# Cornstarch



## Guest (Jun 8, 2011)

I have noticed when looking at different soap blogs that some of them put cornstarch in their CP soap.  Any ideas why?


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## Relle (Jun 18, 2011)

Cornstarch is suppose to anchor citrus scents.


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## trishwosere (Aug 20, 2011)

If I am soaping with citrus scents I *always* use corn starch as an anchor,It definitely works and IMO gives the soap a more smoother feel


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## Fragola (Nov 4, 2011)

How is cornstarch mixed together with the EO ? And how much cornstarch ?

Just guessing, I'd mix it with a little oil (since EOs aren't soluble in  water), but not sure it's the best choice.

P.S. _Just noticed I am talking in the wrong forum  :? _


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## trishwosere (Nov 4, 2011)

I use about 1/3-1/2 (max) tablespoon mixed with a little oil taken from main batch (olive or almond I use) I mix to a fine consistency then add my FO to this and then mix back into main oils. *Don't* use too much cornstarch because IMHO it can make your soap powdery. 

edited to change teaspoon to tablespoon, my bad


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## Hazel (Nov 4, 2011)

Fragola said:
			
		

> P.S. _Just noticed I am talking in the wrong forum  :? _



Thanks for pointing this out. Moved it.


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## Maythorn (Nov 4, 2011)

I had the idea that powders might absorb scent.  Does anyone know how or why cornstarch anchors a scent?  I would be willing to try half a teaspoon and see what it's like.


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## Fragola (Nov 4, 2011)

Same explanation seems obvious to me.

I was just thinking today that charcoal probably works even better. If it only was white instead of black


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## Stacey (Nov 4, 2011)

trishwosere: you use this for your FO's too?  Not just Citrus EO?  That's very interesting.  

As a general rule do you always do it or just with known non-sticking FO's?


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## trishwosere (Nov 4, 2011)

I always thought of charcoal as a neutralizer as in odour-eaters etc.,

I don't know why cornstarch anchors but it definately absorbs the scent. I had it recommended to me to use 1tablespoon PPO but I found this amount made my soap chalky/powdery so I cut it down to about 1/3 -1/2 that amount max', and it works just fine


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## paillo (Nov 4, 2011)

i use cornstarch to anchor citrus scents, and also to boost staying power for fos that tend to fade. and i too have cut the quantity from about 1 T ppo to about half that.


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## trishwosere (Nov 4, 2011)

Stacey said:
			
		

> trishwosere: you use this for your FO's too?  Not just Citrus EO?  That's very interesting.
> 
> As a general rule do you always do it or just with known non-sticking FO's?



I don't do it always no, but if I'm soaping one of my favourite citruses that I know is a fader then I use the cornstarch.I have a tangerine  and also a blood orange that smell divine, but they unfortunately fade, so I use the cornstarch method with them, and also with the exception of litsea I use it in the majority of citruses. I've never thought about using it in any other FO apart from citruses...this is something I shall have to try soon :wink:


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## debbism (Nov 4, 2011)

I wonder if you can sub in arrowroot or another starch.  My daughter is allergic to corn - cornstarch irritates her so we removed it from the lotion bars and replaced with arrowroot.  

We can also easily get rice starch, potato starch etc.....all from the asian market.  like 2-3 bucks for a pound


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## Fragola (Nov 4, 2011)

Or colloidal oatmeal.


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## dieSpinne (Nov 4, 2011)

I have heard Orris Root powder is also an excellent scent fixative and has a very slightly more exfoliant texture than cornstarch.


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## soapbuddy (Nov 4, 2011)

I prefer oatmeal. Orris root makes me seriously itch.


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## dieSpinne (Nov 4, 2011)

soapbuddy said:
			
		

> I prefer oatmeal. Orris root makes me seriously itch.



Fair enough!  There are always going to be individual sensitivities and everyone should always check to make sure that their ingredients are not going to affect the intended user.

That being said, soapbuddy, are you otherwise allergic to Irises or other members of the Iris family?


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## Fyrja (Nov 4, 2011)

I was curious about this and found another post on this subject.


