Does anchoring fading EO's work?

[szaza]

Warning: this is a very long, detailed post.. I felt I needed to be precise about my recipe and notes, but feel free to skip over those parts, you won't miss much The parts explaining the 'experiment' and 'goal' basically summarize everything.

About 5-6 months ago I was out of special soaping oils and most essential oils and basically everything else, so I had to make do with what I had left. I made 2 very simpel batches in a week's time; one was 100% CO, the other 92% OO, 5%castor, 3% beeswax. Both had the same EO blend (10% patchouli, 70% lavandin, 20% lemon).
Now, 5-6 months later, there seems to be a rather big difference in scent between the two. Most notably, the lemon scent lingers in the 92% OO version. In that soap, I added the EO blend to melted beeswax first, before adding in the soap batter at very light trace. In the 100% CO soap, I added the EO's at trace and that was it (this soap only has a very faint lavender smell to it by now).

This made me want to read up on anchoring and it seems there is not really any clarity and some experienced soapmakers said there was no way to effectively anchor a scent. I started doing HP in the hope to have EO's stick longer, but I'm actually not sure if it's really helping or not.

Me being curious and having some time off, decided to do a little experiment:
3 notoriously fading EO's (lemongrass, blood orange, lavandin) subjected to 4 different ways of adding to the soap batter:
1. Added at trace (1g/cavity)
2. Added with clay at trace (1g EO in 0,5g clay per cavity; 6g/400g = +- 2tsp clay ppo) no clay in other portion of soap
3. Added with melted beeswax at trace (1g EO in 1g beeswax per cavity)
4. Added after gel/cook.

I made up a simple ok-ish recipe that wouldn't use too much expensive oils and wouldn't go rancid too easily (and included beeswax)
3% beeswax (12g)
27% coconut oil (108g)
30% olive oil (120g)
30% rice bran oil (120g)
10% shea butter (40g)
Total oil weight: 400g
Superfat: 5% (55g NaOH + 5g with CA -> 60g NaOH total)
Lye concentration: 30% (128,4g distilled water)
Fragrance: 3% of oil weight (12g or 1g per cavity)
Citric acid at 2% of oils in distilled water before adding lye (8g CA + 5g extra NaOH)
12 cavity silicone cupcake mold

These were my notes on the process:
All oils except beeswax weighed together. Beeswax in 2 bowls: 3g and 9g.
Water and Citric acid weighed and dissolved.
Clay weighed and divided over molds (eyeballed division - should have weighed).
EO’s weighed and divided over 9/12 cavities. (mixed with clay in 3, unmixed in 6)
Cavity mold covered with silicone mat
Lye weighed and added to water, oils melted. Lye added to oils and handstirred until emulsion (beeswax accelerates)
3g beeswax melted and devided over 3 cavities with EO’s only; mixed.
Batter devided over these 3 cavities and mixed.
NOTE: EO’s should be mixed in hot bowl with beeswax, not beeswax added to cold molds -> beeswax solidified instantly. Beeswax and EO’s melted together with blowdryer and soap batter slowly added and mixed, added and mixed etc.. to prevent bits of solid beeswax.
9g beeswax melted and added to remaining batter (first added some batter to hot beeswax and mixed, then added to remaining batter)
Remaining batter devided over remaining molds (eyeballed amount of soap per cavity - probably better to weigh soap batter)
Put in preheated oven around 70-80C until all gelled.
Cool down a little bit and add EO’s to 3 cavities that were left unscented.

My goal is to smell the soaps different time intervals to try to see if there is any difference between adding the EO's at trace or trying to anchor in one way or another. Not sure if solid conclusions can be drawn in the end, because I eyeballed the amount of soap batter per cavity and since my recipe is rather small, variation is relatively large. The relative amount of EO might have an effect on staying power, so I'll have to somehow correct the results for bar size/weight if possible. Even if nothing comes out of the experiment, I hopefully just made some confetti-able soap after all the scent has faded

 

[shunt2011]

Interesting. I use lemongrass and lavandin and have never had an issue with them sticking. I have a couple bars that are 3-4 years old and still smell pretty darn good. I do CP though. Citrus scents are notorious for fading though.

 

[szaza]

Interesting. I use lemongrass and lavandin and have never had an issue with them sticking. I have a couple bars that are 3-4 years old and still smell pretty darn good. I do CP though. Citrus scents are notorious for fading though.

