The shelf life of both commercial and homemade bubble juice can vary quite a bit with both conditions and the juice itself. The shelf-life of unopened commercial bubble juice shows quite a bit of variation among brands. DIY bubble juice can have good shelf-life, too, but there seems to be a fair amount of local variation -- more on this below.
Commercial bubble juice, if the container is unopened, should last a year or more without degradation, but some brands seem more prone than others to losing their effectiveness. I have had unopened bottles of bubble juice that were as good after 3 years on the shelf as they were when purchased.
It is important to distinguish between shelf-life of bubble juice stored in closed containers after brewing and the shelf-life of used juice.
Once you have opened a bottle of commercial bubble juice it may start degrading. The rate at which this happens can be quite variable. Even opened bubble juice containers sometimes stay viable for a year or more while others go bad within weeks.
Storing and using juice
It is best to store juice in a place free of temperature extremes.
Some homemade bubble juice will become less stable or cloudy after exposure to cold temperatures. In many cases, the juice will be effective when it returns to room temperature and any settled ingredients stirred back into the mix.
For best shelf-life, store your juice in clean, closed, airtight containers and pour juice into separate dipping containers or bottles. Once a bottle of bubble juice is opened, you should not pour used bubble juice back into it. Use a separate container (I use dipping containers with airtight lids) for used juice.
Used juice may remain viable for a while, or it may degrade quickly due to contaminants introduced by being open to the elements -- especially if your wicks or wands come in contact with the ground. There is a lot of variation in how long juice remains viable once exposed in this way.
Some used juice, such as guar mixes, are more prone to degradation once they have been used than others. My used PEO and guar juice often remains viable for weeks, but I have had used juice go bad in a handful of days. While that is rare for me, for some that is the norm.
Used Juice and Contamination
"Used juice" is subject to contamination. While many peope have good luck mixing juice in a bucket and then using the juice directly from that bucket without having it spoil, such use is risky. As soon as you expose your juice to the elements, it starts collecting microscopic contaminants (such as spores) and dust and pollen. This can lead to spoilage. Any juice can degrade in such conditions though some juice is subject to more rapid deterioration than others. It is best to mix your juice and store it in airtight containers. Pour juice into your dipping container as needed. If you have leftover juice, don't pour it back into the storage container -- it is bringing contaminants with it. Keep it in the dipping container. If you get another week or two out of it great. But you might not.
The issue of leftover or used juice degrading is different from the issue of well-stored juice spoiling in storage.
Degradation
There are two main sources of degradation for bubble juice: chemical and biological. Some bubble juice may degrade, even in sterile conditions, due to heat or oxidation. This seems generally not to be an issue with unused bottled bubble juice unless conditions become extreme or in situations where there has been an error in mixing. Some polymers (such as Guar Gum and HEC ) are prone to falling out of solution when the bubble juice is too concentrated. This rarely happens with properly hydrated fully-diluted mixes but can happen with concentrated mixes.
Biological degradation seems to be the primary enemy of bubble juice. There are microorganisms that feed on the polymers used in bubble juice. For most people, unused juice kept in closed containers, even guar-based juice (which seems more susceptible than other types of juice) remains at its original quality for six weeks or more -- sometimes much more. However, some people (see below) experience very limited shelf life.
Once the juice has been used, degradation is a bit unpredictable. Edward often uses large plastic mixing bowls with lids for dipping containers. He has reported that he had a guar-based mix that still worked great 8 weeks after it was first used. But, he has also reported cases of the same mix losing its viability in the used dipping container after a week or so.
Shorter shelf lives. For reasons that have not been determined, some (not all) people experience very poor shelf life (less than one week) for their mixes -- especially guar gum-based mixes. Others (such as myself) experience very good shelf life with the exact same recipes. Biological degradation, even for the same recipe, varies considerably from location to location because different locales (even different houses in the same area) have different bacteria, yeasts, and molds in the air. Some people report that when their guar-based juice loses its viability that it develops a terrible smell. Other people, in other locations, have mentioned that their unopened guar juice never seems to go bad (at least not within 8 weeks). Others mention that when their guar-juice goes bad, it does not develop a terrible smell but suddenly stops working.
Temperature
It has been observed that if homemade juice is allowed to get cold for an extended period of time (let's say below 60F -- though the exact temperature is not yet known), it may tend to "pearlize" (become a milky with an opalescent quality) and/or white precipitation may appear. This seems most likely to happen if the juice has been pH adjusted. Our recommendation is for juice to be stored at 60F or above. It is possible that 50F is safe, too, but we don't have enough data yet.