The usage suggested on this was 1 tablespoon PPO on the other post.  I see some on here suggesting less though.  I used 1 tbsp ppo on a batch of soap I made last night.  I hope it's ok, I'm all worried now!

I did notice one thing though, it seemed like my soap traces much faster with cornstarch in it, and I think I got a partial gel even though I soaped really cool.  

Has anyone else noticed this with cornstarch?

http://www.soapmakingforum.com/forum/viewtopic.php?p=153634&sid=7ef4aae2257ec829f4cbb458d09646dd


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## Fragola (Nov 4, 2011)

The more I am reading this thread, the more I get the idea that (if possible), essential oils should be mixed with a little oil and whatever powder gets into the soap (pigments, herbs, exfoliants, etc.).


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## Fragola (Nov 4, 2011)

Fyrja said:
			
		

> The usage suggested on this was 1 tablespoon PPO on the other post.  I see some on here suggesting less though.  I used 1 tbsp ppo on a batch of soap I made last night.  I hope it's ok, I'm all worried now!



Very confusing. Everybody here  seems to be using much less  :? 

You are possibly the best person who can shed light on the matter. 

By getting a little piece of soap, washing your hands (or gloves - if it still zaps) and let us know if it feels chalky / powdery :wink:


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## Maythorn (Nov 4, 2011)

I just posted a thread entitled "Oatmeal," last week where I reported that bars without oatmeal powder smelled stronger, same scent same recipe.

I also don't understand how baking soda in a bath salt recipe wouldn't weaken the scent. :?


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## soapbuddy (Nov 4, 2011)

dieSpinne said:
			
		

> soapbuddy said:
> 
> 
> 
> ...


Good question! I don't know. They don't grow here, so I haven't been in contact with any.


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## Fragola (Nov 4, 2011)

> I also don't understand how baking soda in a bath salt recipe wouldn't weaken the scent.


I never bought that myth about baking soda being an all - smell absorber.


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## Hazel (Nov 4, 2011)

I've had good luck with baking soda absorbing odors. Who says it's a myth?


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## Fyrja (Nov 4, 2011)

I just cut the bars and tested a little piece.  It's still zappy, but from what I can tell it's not that powdery.  In fact the lather is gorgeous for bars that are just one day old.  Big bubbles and when you work with it it gets really silky.  I only imagine it'll get better as it cures.  I'll test again when the bars are less zappy and let you know how it goes.

Oh and I also checked the recipe, I had noted that I only used 4 scant tbsp for 5 pounds of oils.  So maybe it'll work out after all.  Only time will tell.


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## Fragola (Nov 5, 2011)

I've been pondering about cornstarch and come up with a new theory ... corstarch mixed with water turns to custard. Maybe this custard forms a barrier that stops the lye from touching the EOs. Other thickening additives (like xanthan) may have the same effect.

If that is true, cornstarch could be used to prevent seizure, for those fragrances (or other ingredients) everybody fears to use.

For it to work properly, it probably needs to be added last (at trace) and make sure you don't blend too much. If possible just use a whisk.



> I've had good luck with baking soda absorbing odors. Who says it's a myth?


Of course you did, that's part of the myth 

In my mind, all 1-cure-for-all recipes fall under the _myth _category. Which doesn't mean they're wrong. In fact, there's always a grain of truth to it. 

I am sure baking soda has valid uses, but there's so much inconsistent information available on the topic that I can't make any sense of it.

Another piece of the myth I just stumbled upon:


> Baking soda neutralizes odors chemically, rather than masking or absorbing them.


http://www.enotes.com/baking-soda-reference/baking-soda


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## trishwosere (Nov 5, 2011)

Fragola said:
			
		

> corstarch mixed with water turns to custard.



Don't fancy your custard much lol


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## Hazel (Nov 5, 2011)

Fragola said:
			
		

> > I've had good luck with baking soda absorbing odors. Who says it's a myth?
> 
> 
> Of course you did, that's part of the myth



Huh? How can finding out from personal experience that baking soda did absorb odors be part of the myth that baking soda doesn't aborb odors? 



			
				Fragola said:
			
		

> In my mind, all 1-cure-for-all recipes fall under the _myth _category. Which doesn't mean they're wrong. In fact, there's always a grain of truth to it.
> 
> I am sure baking soda has valid uses, but there's so much inconsistent information available on the topic that I can't make any sense of it.



