My liquid soap has a yeast smell to it.

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MapRef41N93W

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Hello SMF this is my first post on here.

I made a batch of liquid soap using Dr. Bronners as the base (would eventually like to make my own Castille soap in the near future, but decided to just use their soap to start out with) out of oatmeal, honey, herbs, and essential oils. After about 2 weeks, my soap now has a distinct yeast smell to it, almost like sourdough.

I'm trying to figure out why this happened as I thought soap should have too high of a PH for yeast to thrive in. I made the soap by pouring boiling water over oatmeal, herbs (lavender, thyme, basil), and orange/lemon peel and let it soak for a while. I then strained off all the matter (the oats, herbs, etc.) leaving only the milk. I added that to honey, xanthan gel, vitamin e, four thieves essential oil, and castille soap and mixed it up. It worked great for about 2 weeks but now it just stinks of yeast.

I figured it would go bad eventually, but being that honey is an anti-septic I expected to get at least a month before having to toss whatever was left.

Anyone have a clue as to how yeast were able to thrive in my soap?
 
Yeah you basically made a sort of sourdough starter...

That is a very small amount of soap to a whole lot of fermentables. Theres a general rule about limiting additions of organic/vegetable matter to liquid soap, or even solid soap that you make from scratch with lye. You can use even less when mixing with already made soap as you don't have the advantage of the lye and saponification reaction to kill all the nasties. Undiluted honey may be antiseptic, diluted honey is sugar water and ferments quickly to mead or vinegar.

This is actually a really good example of why preservatives are necessary in any mix of water and bacteria/yeast/fungus food.
 
I see thanks. I actually got the recipe online and it didn't mention needing any preservatives so I figured the honey was acting as a preservative. From what I understood, honey being hygroscopic would limit the available water to bacteria in the solution (my mixture was 1/2 cup soap to 1cup oat/honey water and 1/2 cup xanthan gel) apparently that wasn't the case.

Quick question: What preservatives would be ideal for a soap like this? I've heard about a supposedly "natural" one called Neodefend. Would that be a good choice?
 
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"Neodefend. Would that be a good choice?..."

Not likely, although I haven't looked into it, but there are only a few preservatives that can tolerate the high pH of liquid soap. Suttocide A or Glydant Plus are two options. Although it's not on the official info, Liquid Germall Plus is also suitable for higher pH products. More: http://www.makingskincare.com/preservatives/

"...1/2 cup soap to 1cup oat/honey water and 1/2 cup xanthan gel..."

I cannot think of any preservative that will work well with that much food in your soap. That's like pouring a teaspoon of water on a bonfire with the expectation of putting it out -- it's really not going to work very well.

ETA: Honey can only be a preservative IF and ONLY if the honey is over 80% of the product -- in other words, it must be properly cured honey. Even honey in the hive can ferment if the bees don't take proper care of it before it is dry enough to be self preserving. If the bees have to be careful, so do we humans. If you add anything to honey to dilute it below the minimum safe sugar content, it ~will~ ferment and support bacterial growth.
 
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So my best bet is likely to just make a small batch to last a week before it ferments? Dr. Bronner's soap needs a pretty heavy level of dilution to not be really harsh on the skin and when you dilute it like that it just ends up more like water than soap. The formula i'm using at the moment makes a really nice and thick soap but is also gentle and soothing for skin. If a preservative isn't going to work I don't see another way around it till I can start making my own castille soap.
 
Congratulations on entering the wide and wonderful world of soap. That being said I would like to take this opportunity to say that a good chunk of the "soap" recipes you find on the internet are garbage. When I got started making my own soap from scratch I just went online and made a half dozen batches from random websites. Only when I learned to formulate my own recipes with a soap calculator did the quality of my soap increase. Just don't want to see someone throw money away on untried recipes.
 
So my best bet is likely to just make a small batch to last a week before it ferments? Dr. Bronner's soap needs a pretty heavy level of dilution to not be really harsh on the skin and when you dilute it like that it just ends up more like water than soap. The formula i'm using at the moment makes a really nice and thick soap but is also gentle and soothing for skin. If a preservative isn't going to work I don't see another way around it till I can start making my own castille soap.


I suggest you dive right in and make your own. If you estimate the amount of money you spend on products that are crap and you end up throwing away (your fermenting soap being one) then compare it to the money you'll spend on the ingredients to make your own, it's pretty similar. If you stick to the basics and don't go hog wild with buying bulk ingredients/expensive additives, etc., that is Once you get the hang of it (decide you really like it) then go hog wild. I started with a few containers of lard from Whole Foods and 10 lbs of lye I got online for about $15. (I was a "purist" at first. Only grass-fed locally raised pigs with names like "Buttercup" could produce lard for me. I got over that PDQ.)
 
I second Theresa's suggestion to start making your own. When you make your own, you can formulate it to your own skin type without having to invest a lot on a bunch of additions.

