As veteran vapers at this point, whether we like it or not we've all had those idiot moments when we left juice out in a tank or bottle for too long and it ended up tasting like, well, shit. I'm going to give you a few tips on how to make your E-juice last longer and taste better in the summer because there really are a few things to keep in mind.
First off, we all know the two main ingredients in E-Juice, PG (propylene glycol) and VG (vegetable glycerine). However most people don't know that while nicotine and VG are heavily effected by light and heat PG is not. So take note that if you are vaping 100% vg or heavy vg liquids, it is even more important to take care of where and how you store these.
So we all know by experience that the enemies of our precious E-juices are light and heat. So we can do a few things to combat these elements to keep our juice good, some of them are common sense and some are not.
Store your juice in glass bottles, not plastic. While being more cheap and convenient, plastic bottles won't protect your juice anywhere near as well as glass from light and air.
This one is pretty much common sense, but this article wouldn't be complete without mentioning it. When not in use, store your liquids in a cabinet or closed container. The point being that you are keeping them out of the light. Also, make sure to store liquid in cool areas or near room temperature.
If you buy large amounts of liquid at a time, you can store them in a fridge or a freezer. I myself have never tried this, as I buy less in bulk and more in small bottles of different juices. The fridge/freezer will slow down the breaking down of the molecules in the juice, resulting in it staying better for longer. However if you take this route i would suggest occasionally taking the juices out and stirring them to stay on the safe side. One other thing: GLASS BOTTLES OF JUICE WILL NOT SHATTER IN THE FREEZER. This is something I hear all the time, and it's not true. PG and VG will never reach their freezing points in your freezer, and they will not expand so this will never happen.
Use less fruity flavors. The esters in fruity and more flavored juices will act as a catalyst to your juices breaking down, thus making the life of your juice shorter.
Don't mix juice! Mixing juice drastically alters it, upsetting the PG/VG balance etc, and hugely affecting the storage life of your juice.
Last one: Don't keep your setup in the car. I use a Sigelei 150W with a TFV4 tank, and every time I have ever done this I end up with less juice and a worse taste. It will mess with your juice, and your coil. If you have to do this, leave it in a glove box or compartment out of the sunlight.
If you follow the tips that I have offered up in this article, you will see an improvement in the life and quality of your e-juice. My final suggestions are to buy juice in smaller quantities and bottles (30mls or less) and use a glass bottle. Keep the juice out of the light and heat and you will see results!