Effects of additives on orange EO scent retention

[Mobjack Bay]

I’m spending some time this month testing FOs and EOs for acceleration and scent retention over the longer term. Here’s a set of test soaps I made to follow scent retention of 6x orange essential oil (Camden Grey) at 3% ppo. For each soap, I mixed 1/4 tsp of additive with the EO and let the mixture sit for two hours before I made each individual soap (40 g). From left to right for each row, additives are as follows:

top row: colloidal oats, ground calendula petals, no additive
middle row: tapioca, cornstarch, arrowroot
bottom row: white kaolin clay (BB), French green clay (Frontier), rose clay (BB)


At this point, I can’t tell the soaps apart based on scent strength, but the color differences for the starchy additives are interesting. The whitest soap in the middle is the one with cornstarch. I would say the next whitest is the kaolin clay, although it has a little bit of a grey tinge (lower left).

ETA: soaps were made on 4 Jan. 2021

 

[HowieRoll]

Interesting experiment and I look forward to hearing more about the results down the line. Thanks for sharing!

 

[AliOop]

Very interesting experiment, and thanks for sharing it!

 

[Vicki C]

Thanks for doing this - I always feel let down with citrus EOs in CP.

 

[Mobjack Bay]

Thanks for doing this - I always feel let down with citrus EOs in CP.

Me, too. I’ve had much better luck with scent retention when using orange wax, as described in this thread:
https://www.soapmakingforum.com/threads/orange-peel-wax.75139/

 

[Zing]

Thanks for doing this.

 

[Peachy Clean Soap]

Wow Thx so much great info & interesting' i'm looking forward to finding out which scent had the staying power w/ a particular additive.

 

[Adobehead]

rose clay (BB)

Wow, that is some dark rose clay! It is beautiful, do you mind saying how much you used? 1 teaspoon per pound of oils? or more?

 

[Mobjack Bay]

@Adobehead In order to give the additives a fighting chance, the plan was to use them at 1 tablespoon ppo. Then I got sidetracked from my written instructions, used 20% less batter for each soap, and ended up with the additives at 4 tsp. ppo. Even when I give myself instructions, I still can’t follow them!

 

[Adobehead]

@Adobehead In order to give the additives a fighting chance, the plan was to use them at 1 tablespoon ppo. Then I got sidetracked from my written instructions, used 20% less batter for each soap, and ended up with the additives at 4 tsp. ppo. Even when I give myself instructions, I still can’t follow them!

me neither!
but thanks!

 

[Mobjack Bay]

It’s still early, only 12 days since I made the soaps. Interestingly, I’ve noticed that my perception of scent intensity changes rapidly when I’m smelling the same scent in series. The scent in the first bar I sniff always seems the strongest, the second bar seems a little weaker and then by the third and fourth I’m asking where the scent has gone. To compensate, I started off with a different bar for each of the sniff checks I did over the last two days. At this point, all bars smell nice and I can’t tell them apart based on scent intensity.

 

[Becky1024]

It’s still early, only 12 days since I made the soaps. Interestingly, I’ve noticed that my perception of scent intensity changes rapidly when I’m smelling the same scent in series. The scent in the first bar I sniff always seems the strongest, the second bar seems a little weaker and then by the third and fourth I’m asking where the scent has gone. To compensate, I started off with a different bar for each of the sniff checks I did over the last two days. At this point, all bars smell nice and I can’t tell them apart based on scent intensity.

Try sniffing some coffee beans between each soap. It really works!

 

[linne1gi]

I’m spending some time this month testing FOs and EOs for acceleration and scent retention over the longer term. Here’s a set of test soaps I made to follow scent retention of 6x orange essential oil (Camden Grey) at 3% ppo. For each soap, I mixed 1/4 tsp of additive with the EO and let the mixture sit for two hours before I made each individual soap (40 g). From left to right for each row, additives are as follows:

top row: colloidal oats, ground calendula petals, no additive
middle row: tapioca, cornstarch, arrowroot
bottom row: white kaolin clay (BB), French green clay (Frontier), rose clay (BB)
View attachment 53124

At this point, I can’t tell the soaps apart based on scent strength, but the color differences for the starchy additives are interesting. The whitest soap in the middle is the one with cornstarch. I would say the next whitest is the kaolin clay, although it has a little bit of a grey tinge (lower left).

ETA: soaps were made on 4 Jan. 2021

I did an experiment back in October. I had just enough of soap batter for 2 soaps and I wanted to see if kaolin clay added to fragrance does actually help preserve the scent. I colored one soap pink and one soap green. I used Blood Orange Essential Oil for both soaps. I added 1/8 teaspoon of white kaolin clay to the essential oil and let it "marinate" together for an hour, I added the kaolin clay and essential oil mix to the pink soap. I just added the plain Blood Orange essential oil to the green soap. I unmolded the soaps the next day and placed them on my curing rack for 6 weeks. At the end of 6 weeks, the green soap had absolutely no scent at all, and the pink soap had a great and strong Blood Orange scent. So for me the experiment concluded that kaolin clay does help in scent retention. I am going to try this experiment again in the future to see if it is replicable

 

[Mobjack Bay]

@linne1gi I think it was your post in another thread that made me decide to do the test with the additives ❤. EOs are my personal favorite scents and I would love to find a way to enhance scent retention. After doing some reading about making perfumes and vapor pressure of EOs, I‘m starting to convince myself that the solution to rapid EO loss is likely to be more about physically slowing movement out of the soap than it is about chemically bonding/‘anchoring’ it to anything. Last year someone mentioned that harder soaps with animal fats slow down loss. I‘m guessing that a lower water content might help as well. For this test run, I dried my clay additives in the oven before I mixed them with the EO, hoping that EO soaked into the pore spaces of the clay might have a harder time moving out of the soap compared with EO in the soap itself. To help with scent retention, one SMF member moves EO scented soaps to loosely closed containers once they’ve cured suffciently. I think storage with minimal air flow would help to create a bit of a ‘head space’ which would help to equalize the vapor pressure across the surface of the soap, which should slow down the loss of the EO from the soap itself. It’s not going to work as well as storing the soap in a sealed container, but it sounds like it’s working better than leaving the soaps totally open to the air.

