# Single EO scent (fading) test



## szaza (Mar 12, 2020)

I had a bunch of (new) EO's that I wanted to test and thought I'd update on it here in case someone else is interested. I used a salt bar recipe because it needs a long cure so I have ample time to sniff all the soaps repeatedly before using the soap. I just hope the salt doesn't interfere with the scent. Anyone experience with that? 

These are the scents I used: 
Amyris at 5%
Bergamot at 5%
Eucalyptus at 5% 
Peppermint at 5% 
Petitgrain at 5% 
Rosemary at 5% 
Peru balsam at 4% 
Star anise at 1%
Ho wood at 0.4-0.7%*
Elemi at 0.4-0.7%*
These are the maximum amounts for CP soap. Ho-wood and Elemi were difficult to measure and I probably added a bit too much.. 
I made this soap on February 1st and I just packaged all the soaps after a bit over 5 (almost 6) weeks of cure time. The scent has already changed in many of the soaps. 

Here's a short summary of perceived fading after cure (5-6 weeks)
Scent got stronger: Amyris (but still subtle)

Stayed+- same: Petitgrain, Rosemary, Peppermint, Peru Balsam (Ho Wood)

Scent changed: Elemi, Star Anise

Faded noticably: Eucalyptus

Faded too much: Bergamot


Here's a longer write-up:
*Amyris* smelled wonderful OOB, slightly sweet and a bit fresh/floral. 
After unmolding I could hardly smell it anymore and I was disappointed, but somehow the scent came back after +-4 weeks of curing and is now a soft kind of floral scent, not very strong but pleasant.
*Bergamot* is just lovely OOB, very fresh, typical bergamot (earl grey) scent and it smelled the same right after unmolding. After cure there's a freshness left in the soap, but the typical bergamot smell has gone.
*Eucalyptus* probably doesn't need a scent description. It's still typical eucalyptus after cure, but already quite a bit softer than right after unmolding.
*Peppermint* is lovely sweet and minty (like the candy) and is still strong after cure.
*Petitgrain* I absolutely hated OOB and wasn't my favorite after unmolding, but it has mellowed out and transformed into a lovely green (maybe slightly floral?) smell.
*Rosemary* smells just like the herb. It probably mellowed a bit during cure, but still smells lovely and distinctly like rosemary.
*Peru balsam* smells sweet and herbal OOB although mainly the vanilla like sweetness remains in the soap (with a hint of herbal in the background). It did discolor my soap a chocolaty brown and it was difficult to measure due to the sirup like thickness of the substance. It's still wonderfully sweet smelling after cure.
*Star anise* smells just like the spice OOB plus a bit of a medicinal smell that a lot of EO's seem to have. It was a wonderful anise smell after unmolding (without the medicinal smell it had OOB) but mellowed out to be mainly sweet with a hint of anise after cure. I think this will be a good one for blends, but I probably won't use it much on it's own (also because of the low maximum usage rate)
*Ho wood* has a lovely spicy-woodsy scent OOB, but is very soft in soap because of the low maximum usage rate. I still smell it, but it's faint which is a shame with such a wonderful smell. I'm not sure if it has lessened during cure since it was a soft smell to start with. 
*Elemi* gives me a headache OOB and I didn't care for it much after unmolding. It's a green, herbal, maybe slightly spicy scent. After cure however, it mellowed out and became a wonderful fresh green scent that I think will work wonderful in blends (and I actually like it on its own). 

Of course scent is very subjective, so I probably others will perceive these smells differently.


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## szaza (Mar 12, 2020)

Maybe I should add that I also did another test on Monday (March 9th) with a different recipe, comparing sweet orange 7 fold to blood orange at 5% (blood orange is sweeter and discolors quite a bit more than sweet orange 7x)  I'm mainly curious as to how fast they fade and if there's a difference.
I also did cade at +-1%, which discolored to a nice caramel color and smells quite strong even for such a low usage rate (I think it's allowed at a higher percentage, but I know it's strong, so felt I'd probably never use it at more than 1%)
Lastly I'm comparing lavandin (my worst fader up to now) at 50% lye concentration and 33% lye concentration (1:1 and 2:1 water:lye). To see if water content influences fading. I can't say much about any of these yet as they still need to cure.

