How do Dr Bronner's & Vermont Soap preserve their liquid castile soaps?

[asb]

Hi,

I've been reading up quite a bit about the difference between antioxidants and preservatives, and why a good broad-spectrum preservative is necessary to prevent microbial activity in liquid castile soap. However, I see brands such as Dr. Bronner's and Vermon Soap (they have a 3 year shelf life on all their products) selling their products without the addition of any preservatives, but only antioxidants such as Tocopherol (Vit E) and rosemary extracts.

How is it that their products stay uncontaminated by microbial activity (since antioxidants can only slow down the rancidity of the oils used in the saponification process)? I want to start using and making liquid castile soap for my family, but want to make sure that the major brands selling these products out there are also being safe when it comes to microbes.

This forum has taught me a lot about liquid soaps, and I was wondering if anyone might be able to shed more light on this issue.

Thanks!!

 

[artemis]

Googling "Vermont soap liquid ingredients," it looks like they are using rosemary extract as a preservative. Googling the same for Dr Bronner's, though, I don't see anything listed. Weird.

 

[Saponista]

I read somewhere that aything with a high enough pH even when water based could be used without a preservative. But I can't remember how high thet pH was..... Doesn't the rosemary extract just stop oil from going rancid rather than preserve?

 

[artemis]

Doesn't the rosemary extract just stop oil from going rancid rather than preserve?

I think so, but that's what the ingredients list said: "rosemary extract (as a preservative)."

 

[asb]

Thanks, artemis and Saponista! I found this link where Vermont soap claims that its rosemary extract acts as the preservative: "Rosemary extract is our anti-oxidant natural preservative".

https://vermontsoap.com/rosemary-essential-oil-products/

I think it's probably down to the high pH of the soap, and good manufacturing practices that Dr. Bronner's and Vermont Soap don't have to actually use a broad spectrum preservative...interesting...

 

[earlene]

I don't know that I agree with the first part of this statement from the soap queen and she doesn't include references to back up her claim:

"Liquid soap does not need a preservative either but it doesn’t hurt to add a little just to be extra careful." (link)

Look at this thread for an SMF member's experience with her LS after one year without a preservative: https://www.soapmakingforum.com/threads/i-take-it-all-back.42659/

There are a group of organisms that grow in alkaline environments, including Vibrio cholerae, a deadly organism. (CDC link)

Also of interest from Lumen Learning (link), which shows that some organisms evolve to tolerate alkaline environments, suggesting that over time, there will be more:

"At the other end of the spectrum are alkaliphiles, microorganisms that grow best at pH between 8.0 and 10.5. Vibrio cholerae, the pathogenic agent of cholera, grows best at the slightly basic pH of 8.0; it can survive pH values of 11.0 but is inactivated by the acid of the stomach. When it comes to survival at high pH, the bright pink archaean Natronobacterium, found in the soda lakes of the African Rift Valley, may hold the record at a pH of 10.5 (Figure 3). Extreme alkaliphiles have adapted to their harsh environment through evolutionary modification of lipid and protein structure and compensatory mechanisms to maintain the proton motive force in an alkaline environment. For example, the alkaliphile Bacillus firmus derives the energy for transport reactions and motility from a Na+ ion gradient rather than a proton motive force. Many enzymes from alkaliphiles have a higher isoelectric point, due to an increase in the number of basic amino acids, than homologous enzymes from neutrophiles.:

Just as an example of evolution of micro-organisms, consider the strains of flu that keep popping up every few years. They evolve in order to survive the environments they are exposed to, thus new vaccines have to be developed periodically.

I think it's probably down to the high pH of the soap, and good manufacturing practices that Dr. Bronner's and Vermont Soap don't have to actually use a broad spectrum preservative...interesting...

So I disagree with the idea that GMP has anything to do with it, nor does the alkaline environment. I believe they are playing with fire, because they just do not know what the consumer is going to do with that soap, how long before it will be used, etc.

Some folks ALWAYS add more water to liquid products to extend use. They don't know adding tap water or even spring water or even sea water, might compromise the product. I don't know if you know anyone like that, but I know a few who do this regularly and have done their whole lives, as did their parents.

 

[OldHippie]

I found this link where Vermont soap claims that its rosemary extract acts as the preservative: "Rosemary extract is our anti-oxidant natural preservative".
https://vermontsoap.com/rosemary-essential-oil-products/

I think that this is fair for a product description. The average person has a vague idea what a "preservative" is, which in common usage is a broad class that would include "antioxidants", which the average person may not understand.

However, for the benefit of consumers, the Codex Alimentarius Commission has prepared the International Numbering System for Food Additives (INS), which provides an agreed international numerical system for identifying
food additives. Under their "Functional Class of Food Additives", They list
preservatives and antioxidants as separate class titles.

