DOS + Goat milk soap questions

[narnia]

I am wondering....does DOS happen only in CP soaps or HP soaps, too?

I read that in order to avoid DOS in CP, to use distilled water, fresh oils, and to keep the SF to 5% or less.

What about with goat milk soaps? Will the oils in the GM go rancid? or the minerals in the GM cause issues with DOS?

Can I avoid DOS in GMS by using HP? Is there something about HP that prevents DOS?

Would CPOP revent DOS?

Thanks in advance for your help!

 

[Arimara]

^^ Goat's milk soaps are not going to go rancid unless you added the goats milk into the soap during rebatching, which would be a fool thing to do.

Preventing DOS goes a little bit further than what the advice you picked up gives. You have to really know your oils to prevent it. Some oils are more prone to rancidity than others. These oils include grapeseed, canola and safflower oils. The same is not necessarily true of these oils if they are labled as 'high oleic', which can last a great deal longer. Others have pointed out that there is a connection to an oil's linoleic and linolenic fatty acid levels and DOS. Oils high in content of these fatty acids tend to be the same ones guilty of causing DOS in many a soaps.

Really, limiting the amounts of the naughty oils in question to about 20% may help (am I being nice?) in conjunction to your advice. I'm sure I could have been a little more thorough but at the moment, I'm not feeling it (I hurt my knee again after having a nasty fall last week).

 

[traderbren]

I hope someone will correct me if I'm wrong (who am I kidding? Someone will absolutely correct me if I'm wrong...), but your technique or processing choice will not affect DOS as much as your choice of oils. Some are more prone to DOS, and even then it's a bit of a crap shoot, which is why it's important to keep some bars back for a year should you ever choose to sell. Friends and family are far more forgiving than paying customers.

 

[LoveOscar]

I have 2 milk bars (used with grocery store full fat cows milk :shock that I super fatted at 8% that I am waiting to cure. I'm waiting for DOS too, but I used high olive oil recipes, so I'm doubting it will happen. Always an experiment haha.

 

[narnia]

I have 2 milk bars (used with grocery store full fat cows milk :shock that I super fatted at 8% that I am waiting to cure. I'm waiting for DOS too, but I used high olive oil recipes, so I'm doubting it will happen. Always an experiment haha.

So, does olive oil reduce chances of DOS?

 

[LoveOscar]

I've not been soaping for very long, but I haven't heard or known of olive oil soaps to go bad. Pure castille bars are 100% olive oil, and I've never heard of those puppies going rancid, and they're left to cure for years sometimes.

 

[Arimara]

When in doubt, you can rely on The Soap Queen for soapy answers!

This may be helpful too. As always, experience is the best teacher.

 

[galaxyMLP]

GM soap shouldn't get DOS any more often than any well formulated recipe. HP will definitely not decrease your chances of getting DOS. In fact, it may even increase them. The high heat that you put HP soap through (sometimes for extended cook times) can make the rancidity process go faster. I don't have any experiment data on this but if you accidentally left your soap in the cooker too long and it got super hot you might artificially increase the likely hood of DOS.

However, if you do HP right, it should be just the same amount of chance to develop DOS in HP or CP.

 

[narnia]

GM soap shouldn't get DOS any more often than any well formulated recipe. HP will definitely not decrease your chances of getting DOS. In fact, it may even increase them. The high heat that you put HP soap through (sometimes for extended cook times) can make the rancidity process go faster. I don't have any experiment data on this but if you accidentally left your soap in the cooker too long and it got super hot you might artificially increase the likely hood of DOS.

However, if you do HP right, it should be just the same amount of chance to develop DOS in HP or CP.

I thought that cooking might destroy the rawness of the oils so as to keep them from going rancid. As in nuts that are raw can go rancid faster than roasted ones.

 

[galaxyMLP]

There are 2 major pathways that rancidity occurs: Bacterial and physical chemical breakdown (heat, metals, time, moisture, ect.).

I've never heard of raw vs. roasted nuts going rancid faster but, I don't really know much about nuts. This would be my explanation:

What I would guess is that in raw nuts you have bacteria and moisture present. That bacteria and moisture over time makes rancidity more likely than in a roasted nut where its heated. When you roast the nut you kill off the bacteria and you remove most of the moisture. When you remove the moisture, it makes it much harder for the bacteria to come back. Plain chemical rancidity is a slower process than bacterial although, they have the same end result (that the oils break down in to stinkier compounds like ketones and aldehydes). That means in the case of the nuts, removing bacteria/moisture= longer shelf life. It would make sense to say that since you're heating the nuts to do that, that heat is what extends shelf life. In soap, though, that is not the case.