I'm sure baking sode isn't a cure for all but I use it frequently for various household and personal items. It's cheap and it works which is all I care about but this is just my opinion. Perhaps I'm wrong in stating it aborbs odors. Maybe I should say it neutralizes odors.  :wink: 

Perhaps it isn't as effective as advertising wants people to believe. I don't know why it helps to absorb/neutralize odors. I do know that over time (1 year +), bath fizzies/bombs do lose their scent compared to bath salts. (This wasn't a deliberate experiment. They got shoved to the back and I forgot they were there.    ) They also barely fizzed which tells me there is a shelf life for them.


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## Fyrja (Nov 5, 2011)

Fragola said:
			
		

> I've been pondering about cornstarch and come up with a new theory ... corstarch mixed with water turns to custard. Maybe this custard forms a barrier that stops the lye from touching the EOs. Other thickening additives (like xanthan) may have the same effect.
> 
> If that is true, cornstarch could be used to prevent seizure, for those fragrances (or other ingredients) everybody fears to use.
> 
> For it to work properly, it probably needs to be added last (at trace) and make sure you don't blend too much. If possible just use a whisk.




I've always used cornstarch as a thickening agent for sauces and gravies.  I make it into a slurry and add it to hot liquid, and voila it thickens.

It does make sense though that it would thicken soap, since that's what it did to mine.  I added with with clay at light trace, blended it in.  The soap seemed to thicken up quickly after that to the consistency of a thinner pudding.  I poured the first layer, and then after that I was spooning and smoothing layers in.


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## Fragola (Nov 5, 2011)

Hazel said:
			
		

> Huh? How can finding out from personal experience that baking soda did absorb odors be part of the myth that baking soda doesn't aborb odors?



Not you finding out for yourself, but rather sharing your belief. The shared personal experience or belief of many of people is the cornerstone of any myth.

What confuses me here is the generalization. I am certain that baking soda does neutralize a certain range of odors. But I have no clue what those are.



> I do know that over time (1 year +), bath fizzies/bombs do lose their scent compared to bath salts.


Probably has something to do with the recipe as a whole. This debate started with a claim that baking soda in bath salts does not weaken the scent.



			
				Maythorn said:
			
		

> I also don't understand how baking soda in a bath salt recipe wouldn't weaken the scent.





> They also barely fizzed which tells me there is a shelf life for them.



From what I hear, fizzies have both baking soda and citric acid mixed in. Those probably react together over time, slowly losing their fizzle. That reaction could possibly accelerate the loss of fragrance through evaporation.

Final question remains ... would baking soda ancor scents in soap?


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## Maythorn (Nov 5, 2011)

Hmm then I better not add cornstarch with fragrances that move fast or the soap would be so thick it would be pitiful!


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## Hazel (Nov 5, 2011)

Fragola said:
			
		

> Not you finding out for yourself, but rather sharing your belief. The shared personal experience or belief of many of people is the cornerstone of any myth.


It’s not a belief. Belief is the acceptance of a concept as true which hasn’t or can’t be proven by physical means. By finding out through personal experience, it goes from belief to knowledge based upon using the product over time and discovering the results for myself. If I accepted the statement “baking soda doesn’t absorb odors” as true without ever personally trying it then that would be a belief. 

I can’t state that baking soda absorbs/neutralizes all odors because I don’t know if that is true. I just know that it has worked for me for certain things. As you have stated, generalization is confusing but unfortunately many people do make generalizations out of ignorance or for propaganda purposes.    

I don’t use baking soda in bath salts so my personal experience could possibly help contradict the claim that it doesn’t weaken scents over time. On the other hand, it wasn't the same FO I used in the bombs so it really doesn't contradict the claim. It could have just been a stronger FO in the salts.

My belief about the loss of fizz is the bombs had absorbed moisture which did cause them to slowly interact over time (as you mentioned), although I can’t prove it.  



			
				Fragola said:
			
		

> That reaction could possibly accelerate the loss of fragrance through evaporation.



Good point. 