This is a useful resource for INS info:
https://www.cfs.gov.hk/english/whatsnew/whatsnew_fstr/files/ins_list_num_order.pdf

 

[lenarenee]

I didn't really read this thoroughly but want to add that a preservative can piggy back on another ingredients such as a fragrance, and there doesn't have to belisted on the label.

 

[OldHippie]

I didn't really read this thoroughly...

Shame on you...

... a preservative can piggy back on another ingredients such as a fragrance, and there doesn't have to be listed on the label.

Those vendors are not likely to add more than it takes to preserve their product, and by the time you add it the activity will have diminished, but most importantly, it will get diluted to the point of oblivion anyway. Good point though

 

[Zany_in_CO]

... a good broad-spectrum preservative is necessary to prevent microbial activity in liquid castile soap.

Necessary? Could you share your source please?

...I see brands such as Dr. Bronner's and Vermon Soap (they have a 3 year shelf life on all their products) selling their products without the addition of any preservatives,

Good question, asb, and well thought out. FWIW, here's my answer:
To quote Catherine Failor, "Fully saponified soap requires no preservative."
Dr. Bonner's and Vermont Soap have been around a very long time and I'm sure if their products spoiled at any point in time they would have added a preservative. A quick google reveals there are many others as well. Here's just a few.

Vermont Soap - Foaming Hand Soap
http://www.vermontsoap.com/foamer.shtml
Ingredients: Saponified organic olive, coconut and jojoba oils, vegetable glycerin, organic aloe vera and rosemary extract.
NOTE: Contains no preservative but does use antioxidant ROE (Rosemary Oleoresin Extract) -- an excellent alternative to using preservatives.

Dr. Bronner's http://www.drbronner.com/DBMS/LS.htm
Pure Castile Liquid Soap - Baby Unscented 32oz.
https://tinyurl.com/All-Natural-Castile-Liquid-Soa
Ingredients: Water, Saponified Organic Coconut*, Organic Palm* and Organic Olive* Oils (w/Retained Glycerin), Organic Hemp Oil, Organic Jojoba Oil, Essential Oils**, Citric Acid, Vitamin E
NOTE: Contains no preservative but does use antioxidant Vitamin E -- an excellent alternative to using preservatives. The citric acid may contain preservative qualities as well. Dunno.

Dr. Woods Pure Almond Castile Soap, 32 Ounce
Ingredients Purified Water (Aqua), Saponified Coconut, Hemp and Olive Oils (with retained Glycerin), Tocopherol (Vitamin E), Natural Almond Fragrance, Sea Salt, Citric Acid, Rosemary (Rosemarinus Officinalis) Extract

Oregon Soap Company - Liquid Castile Soap
Ingredients: cocos nucifera (coconut) oil,* olea europaea (olive) fruit oil,* helianthus annuus (sunflower) seed oil,* potassium hydroxide, aloe barbadensis leaf juice,* citric acid, butyrospermum parkii (shea butter),* rosmarinus officinalis (rosemary) flower extract. *organic ingredient

Carolina Castile Soap
Ingredients Organic Coconut Oil, Organic Olive Oil, Kukui Nut Oil, Organic Cocoa Butter, Citric Acid, Potassium Hydroxide (none remains after saponification), Water, Tocopherol (Vitamin E)

I've been making LS for personal use since 2004. This whole thing about LS "requiring" a preservative is a fairly recent phenomenon. If it's "required" why isn't there a preservative specifically formulated for liquid soap? Preservatives are made for lotions & potions and such -- and each one is designed to serve a specific type of product, liquid soap excluded because it's alkaline, vs acidic.

I don't use a preservative and I've never had a problem. Quite the opposite. My liquid soaps just keep getting better over time. Some soapers say, "I make LS for personal use, but if I were to sell, I would add a preservative." I do sell, but I don't add preservative... I have made LS for two different wholesale customers -- one a Dr. B type LS and the other a Goat Milk LS. I've also made 100% almond oil shampoo for a customer.

That being said, it's totally up to you whether or not you include a preservative in your LS. Many LS-ers do include it -- on the basis of "rather safe than sorry".

HAPPY SOAPING!

 

[SoaperForLife]

Maybe someone should send a freshly made liquid soap sample off to Sagescript for testing. Hold back another sample from the same batch and send it to them after 6 months (more or less) to see if counts have changed.

 

[Zany_in_CO]

Lotion Crafter sells an inexpensive DIY Microbial Test Kit for Cosmetics here:

http://www.lotioncrafter.com/microbial-test-kit-4_pack-lotioncrafter.html

 

[Zany_in_CO]

Maybe someone should send a freshly made liquid soap sample off to Sagescript for testing. Hold back another sample from the same batch and send it to them after 6 months (more or less) to see if counts have changed.