In soap, we use lye in HP and CP soap making. Lye kills the bacteria off, right from the start; you've eliminated the faster breakdown pathway. Properly made soap also won't re-grow that bacteria. That leaves the heat from HP soap to be the main difference. Heat causes oils to go rancid faster because the oils are more likely to break down. You have more energy going into the system and that causes things to break down faster.

Is it going to be an appreciable difference in a properly formulated recipe? No, probably not. But, I definitely would not say that HP'ing soaps would decrease the chance of rancidity.

 

[dixiedragon]

I hope someone will correct me if I'm wrong (who am I kidding? Someone will absolutely correct me if I'm wrong...), but your technique or processing choice will not affect DOS as much as your choice of oils. Some are more prone to DOS, and even then it's a bit of a crap shoot, which is why it's important to keep some bars back for a year should you ever choose to sell. Friends and family are far more forgiving than paying customers.

WRONG! (j/j) :mrgreen: In my experience, curing in a damp, cool place can lead to DOS. I had a batch where some bars ended up in the attic (dry and hot) and some bars ended up in the basement (cool and damp) and the attic bars were fine and the basement bars had DOS. Same batch, everything the same.

 

[shunt2011]

I agree that where you cure them and how can also affect the final product as to DOS etc.

 

[galaxyMLP]

Hot and humid is also a no-no. I had some bars up on the second story and my AC went out. No DOS before that AC went out and within 2 days, 3 bars had spots (this was an experimental 70% canola batch that I expected to DOS). It happened to be almost 100% humidity outside and the those got up to 98* F upstairs. That kind of heat + humidity was soooo not good. That being said, none of my other, well formulated bars came down with DOS!

 

[paillo]

I still have some goat milk bars 3-4 years old that are great, no DOS. I used OO, CO, palm, PKO, avocado and castor. Sodium lactate, 50/50 split method goat milk/distilled water, adding powdered goat milk as well. Way before I developed better recipes, and years before I discovered the wonders of brine soap. Cured on bakers' racks.

And some early soaps did develop DOS when I was curing in a closed cupboard.

 

[narnia]

How long does it take for DOS under normal indoor conditions? I guess the darker bars would not show any orange spots, would they?

And what is "brine soap?" Is it the same as salt bars?

 

[shunt2011]

How long does it take for DOS under normal indoor conditions? I guess the darker bars would not show any orange spots, would they?

And what is "brine soap?" Is it the same as salt bars?

There's no way to determine when a soap will get DOS or even if it will. I've been fortunate and have only had it occur once. It was actually one of the Shampoo bars that I had stored in the bathroom instead of in my storage room and it got all kinds of DOS. Otherwise, never get it. (thank goodnes.)

 

[Muskette]

I haven't heard or known of olive oil soaps to go bad. Pure castille bars are 100% olive oil, and I've never heard of those puppies going rancid, and they're left to cure for years sometimes.

The only DOS I've ever had were on a batch of 100% olive oil castile bars. My husband accidentally left the window open overnight in my curing room, and the next morning there were dew drops all over my soaps. I dried them off, but that entire batch eventually developed DOS. So I don't think olive oil is immune, and I do think high humidity during cure is a huge contributing factor.

 

[IrishLass]

How long does it take for DOS under normal indoor conditions?

From all my reading about the subject on the different forums, there seems to be a somewhat unified consensus that DOS usually doesn't rear it's ugly head until at least 3 to 4 weeks have gone by (at the earliest). Oftentimes, if spots appear on a soap before that, it usually ends up being leaking FO or something else that wasn't mixed in well.

As an aside, in Dr. Kevin Dunn's experiments with DOS, he had to manipulate the curing atmosphere in order to make the soap for his experiments DOS much faster than they normally would. Although he doesn't come right out and state specifically what a "normal" first time appearance for DOS is, he relates a typical scenario in his book on page 279 of what the majority of us soapers have experienced with DOS- namely that it usually does not appear until about 4 weeks have gone by.

Oh- and in his experiments, Dr. Dunn was able to get his 100% OO sample soap to DOS. The soap that ended up resisting DOS in his experiments was his coconut oil sample.


IrishLass

 

[narnia]

AND...it sounds like humidity AFTER the cure is a huge factor as well.

Irish lass...Thanks for that info! Does Dr Dunn have a book with all this info?

 

[topofmurrayhill]

AND...it sounds like humidity AFTER the cure is a huge factor as well.

Irish lass...Thanks for that info! Does Dr Dunn have a book with all this info?

Scientific Soapmaking. You can get it on Amazon.