Sunlight, heat and air (oxygen), are the enemies when it comes to long term storage of concentrated flavorings, liquid nicotine and mixed juice. Flavorings and mixed juice can go bad after a year or two if stored at room temperature however some flavors hold up better than others. The warmer the environment the quicker they deteriorate.
A few tips;
For "long term" storage (>1 year), use only airtight glass containers, oxygen can't permeate through glass.
Colored glass helps blocks UV, clear glass does not so use amber or cobalt blue bottles when possible.
Storing liquids in a dark place -prevents- UV deterioration.
Cold storage prolongs the life of liquids, the cooler the better but some flavors aren't suited for cold storage.
Stored in airtight glass containers and kept in a freezer, liquid nic will remain viable for many, many years.
Less head space = less air (oxygen), sealed inside your container, store "full" when possible.
Stored in a freezer the viscosity of PG and VG will increase (become thicker), but they will not freeze solid.
