Gel Phase and EO Scents

I'm just wondering how hot on average gel phase gets and how this effects EO scents.
Do those with higher flashpoints retain scent through gel, and those with low flashpoints lose scent?
Peppermint has a high flashpoint, but I notice my bar's scent is mild.

Also, would attempting to prevent gel retain more scent? Would adding more EO than a recipe calls for maintain more scent if I do gel?

thank you

NO.

Flashpoint has almost nothing to do with soapmaking at all. It's the point at which the vapors if exposed to flame or spark can ignite. That's it. Flashpoint is only listed for saftey for transporting and for making candles (not even all candles, just gel candles).

That's it.

Do NOT use more than the maximum recommended amount. Yes, it would probably smell stronger, and it would also be much more irritating.

Flash point, boiling point, whatever - you can't escape the fact that low 'flash point' essential oils do not survive gel, or even saponification, properly, without a lot of help with fixatives or whatever. I get a kick out of people who get hung up on the terminology but ignore the actual results.

Low flash point EOs don't do well in gel phase (no matter what you want to call them or what the reason for it is). I personally prefer to put them into HP batches, where I do lower the temp quite a bit before I add them. That thought seems to make some people fly into a rage that I say it, but it works for me and I'll bet it will work for you, too. If you want to use them in CP, find an appropriate anchor, clay, whatever, or base note that will help the fragile top note come through.

reinbeau said:

Flash point, boiling point, whatever - you can't escape the fact that low 'flash point' essential oils do not survive gel, or even saponification, properly, without a lot of help with fixatives or whatever. I get a kick out of people who get hung up on the terminology but ignore the actual results.

Low flash point EOs don't do well in gel phase (no matter what you want to call them or what the reason for it is). I personally prefer to put them into HP batches, where I do lower the temp quite a bit before I add them. That thought seems to make some people fly into a rage that I say it, but it works for me and I'll bet it will work for you, too. If you want to use them in CP, find an appropriate anchor, clay, whatever, or base note that will help the fragile top note come through.

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I would agree with you on the "hung up on terminology" part. But I have to respectfully disagree with the low flash point EO's not surviving Gel. Here's my reasoning.

I CPOP almost everything besides my salt soaps to insure a full gel. They're in a oven at 170 for a hour, including my CM soaps. They get hot, no doubt.

Yet here are some low flashpoint EO's that I've used that come through strong and I just went and smelled one bar that's 7 months old and still smells strong.

Bergamot - 136F
Rosemary 105F
Tea Tree 135-142F
Black Pepper 138 to 150F
Lemongrass 133 to 135F
Sandlewood 131 to 133F

I'm well over those flash point levels all the time soaping, yet they hold up really well. I don't use clay, I use the sandlewood as a base note in a few blends .

I'm not raged by your usage, :razz: and I'm not saying you're wrong. I find more everyday that people seem to have different experiences while soaping. I just don't find any relation to the flashpoints being a deciding factor in what comes through in my scent. To me, it's always been more of the scent group...ie citrus.

Yes, that's a good point, it is the citrus scents mainly that don't survive. Except lemongrass! So I amend my rant to be mainly the citrus. Thank you for helping me hone that down to the real issue

Lemongrass is technically not a citrus, it is a grass:

Lemongrass Cymbopogon, commonly known as lemongrass is a genus of about 45 species of grasses, native to warm temperate and tropical regions of the Old World and Oceania. It is a tall perennial grass. Common names include lemon grass, lemongrass, barbed wire grass, silky heads, citronella grass, cha de Dartigalongue, fever grass, tanglad, hierb…
en.wikipedia.org
Scientific name: Cymbopogon
Biological classification: Genus
Consists of: Cymbopogon citratus · Cymbopogon nardus · Cymbopogon flexuosus · Cymbopogon schoenanthus · Cymbopogon martinii
Belongs to: Poaceae

However, I am of the "some EOs don't stick well" club. The ones I have trouble with coincidentally have low flash points. I am not saying that correlation implies causation. But some don't stick well. Lemongrass serves the purpose well when you want a citrus note in a bar soap, though.

Somebody did an experiment, I think on this forum, that made a compelling case for saponification being the primary reason for EOs fading or morphing, rather than the hottest temperature that the soap mixture attained. I'd like to guess DeeAnna as she's our resident soap scientist. Based on that, the best way to ensure your EOs last would be to switch to hot process and add the EO at the end of cook, just before molding.

I mostly use EO and I mostly gel my soaps. I will up citrus EOs as they are most prone to fading, IMO, but none of the others. My soap remains fragrant up to about 1 year. I have not found that clay or cornstarch "anchors" scent but YMMV.

judymoody said:

Somebody did an experiment, I think on this forum, that made a compelling case for saponification being the primary reason for EOs fading or morphing, rather than the hottest temperature that the soap mixture attained. I'd like to guess DeeAnna as she's our resident soap scientist. Based on that, the best way to ensure your EOs last would be to switch to hot process and add the EO at the end of cook, just before molding.

I mostly use EO and I mostly gel my soaps. I will up citrus EOs as they are most prone to fading, IMO, but none of the others. My soap remains fragrant up to about 1 year. I have not found that clay or cornstarch "anchors" scent but YMMV.

