Tips for Storing E-liquid
E-liquid is a food product and has a shelf life. It is also sensitive to heat. I’ve noticed that leaving e-liquid at room temperature and leaving the bottle open spoils the e-liquid flavor and intensity (or the so called throat hit). This makes your e-cigarette taste light and stale, which spoils the pleasure of e-cigarette smoking, so much that you might soon start craving for the real cigarette smoke.
Store E-liquid in Two Different Bottles
If the e-liquid you just purchased comes in a plastic bottle, transfer it to an amber glass bottle. The dark glass does a better job protecting your e-liquid. Store the glass bottle of e-liquid in a cool, dry place—your refrigerator is the best storage place.

Large Amber Bottle for Long-Term Storing of E-liquid next to 10ml Dropper Bottle
For refilling your cartridges, get a smaller bottle to carry around during the day. I find 10 ml amber glass dropper bottle very convenient—I keep the bottle, together with the batteries, atomizer, and cartridge in a box from ALTOIDS. At night leave the small bottle in your refrigerator to keep the e-liquid fresh.

E-cigarette Parts and 10ml Dropper Bottle Fit into ALTOIDS box
E-liquid in Cartridges
E-liquid is also available in sealed cartridges. Cartridges with e-liquid make it easier for you to try new flavors. But once you find your favorite e-liquid flavors, it doesn’t make sense to keep a reserve of sealed cartridges with e-liquid. Whether sealed or opened, the e-liquid stored in a cartridge won’t stay fresh for long. Refill the cartridges with the supply of fresh e-liquid you keep in your refrigerator.