If you ask me, Dr. Bronner's is only fit for housework-type cleaning, as opposed to bodily cleaning. My brother bought a gallon bottle of Dr. Bronner's once for his family to use in the shower, but everyone hated it. It dried out their skin so bad. Instead of throwing it out, he found it made an excellent household cleanser for the toilet and tub. lol


IrishLass :)
 
I suggest you dive right in and make your own. If you estimate the amount of money you spend on products that are crap and you end up throwing away (your fermenting soap being one) then compare it to the money you'll spend on the ingredients to make your own, it's pretty similar. If you stick to the basics and don't go hog wild with buying bulk ingredients/expensive additives, etc., that is Once you get the hang of it (decide you really like it) then go hog wild. I started with a few containers of lard from Whole Foods and 10 lbs of lye I got online for about $15. (I was a "purist" at first. Only grass-fed locally raised pigs with names like "Buttercup" could produce lard for me. I got over that PDQ.)

Yes it's definitely something I'd like to do. However some concerns I have are that I have housemates, and fumes from lye may be of particular concern for one of them. The other one is that I need to find a source of Potassium Hydroxide that I am absolutely sure is 100% mercury free. The reason I even went with Bronners in the first place is they assured me on contact that their lye was not made in a mercury vat plant. I was actually thinking of just making my own from wood ash to be absolutely sure.

I had planned to start making my own soap in a few months mostly because I want to make soap with elderflower and my elder plants should be blooming around that time as well.

I second Theresa's suggestion to start making your own. When you make your own, you can formulate it to your own skin type without having to invest a lot on a bunch of additions.

If you ask me, Dr. Bronner's is only fit for housework-type cleaning, as opposed to bodily cleaning. My brother bought a gallon bottle of Dr. Bronner's once for his family to use in the shower, but everyone hated it. It dried out their skin so bad. Instead of throwing it out, he found it made an excellent household cleanser for the toilet and tub. lol


IrishLass :)

Yep it is a great cleaner. Whatever is left of this big gallon I bought will be used exclusively for cleaning.
 
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Yes it's definitely something I'd like to do. However some concerns I have are that I have housemates, and fumes from lye may be of particular concern for one of them. The other one is that I need to find a source of Potassium Hydroxide that I am absolutely sure is 100% mercury free. The reason I even went with Bronners in the first place is they assured me on contact that their lye was not made in a mercury vat plant. I was actually thinking of just making my own from wood ash to be absolutely sure.

I had planned to start making my own soap in a few months mostly because I want to make soap with elderflower and my elder plants should be blooming around that time as well.



Yep it is a great cleaner. Whatever is left of this big gallon I bought will be used exclusively for cleaning.


The lye fumes last for less than 5 minutes and only happen when KOH is mixed with the water at first.

Essential Depots COA says their KOH is produced in a non-mercury vat plant. There are actually 3 ways of producing KOH/NaOH and I believe that the mercury method is being mostly phased out as it contaminates all parts of the process (even the product). You can also contact the lye guy. Considering his lyes are sourced from the US, I doubt that they are made using the mercury process.

Essential Depot:
http://www.essentialdepot.com/msds/KOH_COA.jpg

http://www.essentialdepot.com/product/KOH-2.html

http://www.thelyeguy.com/store.php?crn=210
 
The lye fumes last for less than 5 minutes and only happen when KOH is mixed with the water at first.

Essential Depots COA says their KOH is produced in a non-mercury vat plant. There are actually 3 ways of producing KOH/NaOH and I believe that the mercury method is being mostly phased out as it contaminates all parts of the process (even the product). You can also contact the lye guy. Considering his lyes are sourced from the US, I doubt that they are made using the mercury process.

Essential Depot:
http://www.essentialdepot.com/msds/KOH_COA.jpg

http://www.essentialdepot.com/product/KOH-2.html

http://www.thelyeguy.com/store.php?crn=210

Excellent find thanks. I was never able to actually find someone selling KoH that explicitly stated it wasn't made in a mercury vat. You would think they would have totally phased it out, but Mercury being found in canned tomatoes and cage free egg shells recently definitely causes concern when mercury vat lye is being used on stuff that we ingest.

I'll probably look around for a cheap slow cooker and give the soap making a shot if the lye fumes aren't too bad.
 
Until you can make your own, why not see if you can buy someone's LS? Far better than using that Dr Bronners swill. And you can learn what a real LS is like. Can you tell we don't care for Dr B? :)
 
Until you can make your own, why not see if you can buy someone's LS? Far better than using that Dr Bronners swill. And you can learn what a real LS is like. Can you tell we don't care for Dr B? :)

Yeah no surprise there really. They advertise as being "castile soap" even though their stuff is made from mostly coconut oil. In fact there's even more palm kernel oil than olive in their soap.
 
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