If you want to keep your e-liquids for a long period of time, simply keeping them out in the open won’t work. The liquids will lose their flavor over time and become bland, and you’ll have to spend the money to buy new flavors. However, you can keep that from happening by storing your e-liquids in cool and dark places. Why would this work? To understand the reasoning behind storing e-liquids in cool, dark places we should first look at how e-liquids are made and how their flavors are kept in the liquid.
Flavors are made of the molecules that create flavors. Different flavor molecules are different sizes and weights, which means they act differently under the same circumstances. Larger and heavier molecules are not volatile, meaning they won't escape the bottle upon opening to the air. On the flip side, the lighter and smaller molecules of certain flavors will easily escape when the bottle is opened. Tendency to escape in gas form is known as volatility. What types of flavors have the different properties? The most common ones that show tendencies of large and non-volatile molecules are vanilla and caramel based flavors. These flavors will not lose flavor over time even if opened quite a bit. Fruity flavors and sweet flavors will tend to be more volatile.
Molecule volatility is effected by certain environmental conditions. The two primary conditions that change how molecules act are light and heat. Exposure to light will excite molecules, making them significantly more volatile. This also applies to heat - think of water over heat. The boiling reaction that occurs is due to the heat exciting the water molecules. Though you probably aren’t boiling your e-liquids (we certainly hope you aren’t), even small modulations in heat can create changes in volatility. Therefore, exposing frequently opened e-liquids to light and heat is probably a bad idea if you want to retain flavors. Keeping those e-liquids in cool and dark spaces when you aren’t using them will help the flavors stay calm and settled in the bottle.
However, one cool and dark place that you shouldn't keep them is the one place you probably thought of when this article started. The refrigerator is one of the worse places you can store an e-liquid. Though keeping e-liquids in the fridge for short periods of time is fine, long-term storage will cause flavors to disappear over time. Flavor molecules, as well as sometimes being volatile, have a tendency to bond to each other over time. This process is called 're-crystallization', and will cause all of the flavor to fall out of the liquid and into the crystals. When e-liquids are stored in the fridge, this process is significantly more likely to happen. Furthermore, condensation may occur inside the bottles when they are in the fridge. By taking a bottle with liquid in it from room temperature and placing it into the fridge, there is a much higher chance that condensation will form both inside and outside the bottle. Condensation will both water down the liquid and promote the growth of potentially harmful bacteria.
Storing your e-liquid in a cold and dark space is a great idea if you want to keep it for a long period of time. Don’t forget that you shouldn’t keep it in the fridge, and you will be golden to keep that e-liquid tasty and fresh for months on end!