Is this DOS?

[merrysoap]

Hello, I've been soaping for about a year and just experienced what I think may be DOS. This bar was made on 4/9/24 with the following recipe:

21oz Olive oil (purchased from Sam's Club)
10.5oz coconut oil (Bulk apothecary)
1oz castor oil (Bulk apothecary)
2 tsp sodium lactate
1.8oz lilac fragrance oil (Brambleberry)
TD and ultramarine violet oxide colorants

I did CPOP, preheated the oven to 170 and turned heat off before putting the mold in (after spritzing with 91% isopropyl alcohol). Kept the oven light on for 3 hours, then turned it off and let the soap stay in the oven overnight. Unmolded and cut the next day.

I keep my curing bars in the basement with a fan going since it's the coolest/least humid area in the house. Was turning my bars today and noticed a single small spot (2-3mm diameter max) on two out of ten bars... all the others look fine. Is this DOS like I suspect? If so, what do you think caused it with this recipe and what can I do to avoid it in the future? Would you toss these bars or let them keep curing and see what happens?

Hello, I've been soaping for about a year and just experienced what I think may be DOS. This bar was made on 4/9/24 with the following recipe:

21oz Olive oil (purchased from Sam's Club)
10.5oz coconut oil (Bulk apothecary)
1oz castor oil (Bulk apothecary)
2 tsp sodium lactate
1.8oz lilac fragrance oil (Brambleberry)
TD and ultramarine violet oxide colorants

I did CPOP, preheated the oven to 170 and turned heat off before putting the mold in (after spritzing with 91% isopropyl alcohol). Kept the oven light on for 3 hours, then turned it off and let the soap stay in the oven overnight. Unmolded and cut the next day.

I keep my curing bars in the basement with a fan going since it's the coolest/least humid area in the house. Was turning my bars today and noticed a single small spot (2-3mm diameter max) on two out of ten bars... all the others look fine. Is this DOS like I suspect? If so, what do you think caused it with this recipe and what can I do to avoid it in the future? Would you toss these bars or let them keep curing and see what happens?

Forgot some other recipe info:

Lye 4.64oz
Distilled water 10.05oz (3% discount)

These bars are curing in the same area that my other bars are curing and as far as I can tell, I haven't seen similar spots on other bars yet.

 

[Mobjack Bay]

The spot on the second bar, lower left quadrant, looks like DOS to me. The spot on the first bar likely so as well, but it also looks like there is some sort of inclusion in the soap.

As for a cause and what to do to prevent DOS, this article is very helpful.

 

[merrysoap]

The spot on the second bar, lower left quadrant, looks like DOS to me. The spot on the first bar likely so as well, but it also looks like there is some sort of inclusion in the soap.

As for a cause and what to do to prevent DOS, this article is very helpful.

Thank you so much! I've been down the rabbit hole this week and think I found the culprit... I was gifted a bottle of what turned out to be very old castor oil and used it without knowing how old it was.

The article was very helpful. I was able to mostly eliminate some of the common causes and hope that it was the old oil that was the issue. So far, none of the batches I made before or after that oil was used up have had any issues with DOS. *Knock wood.* Let's hope it stays that way!

 

[Ekuzo]

Yup, old oils may cause DOS. Just curious, did you notice anything strange about the smell, the look or the consistency of that particular castor oil?

Edit: I just noticed the last comment is 3 months old, please delete mine if needed

 

[ScentimentallyYours]

I found the culprit... I was gifted a bottle of what turned out to be very old castor oil and used it without knowing how old it was.

Good catch on the castor, @merrysoap. Last month I had to toss the remainder of a gallon of castor because it had turned rancid. I’ve been religious about monitoring my other oils for rancidity, but it hadn’t occurred to me before to check the castor oil. The rancid odor was unmistakable. Duh! Will purchase smaller bottles of castor from now on.