Preservatives
Commercial bubble juice uses preservatives to maintain long shelf-life. Some quality commercial bubble juice has an indefinite shelf-life; others do not. As bubble juice manufacturers are constantly tinkering, we won't mention specific brands and their shelf-life. It changes from year-to-year.
DIY bubble juice makers that need very long shelf lives have mentioned sodium benzoate, Glidant, chlorhexidine gluconate (or oral rinses in which it is the active ingredient), and mouthwash (one person has advocated Listerine) as effective preservatives, but we have not tested any of these at the wiki. In most cases, unused homemade bubble juice stored in clean, airtight containers has excellent shelf-life. If you experience shelf-life problems with well-stored unused bubble juice, please leave a comment or contact us. We are looking for people that have this problem so that we can learn more about what contributes to these issues.
In a posting on SBF, the Soap Bubble Fanciers Yahoo Group (RIP), Rick Findley mentions Suttocide A, Trisodium EDTA and Disodium EDTA as possible preservatives used at a maximum combined weight of 0.5% of the whole. See the thread here.
Sodium Benzoate. We have had a number of inquiries about sodium benzoate. Sodium benzoate is listed as primarily being useful for acidic environments. Most homemade bubble juice has a pH higher than the range in which sodium benzoate is considered effective.
(June 2017) We have no experience using preservatives and so cannot comment on the effectiveness of the treatment or whether it impacts the bubble juice.
Propyl Paraben. RogerH3 uses propyl paraben at 0.02% to 0.03%. It is reported to be effective against yeasts, molds, and bacteria, at these concentrations and at the pH range of bubble juice. (See for example https://www.ueno-fc.co.jp/english/pdf/PARABEN2013.pdf). I have not done any comparative tests to see what difference it makes.
Rick's Preservative Treatment - 2018
Rick Findley has found a combination of preservatives that gives his RAD recipe (or pretty much any bubble juice) excellent shelf-life. He recommends .3% Suttocide A partnered with .2% (disodium) EDTA. For 1 liter of bubble juice (which will weigh close to 1 kg),use 3 grams Suttocide A and 2 grams (disodium) EDTA. Suttocide A is effective in a wide range of pH's but is weak vs yeast whereas EDTA is effective against yeasts and is effective in our preferred pH ranges. See the discussion in the comments section for more details. With this treatment a batch of RAD repeatedly exposed to the elements in January 2018 was still viable in June 2018!
Where to find the ingredients. These ingredients can be found at shops and e-shops that sell ingredients for home soap, lotion and cosmetic making.
Homemade Juice
The shelf-life of unopened homemade bubble juice can be quite variable. The life seems related to local environmental variables as well as the detergent. Storage method and conditions make a huge difference. The primary enemy of bubble juice is biological degradation from airborne and ground borne contamination. Bubble juice that is left open to the elements will degrade very quickly compared to juice stored in closed airtight containers.
Edward says that he expects his fully-diluted mixes to last 6 weeks or more without degradation as long as they are unopened (though they have lasted much longer on the shelf) but prefers not to push the envelope--this is true for both baking powder and citric acid adjusted mixes. He has had mixes that were viable even after a year, but has had some go bad after a few months. Concentrates tend to have a much longer shelf life as long as they are not pH-adjusted. The high-pH of dishwashing liquid is intentional; it vastly increases the product shelf life. If you intend to store your mixes for very long times, it is best to wait to do any pH-lowering until use unless you use preservatives.
Guar gum-based recipes are the ones most frequently (but not exclusively) reported by others to degrade prematurely. Most people do not experience this, but some people do. This is probably due to local differences in either the guar gum brands or the local bacteria, yeasts and molds.
Edward has even had partially used dipping containers of homemade juice that were still viable after several months though such solutions can go bad after a week or two. Opened bottles of bubble juice made with either guar gum or PEO and using either baking powder or citric acid for pH adjustment sometimes last for months. Other bubblers do not have such good luck and the specific reasons for the variations is not well understood.
Impact of Detergent
The detergent used seems to be relevant to the shelf-life. Edward notes that while his unopened Dawn-based guar mixes have reliably had shelf-lives of 6 weeks or more, when Charmy is used instead of Dawn, the shelflife declines considerably. For this reason, he uses Charmy-based juice within days after mixing.
If you experience problems
If you have shelf life issues, this section covers some things that may be relevant. Some of these are only relevant to people with shelf-life issues.
