Using a mixer to incorporate scent in HP soap

[songwind]

I have a couple of shaving soap scents that make use of low-flashpoint essential oils (citrus oils & rosemary, specifically).

Waiting for the soap to be (near) cool enough to add the EOs results in a very stiff product, even with sodium lactate in the formula and added glycerin. This week I snapped off a spatula in it.

I'm curious if anyone has used a mixer on HP soap to incorporate additives, and if it's possible to do so without creating a "whipped" character.

 

[reinbeau]

I've had so many soapers tell me that flash point doesn't make a difference - I totally disagree, but.....what I would do is get it down to about 150° and incorporate the scent - and see how well it sticks after it's finished. Do a small test batch. I think you're going to end up with whipped soap otherwise.

 

[songwind]

I made sufficient mistakes early on that I can say that flash point definitely makes a difference. Not an all-or-nothing difference, but significant.

 

[DeeAnna]

Flash point is simply the temperature at which a flammable liquid will support a flame when a spark is introduced into the vapor space above the liquid. Not all liquids, including some scents, have a flash point, so a better measure of the volatility of any liquid -- how fast it will evaporate -- is to look at its vapor pressure at the temperature(s) of interest.

That said, if you are comparing flammable fragrances, then as a general rule, the lower the flash point, the more likely the fragrance will evaporate quickly at lower temperatures. But people put way too much importance on the specific flash point temperature. The "common wisdom" appears to be that if a fragrance is added to a soap or lotion BELOW the fragrance flash point, then that will protect the fragrance from evaporating. That isn't correct thinking. If you can smell the fragrance, it is volatilizing, even if the temperature of the fragrance is well below its flash point. I add my fragrances at a cool temperature too, but how the scented product is handled and packaged is also important to protect the fragrance.

To answer your question, Eric, yes, I have used my trusty Kitchenaid mixer to incorporate fragrance and glycerin into my shave soap batches. I let the soap paste cool to "just a little warm", put it into the mixing bowl, mix on low until the paste softens, add the scent, and mix on low until everything is well mixed. I also think it helps the soap be a little better mixed and look more even. Just keep the mixing speed low and only long enough to get the job done. I'm not noticing any "whipped soap" thing happening.

 

[songwind]

That said, if you are comparing flammable fragrances, then as a general rule, the lower the flash point, the more likely the fragrance will evaporate quickly at lower temperatures. But people put way too much importance on the specific flash point temperature. The "common wisdom" appears to be that if a fragrance is added to a soap or lotion BELOW the fragrance flash point, then that will protect the fragrance from evaporating. That isn't correct thinking. If you can smell the fragrance, it is volatilizing, even if the temperature of the fragrance is well below its flash point. I add my fragrances at a cool temperature too, but how the scented product is handled and packaged is also important to protect the fragrance.

Oh, I definitely get that. I just want to give it every chance I can to stay in the soap. I think the soap would be unmixable if I let it get down to 105 (to match the lime & lemon EOs, for instance). But I do let it get down to 115 or so.

To answer your question, Eric, yes, I have used my trusty Kitchenaid mixer to incorporate fragrance and glycerin into my shave soap batches. I let the soap paste cool to "just a little warm", put it into the mixing bowl, mix on low until the paste softens, add the scent, and mix on low until everything is well mixed. I also think it helps the soap be a little better mixed and look more even. Just keep the mixing speed low and only long enough to get the job done. I'm not noticing any "whipped soap" thing happening.

Looks like I'm buying a cheap hand mixer. I don't think Mrs. Songwind would put up with me using the KitchenAid, even if it is technically mine.

Thanks, DeeAnna. My soap and my shoulders thank you.

 

[reinbeau]

Smelling the fragrance is vastly different than having it poof up into your face - sorry, personal experience tells me to cool that batter and it works for me, so I'll continue to do so.

 

[DeeAnna]

Eric and I are agreeing with you, Reinbeau. If soap is as cool as possible when scent is added => more fragrance in the soap. No arguments there!

 

[HerbalEarthling]

I don't know if this counts but I had to add more lye to a batch. It was still very oily so it wasn't that thick to begin with. I used a beater (not a stick blender but the kind of beater most people use in their kitchen) to incorporate the additional lye water. I say go for it! As long as you're wearing good skin/eye protection and have a beater to sacrifice to soap, you've got nothing to lose! Also, keep it on the slowest setting possible to make sure that you don't paint your walls with soap!

 

[DeeAnna]

Unless I'm missing Eric's point entirely, HE, we're talking about incorporating fragrance into a soap after the HP cook. The soap is firm and saponified, so the only thing that might possibly spatter is the fragrance.

Why would you have to add more lye to a soap batch? If the recipe is calculated correctly, there should be no need to do that. Lye doesn't evaporate like fragrances do.

Also, the beaters of a decent quality mixer are usually stainless steel or, in the case of a Kitchenaid, they are porcelain coated metal. These materials are both resistant to lye, so no sacrifice should be required.

 

[HerbalEarthling]

Unless I'm missing Eric's point entirely, HE, we're talking about incorporating fragrance into a soap after the HP cook. The soap is firm and saponified, so the only thing that might possibly spatter is the fragrance.

Why would you have to add more lye to a soap batch? If the recipe is calculated correctly, there should be no need to do that. Lye doesn't evaporate like fragrances do.

Also, the beaters of a decent quality mixer are usually stainless steel or, in the case of a Kitchenaid, they are porcelain coated metal. These materials are both resistant to lye, so no sacrifice should be required.

My recipe wasn't calculated correctly... I was simply giving my experience with the consistency of the HP not being too much for a blender to handle.

Maybe I'm just overly cautious but I don't use anything for food that I've already used for soap. For me, it's just easier. Plus, I'm fortunate enough to have a portion of my basement for soap making and I hate trudging up and down the stairs with materials/tools.

And no matter what, whether it's lye or fragrance/essential oil, you don't want that stuff in your eyes. In my opinion, you should always wear at least eye protection when using any kind of blender because of the potential spatter.