I know, it is odd! I was not expecting this at all, and have kept that particular soap near at hand to watch for a change.
Here is an update on this:
Knowing, as I do, that medications can alter the sense of taste and the sense of smell, I decided to look at that more closely, even though I had not noticed any other smell sensations changing.
What I found was that some BP meds, including the one I am currently taking, have been known to alter the sense of taste and smell. I have not noticed any changes to my sense of taste, and since they are so closely linked (taste & smell), it had not occurred to me to consider one of my meds as a suspect. I had not thought of that until recently because, I had only ever noticed it when significant and thankfully temporary. (St John's Wort produced the most noticeable taste alteration I have ever experienced along with a changed sense of smell.)
Now this really does paint a different picture as related to how to interpret my soaping FOs in the future! I don't know how I feel about this now. I certainly don't intend to put soapmaking above my health, so I guess I'll just have to adjust somehow, and live with it. But does this now mean all FOs and EOs are going to smell differently to me than they did before I took BP meds? I have only noticed it with DB, though and only with that one batch, although I have not used DB with VS since, so cannot be sure it would or will not happen again.
So another factor that occurred to me, but now seems to be less likely to be a causal factor, is that with that batch of soap, I used the bottom-of-the bottle of DB FO, and maybe there was a different concentration of ingredients at the bottom of the bottle or some residue? I don't and can't really know as that was not something I would look for when making soap. But, as I said, this has never happened before for me with DB, and it wasn't the first time I had used up the last of a bottle. But it was the first time I had mixed BCN VS with DB, so that's how I came up with my interpretation.
Now I can't be sure. I'll keep an eye (or a nose) on it.
Really? That's so weird. I use BCN VS in every batch of soap I make, and Mad Oils DB is the only DB I use and I've never gotten a Root Beer scent.
It's always smelled the same in the soap as it has OOB, possibly just a little less subtle.
As for VS changing the scent of my soaps, it does sometimes, but by the time a full cure is achieved, the weird chemically smell induced by the VS is gone (usually got by the time I cut it, but some scents are stubborn! LOL)