sugar scrub stability

[jessicammorton]

I made a sugar scrub and thought it was totally shelf-stable w/o preservatives, but then I noticed a "milky haze" in it after a week or so, and then that went away (or settled out) after 2-3 more weeks. I use brown sugar and ground almonds as the exfoliants, and the rest of the ingredients are plant oils, essential oils, and raw wildflower honey. There is a thick layer of oil that coats the top of the sugar and nuts, and I don't add any water (I heard honey was ok, as it has natural antibacterial properties). I thought maybe the milky haze was maybe coming from suspended solids in the nuts (almond milk?).

Any food science geeks - like me - out there who can advise? Does a formula like this need perservatives? IMHO, I thought the water activity was way way too low for anything to grow. It smells great and works fine, without any skin reaction.

 

[Deda]

are you using it in a damp environment? are scooping it out with moist hands?

 

[carebear]

I made a sugar scrub and thought it was totally shelf-stable w/o preservatives, but then I noticed a "milky haze" in it after a week or so, and then that went away (or settled out) after 2-3 more weeks. I use brown sugar and ground almonds as the exfoliants, and the rest of the ingredients are plant oils, essential oils, and raw wildflower honey. There is a thick layer of oil that coats the top of the sugar and nuts, and I don't add any water (I heard honey was ok, as it has natural antibacterial properties). I thought maybe the milky haze was maybe coming from suspended solids in the nuts (almond milk?).

Any food science geeks - like me - out there who can advise? Does a formula like this need preservatives? IMHO, I thought the water activity was way way too low for anything to grow. It smells great and works fine, without any skin reaction.

As a food science geek (seriously, it's my degree ), yes you need a preservative.

The milky haze probably isn't bacterial or fungal if the product had never been used, but still - you need a preservative because it is entirely likely that water WILL be introduced and that there will be localized areas of higher water activity. If it has been used - and contaminated with water - well then all bets are off and the milky haze could be anything.

Read on...

Water can be introduced while in-use, from wet hands and shower splashing and the like. Also due to the hygroscopic nature of your scrub, condensation can form in the high humidity environment of a steamy bathroom or shower.

Honey's antibacterial properties won't do **** in a mixed system, by the way. Honey on it's own is pretty well preserved by these mystical powers and by the high concentration of sugars, but it won't preserve other things.

 

[jessicammorton]

No, the product got the milky haze before being used and after being packaged in sanitized jars. The amount of "growth" was a lot, considering the situation, so I might chalk it up to the almonds getting milky in the oils. I can keep the scrub in the fridge after opening, but I want to be able to sell this product w/o causing too much inconvenience for the customer. What do you recommend to use as a preservative? I am going the all-natural route and would like to steer away from parabens. It's quite confusing and it seems like everyone has an opinion...what's yours? Thanks

 

[bodybym]

I like optiphen because it is paraben free - and it works in all applications so I only have to have 1 preservative.

 

[carebear]

optiphen is an excellent choice. http://www.snowdriftfarm.com/optiphen.html

it's unlikely you'll find a "natural" preservative that is effective without serious negatives like absurd cost, stinky odor, and narrow range of efficacy. if you do find one, please let us know - crafters the world 'round would love to hear of it.

 

[carebear]

Oh, and keeping it in the fridge - even for yourself - is no guarantee that things won't grow.

And beyond inconveniencing them, customers cannot be trusted to follow directions.

 

[Tabitha]

I want to be able to sell this product w/o causing too much inconvenience for the customer.

I can not think of anything more inconvenient that finding the scrub I just bought is molded. Many people who are trying to go the all natural route dislike preservatives, but mold/bacteria is much worse, IMHO.

 

[jessicammorton]

Oh, and keeping it in the fridge - even for yourself - is no guarantee that things won't grow.

And beyond inconveniencing them, customers cannot be trusted to follow directions.

yes - they are there, but they'll just grow slower!

 

[madpiano]

I like to make my scrubs without preservative, but that does mean I have to make a compromise. There is no way I would put foodie items (like almonds or seeds) into it and I have now gone off "normal" scrubs and do single use ones instead. It's just safer that way, if I want to keep the preservative out.

Theoretically, the small amount of water introduced to it by wet hands shouldn't be an issue, but I cannot guarantee that a customer doesn't leave the scrub in the shower and drips into it, and I have had tubs fall into the bath before. Just don't want my customers to have mouldy products from me.

