How long do chemicals last

[ShelleyDickison]

I am going into my LHBS today and realized all my chemicals are over a year and a half old. I was just going to pitch them and buy new but was wondering about the shelf life. There are no expiration dates on the bottle along with no storage info. I have stored all my chemicals in original containers in a large rubbermaid storage box, except for yeast. Any thought?

 

[reefman]

One of the experts will have to answer the shelf life issue, but I do know that keeping them in the fridge extends the life of most chemicals we use....especially yeast.

 

[Julie]

Not sure on all the chemicals but sorbate has a 6 month shelf life that can be extended to 1 year if refrigerated.

 

[GreginND]

It would help to know what all chemicals you are talking about. They all have different stabilities and shelf lives.

In general, chemicals should be stored dry and sealed, out of the light. Some are best in the fridge or freezer.

K-meta is very stable and should be fine stored at room temperature even for years. I've used K-meta before that was probably 20 years old with no problems.

Tannins, rock solid. Yeast nutrients and DAP stored dry and out of the light will also last years.

K-Sorbate is more sensitive. The general consensus is that it has a 6 month shelf life. But to be honest, if it is stored in the dark as a dry solid and not heated, it should last much longer than that. But it is useful to refresh it before it gets too old. I store mine sealed in the freezer. I expect it to be good for about two years. Solutions of sorbate will decompose much faster.

Yeast are good even past the expiration dates on the packages. I also store yeast in the freezer or refrigerator. I've used some yeast successfully up to two years past the expiration date when stored in the fridge. But yeast is relatively cheap and it's best to use it fresh if you have any doubts. It's not like all the yeasts die on that date. It slowly loses viability and there may be less viable yeast populations until you get to a point where there just aren't enough to get things going.

ML Bacteria are more sensitive. They can be stored in the freezer (dried) for 6 months. Some should still be viable past that if still sealed and dry.

Enzymes are also more sensitive and should be stored in the fridge. Depending on the enzyme, they can last a year or so.

In general, anything that is a dry solid or powder will last longer under the appropriate storage conditions than things in solution.

 

[Arne]

Great answer, Greg. Arne

 

[ShelleyDickison]

Thanks everyone.

 

[rob]

Greg, I would agree with 6 months on the Sorbates BUT how would you know how old it is?

 

[GreginND]

Good question. No good answer. The generally accepted 6 month shelf life most likely takes into account an average age of product being sold. But you never know. My experience is that most have a much longer viability lifetime than we think. My response is strictly about what I think as an organic chemist on how stable I think these chemicals are. And I am being conservative in my time frames. Again, when in doubt, replace with fresh.

 

[rob]

Greg, I have noticed some of the commercial wineries buy direct from Scott Labortorys, so do you think they might have a slight advantage over someone that buys it off a dusty shelve? Another point, what about someone that lives in a larger city and the sorbates gets rotated more often than a smaller town...lots to think about.

I my self have had issues in the past with refermenting, I really don't do anything different than what anyone else does, but have come to the conclusion that it has to be out dated sorbates. I have in the past seen members on this forum post that they are having bottle corks popping out and soon after that they disappear from the forum, have they failed at making wine or just stumbled on to some old sorbates????

 

[GreginND]

Yes, I would definitely buy sorbate from a place that does more volume. I would not trust a small LHBS that doesn't move the product quickly. I think the major on-line HBS's are ok.

If your sorbate is not bright white but shows yellowing or browning, do no use it.

 

[Runningwolf]

I feel the above posters are right on. Most chemicals stored properly are good for a year including sorbate if handled as Julie mentioned. The question is, how long has it been sitting on the store shelves or their backroom before it was brought out? Buying it online chances are you're getting a fresher product as they move it out quicker. Buying it from a place like Presque Isle Wine Cellars we supply wineries, winemakers and supply stores so we are buying it in very large quantities and turning the product over quickly.

With that said, your local home winemaking store may be purchasing small amounts weekly/monthly and stocking very fresh product also. Just beware of dusty products not moving on their shelves, or product on display with the sun beating down on them.