How long?

Depends on the brand and juice. Little to no sweeteners and color the longer the life span generally. One exception to that is plain custards. 2-5 years if stored in a cool dark place.
DIY is you best bet if you're in a country with restrictions or upcoming restrictions.

 

Stored in a cool place away from sunlight, much more than 2-years. Stored in a freezer, maybe indefinite.
Others may disagree. But, two years properly stored is certainly too conservative.
Some flavors probably react differently, especially under less than ideal conditions. But, unflavored nic liquid, properly stored, seems to be indestructible.

 

Unflavored in the freezer, yep most likely indefinite.

Flavored at room temperature: My experience parallels Letitia's: It depends on the flavorings and sweetners used. I've had vendor juices that got nasty (dark, and an off smell) in less than a year. I've had others that still look and smell fine after 5+ (although I'm not sure why I keep those still; I haven't touched 'em in years and am unlikely to ever do so again).

 

For science! How else would we be able to answer these types of questions?

 

Every wonder what vaping 6-year-old liquid is like?

 

I was just going to post about the same thread smacuser mentioned. Unless it gets hot it should be fine. No need to freeze but fridge should make it last a very long time. Go for it!

 

The jury is still out

 

I agree with the suggestion of DIY... if you are trying to store a lifetime of flavored liquid #1 it will not be good for a lifetime #2 even if it did last, you would probably need to rent a storage space. #3 it would cost a fortune.

You're much better off with DIY. You can store 100mg nic in the freezer indefinitely, your liquid will cost pennies not $.$$ to $$.$$, and it will take up far less space as you would only buy the PG/VG/Flavoring as needed.

 

I keep premixed liquids in the fridge and they've held up well for 3+ years so far. Unflavored/nic concentrate stays in the freezer.

If I had a premix that I really wanted for the long run I'd keep it in the freezer, in glass bottles with polycone caps. Plastic bottles and rubber droppers will allow oxidation/degradation more than I'd want over extended time.

 

The first ever liquid that I used that I actually enjoyed and that got me off cigarettes is still okay I've been vaping for 3 years and the juice was not new when I purchased it as in like newly made it was at a gas station it doesn't have a born on date but it does have an expiry date in 2016. It's a very sweet grape flavored liquid that's almost an amber color and I remember that it was almost an amber color back then and it's 12 milligrams per milliliter. So if anything is going to taste bad it would probably be that and so far it hasn't. Now I also have a juice that is from like 2018 in December and you couldn't pay me to vape it not sure if it's cuz it's gone bad it doesn't taste or smell rancid but I just don't like the flavor. I'm not entirely certain if I ever did. it's a very sweet grape flavored liquid that's almost an amber color and I remember that it was almost an amber color back then and it's 12 milligram per milliliter. so if anything is going to taste bad it would probably be that and so far it hasn't. Now I also have a tooth that is from like 2018 and December and you couldn't pay me to vape it not sure if it's cuz it's gone bad it doesn't taste or smell ran said but I just don't like the flavor. I'm not entirely certain if I ever did. so the jury is out lol