@shunt2011 that's great to hear you're having such good scent sticking with lemongrass and lavandin!
I never really dared to use single EO's in soap, because I heared so much about fading. I also always tried to add the oils after cook and/or anchor in one way or another. I haven't had scentless soap, but I've noticed after a year I just smell the base note (haven't made soap long enough to have 3-4 year old bars though).
For the experiment I looked in my cabinet and thought about which oils would fade the fastest. Blood orange was number one. I would've liked to try lemon as well, but didn't order it last time, so I went for lemongrass. To be honest, it's brand new and I haven't used it before, but read from some people that it faded on them. The lavandin faded quite a bit in the 100% CO soap and I have lots of the stuff, so that was number 3. Unfortunately I have very little info on that oil. My mom got a big (1liter) bottle of "lavender oil" from a friend who went on a holiday to the provence and she uses it to add to her cleaning products. The scent is lavender-ish but doesn't have the warm sweetness of the "real" lavender, which makes me suspect/assume it's a cheaper variety of lavandin oil (though I'm by no means an expert!). It could also be an FO in disguise since it's not very well specified on the bottle. Anyway, it fades, so I thought it's good enough for this experiment, but it might not completely represent other lavender-type oils.
Another thing I thought of in this experiment is that all the soap went through gel phase. It was easier for this experiment and I like my soaps to have gelled to get a more fibrant color (either HP or CPOP). There could of course be a difference wether you gell or not.. If I get some time today I might start a small ungelled batch, but I think I'll be running around like a headless chicken today (and all of next week) so probably going to stick with this for now

 

[shunt2011]

I gel all my soaps. I need them out of the mold as soon as I can. You’ll find what works for you though.

 

[szaza]

Just unmolde, turns out I didn't mix the EO's in the batter well enough, so no EO on top, lots of it on the bottom..

 

[shunt2011]

Yep, you need to be sure to get them mixed in well. It can also cause seeping if not mixed well enough.

 

[szaza]

Yeah... I think this experiment can officially be called a failure already. I thought I thoroughly mixed the EO and the batter, but apparently it wasn't good enough (probably has to do with small molds and adding the batter to the EO in stead of other way around). Sorry for wasting people's time, I should have waited to unmold before starting the thread. I was really happy about it yesterday, so I wanted to share, but it was a bit too soon. Anyway, confetti soap, here I come!

Also, I have no clue anymore why I thought lemongrass was a fading EO. I thought I read it somewhere, but when I tried to look it up again I only found articles about its staying power. Maybe I really messed up and mixed lemon and lemongrass?
I don't have many EO's since I'm a hobby soaper, so I tried to find the ones that were the most prone to fading.. Apparently I managed to avoid most of them

 

[Lucinda]

Well I sure would like to know how to anchor EO's!
The only ones that seem to perform well for me are lavender and peppermint.
I made some gorgeous soap with bits of lemon and orange peel, and scented it with orange, lemon and pink grapefruit EO's. It doesn't smell at all !
They're so expensive too.

Oh, and lemongrass seems to last really well...for me, anyway.

 

[Steve85569]

Citrus does fade for me. That's why I have a large bottle of lemongrass EO.
Seems to me that there are others that just refuse to come to mind right now...

 

[szaza]

I'm so frustrated with this thing I might have to try it again with a better setup
Some inprovements I'd like to make are:
- Individual molds for easier weighing (in stead of a 12 cavity mold)
- First put batter in the molds, then add EO's ands mix more thoroughly than last time.
- Choose EO's with more fading issues to test
- Add a 5th testing condition: ungelled soap.
Does anyone have something to add to the changes?

As I'm thinking about setup, I'd like your input on some things:

1. What kind of inexpensive/household items can be used as small (single use) individual molds? My boyfriend pointed out plastic cups are polypropylene and pretty chemically/thermal resistant, but I don't feel comfortable using them as I'm probably going to have to force gel in the oven. I have an oven thermometer, so I can control the heat pretty well and make sure it doesn't go over 80C, but the reaction heat might make the soap warmer than that. Darn why didn't I buy a soaping thermometer yet?

2. I'm going to have to use EO's from my cabinet as I'm not going to order anytime soon.
This is what I have: Blood Orange, Sweet orange 7X, Lemongrass, Litsea, Peppermint, Pine, Ylang Ylang, Patchouli.
I also have some small tester bottles of: Eucalyptus, Palmarosa, Bitter Almond, Cinnamon Leaf, Ginger, Clove Leaf, Clove Bud (Rose 5% and Jasmin 3%, but not going to use those for a test batch) and some cedar and rosemary that probably don't have enough left.
Of course I also have the lavender-ish oil that I'm assuming is lavandin and that seems to fade as well.
I'm definately going to stick with Blood Orange to test. Maybe Orange 7x? Although I thought folded orange was supposed to fade less? (that's why I didn't use it last time) Does anyone have massive fading issues with one of the above? I haven't had time yet to test all of them, certainly not in a long-term setting.

 

[szaza]

So... since I'm not going to make confetti soap any time soon, I thought I might as well do a smelling test at 4 weeks to see if there is a noticable change.

Right after unmolding, the soaps of condition 1 (added to soap at trace without anchoring) were by far the strongest smelling ones. Probably because the EO didn't mix well with the soap it was all concentrated in one spot and smelled strong. Condition 1 was probably the worst mixed one, as the others were all mixed with an anchoring ingredient (2 & 3) or mixed properly after gel/cook (4).