One of my next EO tests will be to compare how storage techniques affect scent retention with some bars I have curing now. So far I plan to put a couple of the bars in a brown paper bag that I will close up tightly and leave sitting on the soap rack, a couple into a plastic clamshell container that will have minimal air circulation and a couple into the freezer after I seal them into a bag with my food saver. I would love to know if anyone has experience freezing cured soap.

 

[linne1gi]

@linne1gi I think it was your post in another thread that made me decide to do the test with the additives ❤. EOs are my personal favorite scents and I would love to find a way to enhance scent retention. After doing some reading about making perfumes and vapor pressure of EOs, I‘m starting to convince myself that the solution to rapid EO loss is likely to be more about physically slowing movement out of the soap than it is about chemically bonding/‘anchoring’ it to anything. Last year someone mentioned that harder soaps with animal fats slow down loss. I‘m guessing that a lower water content might help as well. For this test run, I dried my clay additives in the oven before I mixed them with the EO, hoping that EO soaked into the pore spaces of the clay might have a harder time moving out of the soap compared with EO in the soap itself. To help with scent retention, one SMF member moves EO scented soaps to loosely closed containers once they’ve cured suffciently. I think storage with minimal air flow would help to create a bit of a ‘head space’ which would help to equalize the vapor pressure across the surface of the soap, which should slow down the loss of the EO from the soap itself. It’s not going to work as well as storing the soap in a sealed container, but it sounds like it’s working better than leaving the soaps totally open to the air.

One of my next EO tests will be to compare how storage techniques affect scent retention with some bars I have curing now. So far I plan to put a couple of the bars in a brown paper bag that I will close up tightly and leave sitting on the soap rack, a couple into a plastic clamshell container that will have minimal air circulation and a couple into the freezer after I seal them into a bag with my food saver. I would love to know if anyone has experience freezing cured soap.

I don't store my soaps any particular way at all. I have them all together in a large chest of drawers after they are cured. I have been adding clay to my soaps for over 5 years now and I am pretty much convinced that using clays really help. One of the things I did notice is the time spent "marinating" - it appears the clay needs time to soap up the fragrance. The scents that I leave soaking overnight seem to be the longest lasting. Unfortunately I don't have a lot of room for storage either. Just one little section of my guest bedroom. And I make soap in my dining room. I am definitely interested in your experiment and I hope you tag me or somehow get it to my attention. I am particularly interested in the non clay additives. I did try arrowroot powder and cornstarch a few years ago, but it didn't seem to give me scent retention. Of course I didn't make an actual experiment, this is just anecdotal. Anyway, I appreciate your reply

 

[Mobjack Bay]

It’s been just over two months since I made test soaps to test the effects of additives on orange EO scent retention. The good news is that they all still smell like orange EO. I’m actually quite pleased because this is the first time I used a folded (6x) orange EO. There are no detectable differences in scent strength among bars, including the one with no additives. The colors of the bars don’t seem to have changed much, but lighting is always an uncontrolled variable, so I took photos under two different lighting conditions for comparison. The soap with cornstarch still looks the whitest and the green and rose clay colors are still gorgeous.

Again, from above:
top row: colloidal oats, ground calendula petals, no additive
middle row: tapioca, cornstarch, arrowroot
bottom row: white kaolin clay (BB), French green clay (Frontier), rose clay (BB)

Here’s the original photo:



and the new photos:




note: post edited for clarity

 

[linne1gi]

It’s been just over two months since I made test soaps to test the effects of additives on orange EO scent retention. The good news is that they all still smell like orange EO. I’m actually quite pleased because this is the first time I used a folded (6x) orange EO. Relative to the additives, there are no differences in scent strength among bars that I can detect. The colors of the bars don’t seem to have changed much, but lighting is always an uncontrolled variable, so I took photos under two different lighting conditions for comparison. The soap with cornstarch still looks the whitest and the green and rose clay colors are still gorgeous.

Again, from above:
top row: colloidal oats, ground calendula petals, no additive
middle row: tapioca, cornstarch, arrowroot
bottom row: white kaolin clay (BB), French green clay (Frontier), rose clay (BB)

Here’s the original photo:

View attachment 54842

and the new photos:

View attachment 54845
View attachment 54846

Thanks for posting @Mobjack Bay, I noticed that one of your soaps has no additive, how does that one smell now 2 months later?

 

[Peachy Clean Soap]

Thanks for posting @Mobjack Bay, I noticed that one of your soaps has no additive, how does that one smell now 2 months later?

Wow love your experiment. interesting color findings being / staying white with the cornstarch. Ive found out using most of the citruss scents orange is the fastest fleeting of them' in EO, which x4 orange EO did you use? Lime EO seams to have a great sticking power, Love using it. Love your Findings very informative.

 

[dibbles]

How does the bar with no additives compare to the others?

 

[Mobjack Bay]

@linne1gi and @dibbles

Sorry if I wasn’t clear enough. The soap made without an additive smells just like the others, except that the soap made with the calendula powder also smells a little like straw.

@Peachy Clean Soap my orange EO is 6x from Camden Grey in Florida.