Store juice in closed containers. If you do not typically store your juice in closed containers, store your freshly made juice in clean closed containers to see if that eliminates the probems. Juice left in open or loosely covered buckets and pots is prone to spoilage in a few days in some environments. We have encountered many people that complain about shelf-life who typically leave their bubble juice in open containers for extended periods of time. Edward recommends using bottles and jugs from detergent or commercial bottled water for storage. These containers start off clean
Use clean containers and vessels. Bubble juice should be made in clean vessels and put into airtight containers for storage.
Don't mix used and unused juice. Once juice has been exposed to the elements and used in a dipping container, it should not be poured back into a container of unused juice as the used juice will harbor contaminants. Make sure that your vessels have been well-cleaned. If you typically have shelf-life issues, you may want to use a disenfectant (such as a bleach/water mix) to disinfect your storage and mixing vessels before using them. Simply washing things with soap and water is not always sufficient if you are in an environment rich in the little beasties that eat polymers.
Use very hot water. This is not generally required. Edward does most of his mixing with room temperature and warm water (except for those polymers that require very hot water for hydration). Some people, however, regularly have shelf-life issues. Some of these people find that using very hot water improves the shelf-life of their mixes. If you regularly experience problems and are storing your juice in clean, airtight containers, using hot water for polymer mixing may help. You may want to mix your polymers using water at least 170 degrees F and make sure that the temperature stays over 150F for at least 5 minutes.
Guar gum and other natural polymers. Sometimes with natural products such as guar gum, the issue is spores that are in the packaging. For the intended use, this is not a problem. But you may need to try to kill them off. Usually hydrating with just-boiled water should be effective in reducing the occurrence of problems. Natural polymers are reputed to be more prone to biological degradation than synthetic polymers. It does seem that guar gum is more prone to shelf-life issues than the other common polymers. A simple water/guar gum solution (no detergent or other ingredients) will spoil in less than a week even when stored in the refrigerator.
Water issues. Sometimes, the problem are bacteria, yeast, or algae that is in the local water. Tap water is generally not a problem but in some locations there may be organisms that are not harmful but which feast on bubble juice polymers.
Checking for water issues. To make sure that the problem is not storage or your local water supply, mix your juice using disinfected utensils. Purchase a bottle of water (distilled, deionized or mineral). Use the water for your mix and pour the bubble juice into the bottle that contained the water. If that juice maintains viablilty longer than normally the next experiment is to purchase a bottle of water and discard the water using the bottle to store your next batch of bubble juice. If that works then the likely culprit has been your storage vessels.
More Observations
This guar and Dawn Ultra 3X juice had been stored for 8 months before it was used for the first time.
March 2018-Edward. On March 17, I used some guar-based juice that had been brewed in August 2017 (and left undisturbed since then in the gallon bottle it was mixed in). The juice contained Dawn Ultra 3x, guar gum, water and 5% citric acid solution to adjust the pH to 7.6. The water to detergent ratio was 22 to 1. While I didn't have a fresh made batch to compare it to (this was a "fun" session rather than a work session), my impression was that it performed just as well as a freshly made mix.
Jan. 2015-Edward. More evidence that bubble-juice shelf-life (for used bubble juice especially) seems to be highly variable and probably related to the local micro-organisms (yeasts, bacteria, etc.). In October 2014, I mixed up a number of batches of both PEO-based and guar-based bubble juice. Some were citric-acid pH adjusted and others baking powder-adjusted. Some bottles remained closed and unused while some of the juice had been poured into dipping containers with lids and partially used. These were all intended to be used at that time, but life intervened and I was unable to use much of the juice. Normally, I have low expectations for juice in dipping containers that have been used and allowed to sit for an extended period of time. Around January 1, 2015, I found myself with a chance to go to the park and make bubbles. I was surprised. Of the four containers with USED juice, three were fully viable and seemed to work as well as originally. One of those was especially surprising because the juice had turned milky. The one container that was a total failure had turned milky, too -- but one milky container worked! The pH of all the containers was within 0.1 of the original juice -- even the failed container. Adding more polymer failed to revive the dead juice. All of the juice that was bottled and unused worked great and had the expected pH. The unopened bottle of guar juice had no more sediment (baking powder) than a normal fresh mix and no sludge. THE LESSONS: Juice that has pearlized or gone milky may still be good -- or it may have failed. Juice may fail for reasons of age even if the pH remains stable.
Thommy mentions that in some cases (it probably depends on what the "bugs" are in one's environment leaving the container only loosely sealed may be beneficial. See his post here.