Now, after 4 weeks, blood orange and lavandin faded quite a bit already, while the lemongrass is still quite strong. The soaps of condition 4 smelled more intense than the other 3 soaps and the difference was even bigger when the soaps were being used to wash hands (my hands have never been this clean).
There was a slight difference between conditions 1, 2 and 3, but this was mainly a difference in which component came through rather than intensity of the smell.
My boyfriend also helped me smell and although we didn't agree on everything, the differences stated above were really clear to both of us.

For now my conclusion would be that HP is best for preserving EO's and that anchoring ingredients don't really make a difference, except a subtle change in which smelly components are a little more dominant. I'll try to come back to it in a few weeks and see if there is any change.

PS. I was able to verify that my mistery "I think this is Lavandin EO" bottle is legit lavandin EO. Score

 

[penelopejane]

I really don’t think you are going to get a thorough mixing by putting batter into a mold then adding the EO and trying to mix it. Better to pour the right amount of batter into a container and then add EO and stickblend it.

 

[szaza]

I really don’t think you are going to get a thorough mixing by putting batter into a mold then adding the EO and trying to mix it. Better to pour the right amount of batter into a container and then add EO and stickblend it.

Thanks! I'll keep it in mind if/when I try again

 

[KimT2au]

If you wanted to get an idea about which level of fragrance works best etc, mix into batter at the lowest level. Pour batter into mould. Add more fragrance to the remaining batter in the bowl/jug, pour into next mould etc. If you want to be exact about your fragrance levels you are going to need to work out the amount you will use when you pour into a mould and work out what the additional fragrance needed is for the batter remaining. Does that make sens? I feel like I have not explained myself well.

 

[szaza]

Thanks for the input @KimT2au ! (your explanation was very clear by the way, so no worries) I'm not really looking at fragrance level, but if mixing EO with clay or beeswax or adding EO after HP cook would work to help the scent stick better. I've always tried to "anchor" in one way or another, while I'm really not sure if it even helps.. So I thought I'd do an experiment to find out, but turns out my experiment was flawed in many ways

Your comment did make me realize/remember that the maximum EO levels are higher in CP than in HP soap, while in this "experiment" I used 3% for all soaps, both CP and HP. Maybe that would explain why the CP soaps smell less and the HP? Though I would have thought that since the CP soap wasn't mixed properly and had all the EO concentrated in the bottom of the soap it would smell more (which was the case right after unmolding).

 

[szaza]

Almost 8 months later I'm about to grate these babies up and thought I'd do another update.
I've been smelling them regularly over the past months and these are the things that I noticed:
1. the difference between gelled CP and HP stays. At about 6 months the HP still smelled the way I would want a soap to smell while the gelled CP soaps had all faded a lot. At 8 months the HP has also started to fade, especially the lavandin one, it barely has a whif of smell left just like the CP ones. I feel it's the 'fresh' component of the blood orange and lemongrass that really preserve better with HP.
2. French green clay is not the way to go for anchoring scents. Maybe bentonite is different (it's hard to come by here) but the soaps with french green clay had less scent, if any left at all.
3. When washing, the intensity of the scent is just a bit less than when smelling the dry soap. I had hoped the clay would have soaked up the smell and set it free when washing, but nothing..
4. Since the soap wasn't mixed well, there was one side on each soap that smelled more than the other. I cured the soaps with the smelly side facing up, covered by a cloth, but after several (4-5?) months, the tops had faded and the bottoms hadn't which inversed the 'smelly' side. This makes me think airflow has a big impact on scent retention and packaging soaps at around 3 months might have more influence on scent than adding an 'anchor'.
5. Although the difference between EO's just added at trace and added in melted beeswas at trace isn't big, I feel like the soaps where the EO's were added in beeswas at trace smelled a little bit sweeter, so I might just keep that idea if I want to work with floral or other sweet scents.
6. One last remarkable observation is that at 8months, there seems to be a difference in lather, where the soaps with beeswax mixed with EO's seem to have a more creamy lather with smaller bubbles, though all the soap had the same amount of beeswax added at trace, the way it is added might have an influence? I'm a bit confused about this one.. maybe the beeswax/EO blend was a bit colder which made the beeswax solidify in the soap batter and avoid any of the beexwax being saponified? I have one soap recipe where I add beeswax at trace which I made twice and also got very different results with exactly the same recipe..
Last thing, the lather of this recipe is really big and fluffy and my hands are not dry at all after washing with it 12 times in a row. So if anyone is looking for a vegetarian/palm free recipe (not vegan, but I guess you could try to replace the beeswax with carnauba or candellila?), feel free to use it though keep in mind these have been curing for 8 months, I think they were just decent at 4 weeks.