Will Dr. Bronner stay good for the rest of my life?

November 3, 2008 11:18 AM

How long does liquid soap keep?

First, I'm specifically talking about Dr. Bronner's, in case that matters.

Second, I'm not asking "How long does it take to use it up"; rather, I'm asking "If I don't use it up, how long does it remain, uh, soap".

I'm running low, and was about to purchase another bottle, but noticed that by far the best deal by volume is for some absurd amount of soap that might just last me the rest of my life.

So, hopefully the answer to my question is "many many years; effectively forever". But if not, I'd like to know how long it stays good for, so that I can plan my purchase accordingly.

Thanks in advance.

posted by Flunkie to grab bag (19 comments total)

We've had a huge bottle of SoftSoap on the shelf for at least 3 years. Still good. We accidentally bought two because I forgotten I'd bought one on the last trip to Sam's club, so they took FOREVER to use.
posted by desjardins at 11:28 AM on November 3, 2008

Does it have one of those little pictures of a container with the lid coming off?.... oh never mind, look at this one here.
posted by le morte de bea arthur at 11:30 AM on November 3, 2008

Is it soap, or is it detergent?

Soap is made from animal fat or vegetable oil. Soap won't keep forever; the fat can become rancid, though it'll take a hell of a long time.

Detergent will last essentially forever.
posted by Class Goat at 11:46 AM on November 3, 2008

As far as I can tell, Dr. Bronners lasts forever. I know a family of four who buys it in two-gallon jugs, and they go through one per year, and it seems to work fine.
posted by Jon_Evil at 11:47 AM on November 3, 2008

Actually, just the other day I found a bottle of Dr. Bronner's that I had misplaced a few months ago and it was all crystalized at the top, but after a vigorous shaking it was perfectly fine, just a little cloudy. Still sudded and bubbled and smelled delicious. I felt clean, if that counts for anything.
posted by banannafish at 11:47 AM on November 3, 2008

le morte de bea arthur: Perhaps that answer was meant for a different question? If not, I don't understand.

xmutex: I'm not sure I understand your question ("How are we to know how you use soap"): I'm not asking "How long will it be until I run out"; I'm asking "If I don't use it, how long will it be before it goes bad".

Class Goat: Dr. Bronner's is soap, not detergent. They actually make a big deal out of this in their marketing. It's also "pure Castile", which apparently means that it's completely from vegetable fat, not animal fat. Any idea on how long "a hell of a long time" is?

Everybody: Thanks.
posted by Flunkie at 11:57 AM on November 3, 2008

I have had a jug of Dr. Bronner's almond-scented soap open for about 18 months now. Still works fine, still soap, nothing has separated. I keep it in my laundry room, so, not much light exposure, slightly damp as it is in the basement.
posted by kellyblah at 12:03 PM on November 3, 2008

Just make sure you don't buy one of the big Method brand refills from Target with the packaging that's supposed to decompose in the landfill. Because if you use the soap as slowly as I do you may find yourself with a big puddle of soap in your storage cabinet as the package begins to dissolve before you can finish using all the soap!
posted by MsMolly at 12:06 PM on November 3, 2008 [1 favorite has favorites]

Since this is a product-specific question, why not just write Dr. Bronner's and ask?
posted by Miko at 12:07 PM on November 3, 2008

What's the absurd amount? The biggest I can buy is 32 oz of Bronners, and we use that within three months. I put it into a smaller squeeze bottle and dilute it 50/50 so it goes further and doesn't plug the nozzle. You can use it to shampoo your hair, too.
posted by weapons-grade pandemonium at 12:08 PM on November 3, 2008

Flunkie, what I meant was that most liquid soap bottles that I've seen have a symbol which indicates the expected lifespan of the product after opening. I can't say how long it might last unopened though - that would really depend on environmental conditions... in a freezer it might last a few centuries. On a warm windowsill... not so long.
posted by le morte de bea arthur at 12:14 PM on November 3, 2008

I don't think that soap goes bad. Liquid soap is just solid soap with a lot of water added, and the only thing I could see happpening to your soap over an extended period -- even if you left the top off -- would be that the water would evaporate away, and then all that would mean is that you had...slightly less liquid soap.

The beauty of Dr. Bronners' is that it's made with a vegetable fat rather than an animal fat, so it doesn't really 'spoil', as such.
posted by EmpressCallipygos at 12:21 PM on November 3, 2008

Any idea on how long "a hell of a long time" is?

I would expect it to be about as stable as olive oil or peanut oil. They don't last forever, either, but they last "a hell of a long time".

Years, probably, if they're not stored in hot conditions.
posted by Class Goat at 12:33 PM on November 3, 2008

A friend gave me a travel-sized bottle of Dr. Bronner's in '91. It tastes horrible now, so no toothbrushing with it. But still cleans things nicely. Last used on some carpet stains about 2-3 months ago. That was maybe a 1/2 tsp in a gallon of warm water.

As far as I recall, the consistency etc hasn't changed. Nothing obvious, anyway.

Go for it.
posted by nakedcodemonkey at 12:47 PM on November 3, 2008

There is at least one common species of bacteria (Pseudomonas aeruginosa) that can live on and eat soap. My microbiology professor loved to talk about it, but googling for bacteria and soap tends to bring up unrelated info except for that one reference. Sorry I don't have a better citation.

I don't know if this bacteria could grow in Dr. Bronners, though. I know people who have been slowly working their way through 1L bottles of that stuff for years, and they seem to be doing just fine.

The distinction between vegetable and animal oil does not mean the vegetable oils in Dr. Bronner are less likely to go rancid, incidentally. I have no idea how the soap-making process affects things, but unsaturated fats in liquid oils actually go rancid more quickly than the saturated, solid fats from animal sources.
posted by vytae at 1:49 PM on November 3, 2008

EmpressCallipygos: Liquid soap is just solid soap with a lot of water added

Not true at all. Soap that is made with NaOH is solid, while soap made with KOH is liquid.

That only goes for Soap with a capitol 'S', though (which Dr. Bronner's is). Detergents are different.
posted by ArgentCorvid at 3:21 PM on November 3, 2008

The distinction between vegetable and animal oil does not mean the vegetable oils in Dr. Bronner are less likely to go rancid, incidentally. I have no idea how the soap-making process affects things, but unsaturated fats in liquid oils actually go rancid more quickly than the saturated, solid fats from animal sources.
posted by vytae An hour ago

Soap that is made with NaOH is solid, while soap made with KOH is liquid. That only goes for Soap with a capitol 'S', though (which Dr. Bronner's is). Detergents are different.
posted by ArgentCorvid at 3:21 PM on November 3

I stand corrected on both counts.
posted by EmpressCallipygos at 3:40 PM on November 3, 2008

At least two years (I buy Dr. Bronner's in 1-gallon jugs).
posted by magicbus at 4:07 PM on November 3, 2008

Anecdotally, we have a 12-oz bottle of Bronner's Peppermint Soap in our camping bag that has been there about 6 years. Last time I went camping I noticed that it had lost most of its pleasant peppermint fragrance, but still functioned just fine as soap.
posted by mmoncur at 4:55 AM on November 4, 2008