Shelf life of chemicals

[TNFISHRMAN]

What are some of the chemicals that have a limited shelf life?? Also, What are the shelf life of those chemicals? Thanks, Lynn

 

[Fruit n Nut]

Over here in the UK every item should have a best before date stamped on the Label surely its the same over the Pond ?


In generall I usually find that mysupplies never get anywhere near the suggested BBD.


Providing any substances (Legal ones) are kept within a cool temp and adequately stored you shouldn't have much to worry about, my main concerns are keeping the containers,tubs and sachets out of harms way from the little wandering fingers.

 

[Angell Wine]

Just Make more wine and the chemicals will never go out of date.

 

[masta]

I just checked my wine making chemistry set and didn't find any expiration dates. I will work with George and see if we can get this information for you.

 

[TNFISHRMAN]

Thanks, Masta


I knew I had heard that there were some with limited shelf life. I just wasn't sure what they were. I remember being told that pectic enzyme had a limited shelf life, but wasn't told what it was.

 

[Joseph1]

I believe that the manufacturers place either a production date or a best buy date on the chemicals they produce. This information is probably lost at the distributor. The distributor receives a 50lb pail of potassium metabisulfite that has a production date. The distributor repackages into smaller packages for the home winemaker and the production date is lost.<?amespace prefix = o ns = "urnchemas-microsoft-comfficeffice" />

Shelf life is not only dependent on the production date. The process of repackaging and the package itself can affect it. For an idea of the shelf life of some of the chemicals used, check this site:

http://www.lamotte.com/pages/common/pages/reaglist.html

 

[DrtDoctor]

Newbie question.

Can you save left over, mixed, easy clean in a clean sealed container or isn't it worth it. If you can save it, for how long??

DrtDoctor

Started my first batch 5 days ago!!!

Edited by: DrtDoctor

 

[geocorn]

Most of the chemicals used in home wine making will keep for several years if stored in an airtight container in a moderate temperature.


All of the cleansers sold to home wine makers will only last for 4-5 hours. They are either oxygen or chlorine based and as such won't last long. The sulfite sanitizers on the other hand will last for 2-3 months after mixed with water when stored in an airtight container.

 

[Hal Maulden]

From a Chemist perspective:


George is correct that most chemicals, when stored correctly will last for years. That does not mean that they will retain their original potentcy. As an example: I used Iodide to titrate for SO2 levels. This chemical should be standardized at least once per month, if not weekly. Sodium Hydroxide, used in your acid titration kit, will absorb water and CO2 lowering the normality factor. I think one of the best advices I could give is to buy small volumes. I know, it's more expensive. But only buy what you will use in that wine making season. It ends up being cheaper than buying alot of chemicals to continuous do standardizations.





Hal

 

[smurfe]

Hal offers good advice, In a similar manner, I buy my chemicals for my pool this way, particularly my test materials. Now most pool chemicals are kept in a pool house which in not a controlled climate like in your home so there is a quicker degree of degradation than if kept in the home.


Chemicals and test stripsWILL degrade with age and can give inaccurate results. I experimented with a fresh test kitlast summer with the leftovers from the previous years kit and the year before thats kit leftovers. The test results were nowhere near the same with each age of test strip! I compared my fresh test kit with a neighbors fresh test kit and got identical readings. If I would of used the materials from the previous season.


I would of threw the chemistry of my pool way off. I would think that it would be even easier to mess up a good wine than my pool with inaccurate test results by the factor of volume alone. I for one am going to follow this practice and make my OWN expiration date on my chemicals and replace as needed.


I do wonder though how retailers know how old the chemicals are? How do I know it hasn't sat on a shelf at a retailers for 5 years and was made 2 years before that? I know some materials it won't matter but I am sure some will.


Smurfe

 

[geocorn]

You raise a very valid question regarding what retailers do. I don't know about others, but we constantly rotate our stock to make sure that the oldest items are in the front. It is a pain, but worth the effort.


We started this with the kits and yeast, then expanded the practice to the chemicals.


The one chemical that is a concern to me is Sodium Hydroxide. From what I read, it is fairly unstable and may go bad in 6 months. Not sure there is much anyone can do about that. I will say that I have had better luck with the 1/5 normal solution than the 1/10 normal.