Quantcast

DOS question

SoapMakingForum

Help Support SoapMakingForum:

houseofwool

Well-Known Member
Joined
Jan 18, 2013
Messages
1,159
Reaction score
706
I know this has been addressed a dozen times, but I'm still questioning some things.

Liz's recent post got me thinking and I went back and looked at some of my bars from 6-9 months ago and some have started to go rancid and I don't really know why.

Basic recipe is (roughly, but not exactly)

25% CO
35% OO
25% Palm
10% Shea
5% Castor
(some may have had SAO)

Typically superfatted between 5-8% and using either water or goats milk as the water. There were a lot of variations, but they were all roughly equal parts CO, OO, PO and the Castor and Shea stay the same.

We have pretty good water around here and I have always used tap, not distilled.

My question is if dissolved minerals could be causing this (doesn't seem likely).

The oils have been purchased from most of the big online places, Brambleberry & Soapers Choice for the most part. Lye is from Essential Depot.

There are a variety of EO's and colorants that were used. and the DOS does not seem to be consistent. Batches from the same time frame, some developed DOS and some are great.

I am stumped as to what is happening and I would really like to get it figured out.

Any thoughts?
 

DeeAnna

Well-Known Member
Joined
Feb 20, 2013
Messages
12,815
Reaction score
17,789
Location
Northeast Iowa, USA
Okay, so you're going to get a bazillion opinions about this. Here's my take on DOS. As always, YMMV.

I don't pretend to have the answers to DOS, but here are some trends I am seeing when others talk about DOS in their soaps and when I work with my own soaps. First off, there is overall DOS and there are isolated spots of DOS. I think you have to look at these as somewhat separate issues.


Overall DOS -- Yellow/orange discoloration over most of the bar, sometimes many measles-like spots and sometimes an overall color change. Sometimes the soap becomes soft, warped, and smelly and can weep liquid from the darkest areas. Often affects most or all of an entire soap batch.

The main issues IMO are the ingredients, the recipe, and the method of storage.

Possible causes -- Old, oxidized oils; oils with a short shelf life (corn, hemp, etc.); overly high superfat (yes, I know about Kevin Dunn's experiments, but I think his experimental design absolutely does not support some of his conclusions about superfat vs. DOS); exposure to excessive light and/or humidity in storage; oxidized or old FO or EO (oxidized lavender EO seems to be a particular culprit); and metal contamination in the air or storage containers or in the water, lye, or other recipe additives (chlorophyll, for example).

Solutions might include using fresh oils from a reliable supplier; storing oils in a cool, dark place; careful selection of other recipe ingredients; moderate superfat; storing soap in low light and low humidity conditions; and storing soap in a container or on shelving that is clean and chemically inert.


Isolated spots of DOS -- One or a few yellow/orange dots on a bar. Typically does not affect an entire soap batch.

This appears to be caused by a localized problem, such as a bit of contamination from one's hands or excessive exposure to light.

Solutions might include the use of packaging that prevents customers from directly handling the soap, handling soap with clean hands, storing soap on non-metal surfaces, and rotating soap in a store display to keep it as fresh as possible.


PS: You asked if dissolved minerals in your water could be an issue. There are many who use tap water to make soap with no apparent problems. But I do know that iron contamination can trigger DOS and iron can come from old pipes and some types of well water. I play it safe and use distilled water, but others scoff. <shrug> Again, YMMV.
 
Last edited:

houseofwool

Well-Known Member
Joined
Jan 18, 2013
Messages
1,159
Reaction score
706
It seems to be both spotty AND overall DOS. there is definitely the funk of rancid oils.

Everything has been stored in the same general conditions. The soaps cure on plastic coated wire shelving, in my finished basement. I hung a curtain to cover the window, to prevent color fading.

The bulk oils are either stored in the basement, in the same room, or are in the kitchen where I actually soap.

The part that strikes me as so strange is that one batch is fine and the next has DOS, but was made from the same bulk oils using the same technique.
 

kazmi

Well-Known Member
Joined
Apr 9, 2013
Messages
1,381
Reaction score
417
Location
MI
The part that strikes me as so strange is that one batch is fine and the next has DOS, but was made from the same bulk oils using the same technique.
Exactly the same - same FO, same colorant, same additive, same storage method?

Have you made a batch that you experienced DOS and an exactly identical batch later that didn't get DOS. How quickly do you see it appearing? As frustrating as it may be you may need to do some experimenting making small batches (using one ingredient at a time if necessary to narrow it down) following an exact protocol each time to find the culprit.

I'm with DeeAnna as far as tap versus distilled water but I know many use it with no issues. I just don't trust my city water. And I agree with her statement about Kevin's superfat results. The superfat in your recipe doesn't seem to be too high but it may be high enough if you have a bad ingredient.
 

houseofwool

Well-Known Member
Joined
Jan 18, 2013
Messages
1,159
Reaction score
706
I will have to go back and check additives, but, I have two that used orange EO that I had to trash because they smelled rancid. EOs and colorants vary from batch to batch.

No fragrance oils at all. Colorants are either clays, oxides or herbal.
 
Top