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Yeah, I would have to agree that it has to do more with the chemical reaction happening during saponification, than just temperature. I would have to guess that some chemical makeups of EO's are just better able to survive the process.

Just an observation from the last two bars I made:

Both contained the same carrier oils. Same 1.5oz of EOs. One used peppermint, the other lemongrass. The lemongrass EO was in (french green) clay, the peppermint was not. I notice after a few days the peppermint doesn't smell strong, whereas the lemongrass smells almost as strong as when in the bottle. This is the first time I have used either EO in a soap, so maybe lemongrass is just strong? But i thought it was interesting clay might help keep the scent (I think someone mentioned that in this or another thread, too). This was also the first time I used clay. I'll have to experiment more and try to see if clay helps hold scent.

I'm agreeing with the general consensus. Flash point does relate to the flammability of a substance, but flash point isn't necessarily a good measure of how volatile a substance is (how fast it evaporates) when it is added to soap. This is true for no other reason than some volatile chemicals do not burn, so they do not have a flash point. Nor does flash point have anything to do with the chemical reactivity of a substance when it is exposed to lye.

DeeAnna said:

I'm agreeing with the general consensus. Flash point does relate to the flammability of a substance, but flash point isn't necessarily a good measure of how volatile a substance is (how fast it evaporates) when it is added to soap. This is true for no other reason than some volatile chemicals do not burn, so they do not have a flash point. Nor does flash point have anything to do with the chemical reactivity of a substance when it is exposed to lye.

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This reminds me, I distil my own water, and always have crud in the bottom after a batch. I assume that's all the gunk from the tap. But in the actual water itself, anything that evaporates at a lower temp than water would be left in the water once the vapor condenses, correct? I know it's slightly off topic but i wanted to "ask the internet" about that and thought of it when you mentioned evaporation of the EOs.

Yes if you distil water, anything contained in it which has a boiling point at or below that of water (solvents for instance) would come over as well. Activated carbon would be a good filter if you are concerned there. When I needed a lot of distilled water I used RO/DI which was more energy efficient. NOw when soaping I just buy a jug of distilled water (refill) when at the grocery store. Unless you are using an otherwise wasted heat source, I think that make s a lot more economical sense.

LBussy said:

Yes if you distil water, anything contained in it which has a boiling point at or below that of water (solvents for instance) would come over as well. Activated carbon would be a good filter if you are concerned there. When I needed a lot of distilled water I used RO/DI which was more energy efficient. NOw when soaping I just buy a jug of distilled water (refill) when at the grocery store. Unless you are using an otherwise wasted heat source, I think that make s a lot more economical sense.

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Thanks. I called my electric company and we did the math together. Distilling one gallon at home costs $.52. At the store they are about $1.20 where i live.

I do use a carbon filter whew.

A jug is a little less than that here but what I am talking about is the "fill your own" things they have - at least they do here. I pay very little per gallon when I bring my own jug. Might be worth keeping an eye out the next time at the store. I'll have to look and see how much it is for sure but my memory has it being quite inexpensive.

Something else to consider (I was schooled as an Engineer so my brain goes here) is that you are adding all of that heat to your house which must be removed again in the summertime - so you pay double basically. In the winter it's not a loss.

LBussy said:

Something else to consider (I was schooled as an Engineer so my brain goes here) is that you are adding all of that heat to your house which must be removed again in the summertime - so you pay double basically. In the winter it's not a loss.

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It does heat the house in the summer, but I just open a window. This area (central coast) of California is 65 almost year round. A hot day is 75 degrees. I literally spend $0 on heating or cooling all year! I have used my heater once in the 6 years I've lived here and have never used cooling.

Well that's awesome for you ... not so much here. It's either too darned cold or too darned hot. I remember talking to a guy on a plane once and I asked what he did. He said he had the most boring job in the world: he was a meteorologist in San Diego. Poor guy!

The jug of distilled water works pretty well for me. I make the shaving soap in 1 lb batches so using ~200 g of water makes a gallon last for what ... 15 batches? If I ever get larger I am sure I will be looking for ways to be more efficient.

LBussy said:

Well that's awesome for you ... not so much here. It's either too darned cold or too darned hot. I remember talking to a guy on a plane once and I asked what he did. He said he had the most boring job in the world: he was a meteorologist in San Diego. Poor guy!

The jug of distilled water works pretty well for me. I make the shaving soap in 1 lb batches so using ~200 g of water makes a gallon last for what ... 15 batches? If I ever get larger I am sure I will be looking for ways to be more efficient.

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I actually purchased the distiller as a "prep" for earthquakes out here. It was in my kit so I decided to use it for soaping, so definitely getting my money's worth. I hear you can distil booze in these! Haven't tried that yet.

In the US, it is not legal to distill alcohol without proper permits and such. However, you could distill your own EOs.

Susie said:

However, you could distill your own EOs.

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We have so many eucalyptus trees here...i need to look into that.

If that has any plastic parts you may want to avoid anything that could be a solvent. A very HOT solvent on plastic may end badly for anything not metal.