There's a thought! I wouldn't do that, even tho Microbiologist Cindy Jones, PhD of Sagescript is just North of Denver, about a 2-hour drive from me. With over 10 years experience, I feel confident about my liquid soaps being perfectly safe for personal use, for gifting, and for selling.

BUT...
Anyone who is seriously concerned about whether or not their LS needs a preservative should have it challenge-tested for their own peace of mind. I'm not sure Cindy is still doing challenge testing of lotions and potions or not, but you can contact her here:

https://sagescript.com/education/

She used to charge $30 per test, which is reasonable considering most facilities charge $300 (the last I heard) and that is per batch (and each subsequent batch every time you manufacture it). I've had a couple of discussions with Cindy over the years and she is both knowledgeable and very helpful. Basically, she said preservatives are an absolute must for leave-on cosmetic products like lotion but she couldn't say for certain whether or not it was necessary for liquid soap.

 

[SoaperForLife]

Cindy doesn't do challenge testing. That is way more expensive!!!! She does plate counts...
Plate counts will tell you whether your product is contaminated with bacteria/fungus at the time of testing. It is more a test of your GMP than of your preservative efficacy. Aerobic plate count (APC) – enumeration of bacteria present in a sample
Fungal/yeast count (F/YC) – enumeration of fungi (mold) or yeast present in a sample
Challenge Testing or Preservative Efficacy Testing This is the most rigorous test to determine whether your preservative is working. It involves introducing known bacteria (E. Coli, Pseudomonas, and Staph) and Fungi (Aspergillus, Candida) into your product. Plate counts are done at various times over a months period afterward. If the preservative is working, counts will decrease within 2 weeks and not increase again after that. We no longer offer this test and recommend Cosmetic Test Labs at MicroChemLabs.

Testing your GMP is a good idea for anyone making products other than soap. It will tell you if your efforts to sanitize your equipment and work area as well as yourself are working.

 

[Zany_in_CO]

Good to know! ILST (I learned something today!)

 

[Veggiebin]

I have made a liquid olive oil soap and had it create a film of something on the bottom of the jar over time - a long time, like a year. Not sure what it was exactly, but I stopped giving it away or selling it for that reason. Haven’t found that with my coconut oil soap, but I tend to leave it in paste form and make it up as I use it. I’ve wanted to do plates myself, so maybe I will send it out - mainly out of curiosity, but it would be good to know if I could sell it. But the biochemist in me wants to make an incubator so I can test whenever I want to ))

 

[bodhi]

They sell so much of it in such a high volume that they probably don't add any preservatives to it.

 

[Zany_in_CO]

They sell so much of it in such a high volume that they probably don't add any preservatives to it.

Um, did you miss the part on their site where it says it has a shelf-life of 3 years? Truly, the reason they don't use preservative is because it isn't necessary. I don't use preservative and I have one bottle of my Flaxseed & Rosin Shampoo that made it to 4 years!

 

[SoaperForLife]

Not trying to beat anyone up here but just because a product appears fine doesn't mean that it is.... you could have high plate counts and not even know it. I was googling on the reason why older liquid soap separates (the sludge at the bottom of the bottle) that veggiebin was referring to and stumbled across this:
"Preservatives - there is a lot of discussion regarding the need to preserve liquid soap. Many people will not use preservatives and many will always use preservatives. Liquid soap naturally has a pH of 9 - 10. Oftentimes the pH will be lower than that due to intentional lowering of the pH or by the additives used during/after dilution. Most bacteria will not grow in a high pH product (over 10) but the lower the pH, the higher chance that the environment will be conducive to bacterial growth. Mold and yeast will grow at higher pH levels than bacteria. Also, many additives create an environment more conducive to bacterial growth (proteins and water soluble extracts). I have been advised that it is a good idea to preserve your soap if the pH is lower than 10. The problem then becomes which preservative to use for liquid soap. Many preservatives have pH restrictions that do not go high enough for our alkaline soap products." http://alaiynab.blogspot.com/2013/09/adventures-in-liquid-soapmaking-hints.html

I made liquid soap back when preservatives weren't even hinted about and sold it without any. I have also made it with preservatives when everyone started using them. Maybe part of the reason for using them now is because people do seem to tinker around with the PH more than they used to... There is a reason why liquid soap separates overtime, it's just been too long since I've run across it...

 

[OldHippie]

"The problem then becomes which preservative to use for liquid soap. Many preservatives have pH restrictions that do not go high enough for our alkaline soap products."

I'd never heard this one before. Does anyone have any more information about this issue?