I personally don’t believe baking soda would anchor scents in soap. But I’m not going to do an experiment to prove it.


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## Fragola (Nov 5, 2011)

> Hmm then I better not add cornstarch with fragrances that move fast or the soap would be so thick it would be pitiful!


Quite the opposite could be true (this is only a speculation).

We agreed that cornstarch thickens a mixture, because it mixes with the water and thickens it. That could probably be compensated by slightly increasing the amount of water. 

But the same process could block the lye from reacting with the fragrances, which I believe is the process that makes the soap seize. Especially if you mix in the fragrance very gently rather than blending at full speed.


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## dcornett (Nov 7, 2011)

I use corn starch in a couple of my soaps, and when I do I use a T ppo. I've never had any problems with it accelerating trace or being crumbly, or powdery. It actually adds a nice silky/satiny feel to the soap. But everyone has their own tastes, so that's where the experimentation comes in.


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## Angelkarling (Nov 8, 2011)

I'm so glad I stumbled on this post. I'm going to try a batch of tea tree soap again using corn starch and maybe the scent will stick!


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## Hazel (Nov 8, 2011)

I wonder if arrowroot would work, too. I think I'll try this unless someone knows for sure it doesn't work.


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## zeoplum (Apr 5, 2012)

Now that this is a few months old, I'm wondering if anyone was inspired to go and test some of this out.  If so, what did you find?  Any surprises?


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## Tienne (Dec 22, 2013)

Fyrja said:


> I did notice one thing though, it seemed like my soap traces much faster with cornstarch in it, and I think I got a partial gel even though I soaped really cool.
> 
> Has anyone else noticed this with cornstarch?
> 
> http://www.soapmakingforum.com/forum/viewtopic.php?p=153634&sid=7ef4aae2257ec829f4cbb458d09646dd



Cornstarch mixed in water or oil becomes a non-Newtonian fluid. It will "stiffen" when aggitated quickly (as in being stickblended) but will "relax" again once it's stirred slowly. Also, cornstarch molecules unravel when heated and the long molecules will criss-cross each other forming a molecular lattice or mesh. That's how it thickens stuff. (Sauces, etc) The heat generated by the lye+oil reaction could be all it takes to make that lattice-making process occur, hence thickening the batter. That thickening would not be a saponification, but more of a "mechanical" thickening.

That same molecular lattice, is what I think helps anchor scent. The scent molecules become trapped in the lattice and in theory, the larger the scent molecules, the better they would be anchored, so any degress of scent fixation would be dependent on which scent is being used and the size of it's molecules. 

Cornstarch is also a carbohydrate, a chemical sugar. I think that is what makes the soap batter prone to heating up, as any sugars in soap would do.


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## OliveOil2 (Dec 22, 2013)

Not wanting to be off topic, but this post has me wondering if denatured salt would hold scent? I have used this to hold the scent in bath salts. But worry that is might have the opposite effect, since salt and vinegar work to remove scent from bottles that I recycle from essential oils.


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## Relle (Dec 22, 2013)

Tienne said:


> Cornstarch is also a carbohydrate, a chemical sugar. I think that is what makes the soap batter prone to heating up, as any sugars in soap would do.


 
 So soap does make you fat then :razz:, better stop using it .


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## Tienne (Dec 22, 2013)

Relle9 said:


> So soap does make you fat then :razz:, better stop using it .


Not just fat, but superfat!


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## kryse13 (Dec 22, 2013)

When life gives you lemons, you make lemonaid.
When life gives you fat... make soap!


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## Tcra (Jun 14, 2020)

Hi, i was wondering how i can se starch to anchor scents in hot process soap making? Has anyone here done that?


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## shunt2011 (Jun 17, 2020)

Tcra said:


> Hi, i was wondering how i can se starch to anchor scents in hot process soap making? Has anyone here done that?



This post is from 2011-2013 and most of the posters haven't been here in years.  You'd be better off to start a new thread.   Since you are new be sure to go to the introduction forum and tell us a bit about yourself.   

In my experience, I haven't found anything that will make a fragrance stick.   I test most new fragrances in small batches to see how they behave.  If they don't stick for 6 months I don't make it.


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