Edited to add a picture of discoloration from EO's.
Back row are left Peru Balsam (4%, in a salt bar) and right cade 1% in a high oleic white recipe.
Front row are left blood orange 5% and right sweet orange 7fold at 5% both with the same very white recipe as cade. (Orange7x barely discolored)


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## Arimara (Mar 12, 2020)

Sounds interesting. Some scents trigger my headaches so I've never thought to experiment like this.


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## SoapSisters (Mar 12, 2020)

Thank you!! This is SO helpful and interesting! I purchased Ho Wood a while ago and couldn't find the usage rate, so thanks for that as well. I'm looking forward to your updates.


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## szaza (Mar 12, 2020)

I use eocalc.com for calculating safe usage rates, though if you really want to be correct you need to find out the specific amounts of all possible irritants in your specific EO from the supplier (because it can change from batch to batch) and calculate safe usage rates according to ifra standards, though that's quite a lot of work. Here's a link to how to do that if you're interested. 

These soaps also don't have enough cure time to really give definitive answers on scent fading, so I'll try to update regularly (and hope I don't forget)


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## HowieRoll (Mar 13, 2020)

I _really_ appreciate your efforts, szaza, as well as your taking the time to share the results!


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## szaza (Mar 13, 2020)

HowieRoll said:


> I _really_ appreciate your efforts, szaza, as well as your taking the time to share the results!


Haha thanks, now let's hope I remember to update..  writing it down here is a good way for me to not neglect checking up on them and taking notes .


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## cmzaha (Mar 13, 2020)

szaza said:


> I had a bunch of (new) EO's that I wanted to test and thought I'd update on it here in case someone else is interested. I used a salt bar recipe because it needs a long cure so I have ample time to sniff all the soaps repeatedly before using the soap. I just hope the salt doesn't interfere with the scent. Anyone experience with that?
> 
> These are the scents I used:
> Amyris at 5%
> ...


The experiment is great but I feel your choice of using a salt bar for testing is not a good choice. I have made salt bars since I started soaping and find very few scents hold well in salt bars even when I do an extra heavy load of fragrance. The salt just seems to eat the fragrance whether EO or FO.


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## szaza (Mar 13, 2020)

Thanks for letting me know! I was wondering whether the salt would have an effect.. Too bad for the experiment. At least if a scent sticks in these conditions it'll stick in regular soap for sure (Trying to look on the bright side)


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## cmzaha (Mar 14, 2020)

szaza said:


> Thanks for letting me know! I was wondering whether the salt would have an effect.. Too bad for the experiment. At least if a scent sticks in these conditions it'll stick in regular soap for sure (Trying to look on the bright side)


That could be very true. I always thought Spearmint would stick using it at 7.5% ppo since my Speamint is very strong and nope it did not stick. This was in some confetti salt bars where I had only 75% salt. Salty Air, Salty Mariner, etc, DB, Nag Champa I do fine will stick at 7-8% ppo, in 100% salt bars.


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## szaza (Mar 14, 2020)

I'm curious if any of the EO's will make it through.. I'm not counting on it, so I hope I won't be too disappointed I was planning on documenting when exactly the soaps stop smelling like the EO, so I was already prepared to end up using unscented salt bars. It's just going to be harder to wait the whole 6months-1 year cure time if the EO's fade completely before that 
Do you have an idea of how much faster scents fade in salt bars? Just to have a general idea of what to expect in a regular recipe.


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## KiwiMoose (Mar 31, 2020)

Thanks for posting this @szaza - very interesting and useful.


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## szaza (May 3, 2020)

After the 6 week update in March the single EO soaps were wrapped in parchment paper and stored in a plastic ice cream box to prevent airflow.
Today at +-3 months I unwrapped, sniffed and re-wrapped, so I'll write down what I thought of each scent.

Bergamot: subtle, but distinct green scent. Not very citrussy, but hasn't faded either.
Amyris: soft, sweet, subtle, but somehow also dark/complex scent.
Eucalyptus: very distinct and fresh eucalyptus smell, really opened up my sinusses. (Guess the storage conditions helped with this one, seeing how it faded in the initial 6 weeks cure)
Peru balsam: I had one bar packaged and one bar left in open air. The packaged one had more green/herbal notes, while the one left in open air had more sweet, slightly notes (I guess a bit spicy/woodsy as well?)
Rosemary: typical rosemary smell, though quite a bit more subtle than I remembered from last time.
Peppermint: strong minty smell
Ho-wood: nice fresh, subtle scent (low usage rate). I don't think it changed much in the last 6 weeks (but memory can be unreliable)
Elemi: nice fresh, clean scent, also subtle (low usage rate)
Petitgrain: strong, distinct green scent
Star anise: sweet, spicy, typically anise, though a bit subtle due to the low usage rate.