 

[jessicammorton]

Hmmm...what if the scrub is packaged in a squeeze tube (like sunscreens), which would prevent contamination from air, water, and hands? Could I then use a natural complex of preservatives (I am thinking GSE, rosemary extract, sorbic acid, and perhaps phenoxyethanol) and have a 6 mo or more shelf life? Only way to know is to try, right?

 

[Deda]

challenge testing, apc's and all the lab fees are quite expensive.
how will you know if your natural preservatives will hold up?

 

[carebear]

No a squeeze tube is not going to protect it enough.
And that cocktail isn't going to do it - GSE is an antioxidant and despite some flawed research out there it's not a preservative. Sorbic Acid has a limited range of efficacy and seems to be good to preserve a product from the micro-organisms that are introduced during manufacture (from relatively clean products in a clean environment) but is not effective against contaimination after the fact if there is much at all. Phenoxyethanol is a sensitizer and an irritatnt and I'd personally stay away from it.

Here is just some of the info on Sorbic Acid - tho I think potassium sorbate is probably a better option and still not enough.

http://www.snowdriftfarm.com/lotionmaking101_p3.html

 

[jessicammorton]

Thanks for the info Carebear...so, in lieu of all those natural preservatives i mentioned, what is a sure-fire choice/choices that I can trust using in most applications without skin irritation, photosensitization, carcinogenic effects? This is a new area to me and I appreciate your opinions.

Don't you still need to challenge test and micro test products preserved with the synthetics, too? What are other cottage skin care businesses doing? Maybe I just need to suck it up and stick with shampoo bars, solid lotions, and dry scrubs if all-natural is the way I intend to go

 

[carebear]

The choice of preservatives will depend on the exact system being made - optiphen is a good option in many cases and there are others.

Anyone who makes a product with water (either in the formulation or expected to have it introduced) needs to have them tested. This said, it's "challenging" to test a scrub as it's hard to say how much water will be introduced by a consumer. I don't sell scrubs or hydrous products as I will not deal with that.

 

[jessicammorton]

Thanks - I think I will order some Optiphen Plus and try it in concert with other natural preservatives. I was looking at the ingredient lists for Burt's Bees and saw that they use phenoxyethanol, which must mean I can use the optiphen and still say my product is natural (although "natural" could mean just about anything these days). And maybe switch to the squeeze tube packaging...although the instructions for my jar product say to use a clean spoon, you're right: consumers can't be trusted to follow that. So much to learn!

 

[carebear]

you can use ANYTHING and call it natural.

hell, what is petroleum if not natural? it's brought up from the ground, and even better it's derived from the carcasses of rotting dinos?

But anyway, I think that most phenoxyethanol around today is compounded (made, synthetic, whatever) as opposed to somehow derived from nature. It's quite controversial as you will see if you search on "is phenoxyethanol natural" or "phenoxyethanol toxic" or the like.

 

[jessicammorton]

OK, I think I convinced myself I don't want to go the phenoxyethanol route...anyone out there using just essential oils, GSE, rosemary extract, sodium benzoate, citric acid, and other natural extracts (aspen bark, willow bark, etc) for a preservative system? I am not looking for the 2 year shelf life of commercial products, 6-12 months is fine.

 

[agriffin]

OK, I think I convinced myself I don't want to go the phenoxyethanol route...anyone out there using just essential oils, GSE, rosemary extract, sodium benzoate, citric acid, and other natural extracts (aspen bark, willow bark, etc) for a preservative system? I am not looking for the 2 year shelf life of commercial products, 6-12 months is fine.

I don't think you're going to get the answer you are wanting. "Natural preservatives" just don't exist. I think your best bet is optiphen or something similar.

If you choose to go the "natural" way with extracts, etc...you'll just have to do and see. But it is not something that will "definately" work. Too iffy for me, especially if I am selling my product.

 

[jessicammorton]

Well, maybe I can use optiphen at a low level and supplement with other natural preservatives until I learn more about preservation systems...my main concern with optiphen is that phenoxyethanol is considered a skin irritant.

I made some creams 3 months ago that I was just trialing with, and did not use anything to preserve except a little GSE and essential oils (I didn't even bother to sterilize my jars that time). I use those creams every day, and several of my friends do too, and they are always stored in the bathroom cupboard...no sign of problem yet, no mold and no separation in either of them and they still smell great too. So the preservatives maybe don't need to be too high, anyway.