don't think they used to smell like that.

Any ideas?? Does DOS present as a general discoloration, in addition to orange spots? Guess I need to go look at the other soaps they were sitting with, since DOS is catchy :-(

 

[Megan]

It's DOS. The whole bar can go rancid at once.

 

[MGM]

Waaah any idea of why? I've made dozens of batches and haven't ever seen anything.

And it's not to do with the high or low water, since it's 4 bars (hoo boy, I wonder who has the other 2....or maybe the other 2 are fine, because it was the conditions here that were a problem.)

 

[Megan]

I would say probably a combination of things. Maybe the grapeseed, depending on your superfat. Perhaps the storage conditions. It could even be some type of accidental contamination when making. When I first started I'd sometimes fret when I'd make a soap and I realized that my stick blender still had water stuck in the shaft from washing it, that then gets into the soap...who knows if that could cause DOS or not, but I don't think its out of the realm of possibilities. It also looks like one is far more rancid than the others...maybe that would be the high water bar? If it weren't fully cured when packing (depending on the water content), then that could have gone rancid first and passed it on to the others.

 

[cmzaha]

Depending on your percentage of lard that could be part of the culprit but I am guessing it is the lard combination with the grapeseed. I never go over 27% lard for this reason, as I always have problems with lard even with my additives as counter measures. Sorry it is frustrating, and yes, the entire bar can go off at once.

 

[MGM]

So interesting! As I was scrolling through my soap calc sheets looking for this one, I realised that, despite my self-perception, I really do have LOT of different recipes, however, I don't think I have any with lard + grapeseed. But I have 100+ bars with 15% grapeseed and dozens of 100% lard ones...
Woe is me, how to know?
FWIW, these are the first unscented/uncoloured bars I've ever done...maybe THAT was it --normally I cover up the DOS

 

[Megan]

See, I don't know much about lard because I avoid animal fats in my soap, but I would think if you could lower the superfat to 0-1 that you might not have to worry about DOS as much. Adding a chelator and an antioxidant may help as well.

In fact, I'm doing an experiment at the moment with some RBO that was just nearing it's end of life. I made a 0% SF 100% RBO bar and I'm waiting for it to cure for a year. I think it's been about 3 months now, and it is still perfect...just soft-ish, as you would expect 100% RBO to be. Edit: 3 months and 1 day to be exact...I find it funny that I got that right off the top of my head.

 

[cmzaha]

See, I don't know much about lard because I avoid animal fats in my soap, but I would think if you could lower the superfat to 0-1 that you might not have to worry about DOS as much. Adding a chelator and an antioxidant may help as well.

In fact, I'm doing an experiment at the moment with some RBO that was just nearing it's end of life. I made a 0% SF 100% RBO bar and I'm waiting for it to cure for a year. I think it's been about 3 months now, and it is still perfect...just soft-ish, as you would expect 100% RBO to be. Edit: 3 months and 1 day to be exact...I find it funny that I got that right off the top of my head.

Lowering superfat does not always work. I soap at 2% sometimes lower and anything over 27% lard will go dossy for me. I add in Tetrasodium EDTA and Sodium Gluconate at 0.5% each and extra BHT, my lard already contains antioxidants. There just is not much I have not tried.

 

[MGM]

@cmzaha Have you done 100% lard bars? I'm wondering if there's a sour spot (opposite of a sweet spot) where up to this much is ok and over this much is ok but in the middle.....

Well, sounds like it could be purt near anything....contamination of some sort is not out of the question, I suppose. This is my only recipe with lard + grapeseed, although that seems rather random 'cause I've got lard + everything else and grapeseed + everything else. The high water *could* be an issue, except, IIRC, the "high" water was 2.7:1, which is the ratio I used for my entire first year of soaping, and all those soaps are still fine.

Not being able to figure it out is gonna haunt me! I will walk around worrying about all soaps suddenly turning on me now!

 

[cmzaha]

Ask Obsidian about some of my 100% lard trials, which I tried with several different brands of lard. This is how I managed to settle on the 45/27% tallow/lard which I love.

 

[MGM]

Ask Obsidian about some of my 100% lard trials, which I tried with several different brands of lard. This is how I managed to settle on the 45/27% tallow/lard which I love.

Sounds like a whole thing! I wish I could get some tallow...guess I could always go to the butcher across the street and see if they have any and learn to render.....

 

[Todd Ziegler]

Lowering superfat does not always work. I soap at 2% sometimes lower and anything over 27% lard will go dossy for me. I add in Tetrasodium EDTA and Sodium Gluconate at 0.5% each and extra BHT, my lard already contains antioxidants. There just is not much I have not tried.

Thanks for this response. I've not had this problem before but your preventative measures for lard is very helpful. Does the EDTA or sodium gluconate cause any acceleration problems?

 

[Susie]

I go up to 65% lard with no issues. I have, however, had olive oil go rancid in the bars on me, as well as the one time I used grape seed oil. I now refuse to buy any oil with less than a year left before it expires.

 

[shunt2011]

I use lard at 45% with no issues. I too used grape seed oil once and got DOS bit that was years ago. Never used it again.

 

[MGM]

All right I did a bit of sleuthing....

I've identified 20 batches of soap, dating back to April 2019, where I used GSO, usually at 10-15%, but once at 20%. Three batches are just a couple of weeks old, so I wouldn't expect anything on them. Another 5 batches are from late May, which is still probably too early. Much of my soap is still packed away so I couldn't check them all, but I saw about half of them and none of them had DOS.

I am on my 2nd jug of GSO and I don't know if these were made with the tail end of the old jug or the beginning of the new jug. If it's the end of the old jug, I have some soap that was made just before it which is fine. If it's the beginning of the new jug, all that soap is fine, too. I guess the problem is, there's nothing else in my collection with DOS (I hope!). And, I guess that's not a huge problem, but inquiring minds want to know what's going on!

ETA: current jug's best before date is Sept 2021, and has been open since Jan? Feb? March?

thanks for all the help, everyone.

 

[cmzaha]

Thanks for this response. I've not had this problem before but your preventative measures for lard is very helpful. Does the EDTA or sodium gluconate cause any acceleration problems?

No, I do not get any acceleration from either additive. It is odd that I do have problems with lard and assume it is the brand available here. When I first started soaping I would get Snowcap lard from Walmart and did not have problems with it, but it became unavailable in our local store, when it came back in it was too pricey.