ETA: 
I also wanted to update on the soaps I made on March 9th: blood orange vs orange 7-fold and lavandin in 33% vs 50% lye concentration. 
Initially the blood orange had a clear discoloration, but somewhere between 4-6 weeks that discoloration disappeared completely along with most of the scent. The scent of orange 7-fold has faded quite a bit as well, but seems ever so slightly more apparent than blood orange at this point. The color fading kind of took me by surprise. I did a test with blood orange in September 2018 (more than 1.5 years ago) and I still have a bar that's more orange on the bottom than the top (the eo's weren't mixed in very well.. you can read about it here.)
In the lavandin soaps I think I'm starting to pick up a difference between high/low water, where the low water seems to smell a bit stronger. This difference is bigger than blood orange vs orange 7x, but not big enough to make any definitive statement. 
There's also a soap with cade at 1%, which still has its discoloration and smoky aroma.


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## HowieRoll (May 6, 2020)

Thanks so much for the update and work put into this!


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## szaza (Sep 3, 2020)

Completely forgot to update on these. It's been about 7 months since I made these soaps, so time to get out the coffee and smell some soap.

Amyris is subtle, but Amyris has been subtle to my nose since the beginning. It might have gotten a bit more subtle though. Not really sure.

Bergamot was still surprisingly bergamotty. I expected this one to have faded almost completely by now, but it's still fresh, citrussy and distinctively bergamot. I'm doing a little happy dance while smelling and typing 

Eucalyptus still smells fresh and clean, though less intense then bergamot. I think it faded a little.

Peppermint is still peppermint. Not much to say about that.

Petitgrain is also still very distinct. 

Rosemary is very similar to what I remember/expect. It's not as intense as peppermint and petitgrain, so it might have faded a bit (more). At the same time, pm and pg are pretty intense smells and I'm not sure rosemary was as intense as those 2 after pouring either. 

Peru Balsam is sweet and vanilla-ish with a hint of herbal. Might be a bit less intense than I remember, though still clearly present.

Star Anise still has a bit of scent left, but it's very faint and not very anise-y anymore.

Ho-wood is a fresh, subtle green scent. Not sure if it faded. I think I remember it being rather subtle from the beginning.

Elemi is subtle and green. Again not sure if it faded.

I think overall there probably has been some general light fading, though more so in anise and less so in bergamot (or at least less than expected).


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## atiz (Sep 3, 2020)

This is so helpful, thank you!

Bergamot is probably my favorite scent, but have never tried it in a soap on its own. But all this is very encouraging, so I will!


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## soapmaker (Sep 3, 2020)

I am so surprised about star anise.  In my blends I have to be careful because star anise overpowers everything and lasts for over a year.


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## penelopejane (Sep 3, 2020)

By storing the soap in a plastic container you are extending the life of the scent. If you sell soap it won’t be stored in a plastic container. Might be a good idea, if you do it again with a regular recipe, to have a control soap for each scent that is stored on a shelf rather than in a plastic container.


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## soapmaker (Sep 3, 2020)

penelopejane said:


> By storing the soap in a plastic container you are extending the life of the scent. If you sell soap it won’t be stored in a plastic container. Might be a good idea, if you do it again with a regular recipe, to have a control soap for each scent that is stored on a shelf rather than in a plastic container.


Of course that's why I store in a plastic container and keep only 5 on the shelf so it is fresh for the customer.  They will use it,  not store on a shelf for 7 months.


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## szaza (Sep 4, 2020)

@penelopejane I don't sell and don't really have the intention to do so either, so I'm mainly interested in what works for me personally.

@soapmaker I used star anise at a very low percentage, because according to eocalc it has a low usage rate. (1/5 of most of the other scents). That might be the explanation.


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## penelopejane (Sep 4, 2020)

soapmaker said:


> Of course that's why I store in a plastic container and keep only 5 on the shelf so it is fresh for the customer.  They will use it,  not store on a shelf for 7 months.


The problem I have with my recipes being high olive oil is that the longer they air dry (not in plastic containers) the harder they get. So I want to cure them for ages but that just doesn’t work for EOs.   I’ve also seen/smelt lots of soap in shops which have no scent left at all.

You’ve worked out a system which works for EOs and your recipe which is great.


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## Dawni (Oct 26, 2020)

Thank you @szaza! Your experiments are always helpful.

I love elemi! Could be just my nose (and maybe my patriotic brain lol) but it blends with with _almost_ everything I've tried it with, even black pepper lol (with others of course). It's a mainstay in a balm I make, too. 

You've given me a couple of new ideas to try too.. Maybe buy myself Amyris and Petitgrain


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## SeaSuds (Oct 26, 2020)

Thank you this is very helpful❤


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## szaza (Oct 26, 2020)

Dawni said:


> Thank you @szaza! Your experiments are always helpful.
> 
> I love elemi! Could be just my nose (and maybe my patriotic brain lol) but it blends with with _almost_ everything I've tried it with, even black pepper lol (with others of course). It's a mainstay in a balm I make, too.
> 
> You've given me a couple of new ideas to try too.. Maybe buy myself Amyris and Petitgrain



Elemi is a scent that has really grown on me!


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## szaza (Jan 26, 2021)

Almost one year after making these, I thought this would be a good time for a final update. They have mostly been sitting in a closed plastic container, while individually packaged in parchment paper.

Here are my smelling notes:
*Amyris*: A fresher/more herbal/less floral and also slightly softer scent than I remember (I wonder if some of the other scents have carried over), but still a nice scent and definitely amyris.
*Bergamot*: Still a light, fresh and citrussy scent, though the typical 'bergamot' (earl grey) scent has faded significantly.
*Eucalyptus*: Still fresh and uplifting eucalyptus, probably faded a bit (hard to remember, since I haven't smelled these in about 5 months).
*Peppermint*: Very fresh, very much still peppermint. Strongest one yet
*Petitgrain*: Not as strong as the peppermint, but still very clearly a green petitgrain scent.
*Rosemary*: Still distinct, though probably faded a bit as well.
Peru Balsam: still a sweet, vanilla like smell, with a slight herbal undertone.
*Star Anise*: soft and sweet
*Ho-wood*: a bit harder to detect, still there, but very subtle
*Elemi*: soft and fresh.

So to recap, I was able to kind of divide the scents into 4 strength categories:
*Weak, but detectable*: Amyris, Bergamot, Ho-wood
*Softer, but clear scents:* Elemi, Eucalyptus, Star Anise
*Distinct, but not overpowering*: Petitgrain, Rosemary, Peru Balsam
*Still going strong*: Peppermint.

Keep in mind, these are 1 year old and I don't think any of them are as strong as when they were first made. I'm comparing them to each other, not to freshly made soap.

I think keeping the soaps away from air has really helped retain the scent. I've been doing that with most of my soaps now and it does seem to help prevent scent fading with most EO's during storage. Now the problem I'm running into is that some soaps seem to lose their scent while they're in use, which is a bit disappointing.

On a different note, I'm coming back to the idea that beeswax might influence scent longevity. My soaps are reacting very differnt in my new home (even soaps with a longevity number of 30 become slimy), which made me turn to some beeswax soaps I made last year. One of them had sweet orange eo at 70% of the total EO and the orange was still very clearly present at +-11 months and did not fade while in use. The other one was 1year 4months and had a spicy/floral scent that is still as vibrant as I remember when I unmolded, even after a few weeks of sitting in the shower.


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## Mobjack Bay (Jan 26, 2021)

I am soooo happy for this thread popping up again.  Now I have it bookmarked!  Thank you for circling back around with the updates and the idea about the beeswax.  What percentage of beeswax are you using?  Are you adding the EOs after the batter reaches emulsion?


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## szaza (Jan 26, 2021)

Mobjack Bay said:


> What percentage of beeswax are you using? Are you adding the EOs after the batter reaches emulsion?


I'm using 3-5% and added the EO's after HP cook - probably should've mentioned these were HP soaps..


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## szaza (Apr 8, 2021)

Since the last update, I've started using these soaps at the bathroom sink. 
*Amyris* smelled quite nicely and distinctly when washing with it. I was quite surprised! 
*Bergamot* was barely detectable, I only smelled it when I held the soap up to my nose (which I tend not to do when washing my hands)
*Eucalyptus* was faint, but noticable. 
I'm now using *star anise* and I clearly smell it while washing my hands. 

I'll update more after I've tried more of them at the sink.


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