You may notice your nicotine transform into brownish/ yellow color, and develop a slight peppery taste. This is the work of oxidation.
The following three components will effect the quality of your Nicotine as they can work together to promote oxidation.
Theoretically you should only buy as much nicotine as you are willing to use in one mix. When experimenting with new flavors, you may find yourself using less nicotine. When experimenting with new flavors, you should buy a nicotine strength as close to your final nicotine (target nicotine) as possible. This will prevent you from opening and closing your nicotine too often. The stronger the nicotine, the quicker is will spoil.
2. UV Light
UV light is another enemy of Nicotine. Nicotine should be stored in a cool, dark place away from children and pets. If possible, store your nicotine in amber glass boston rounds. The amber color will help filter the UV rays, and the glass will create a better barrier than most plastics.
Heat is one of Nicotine's most ruthless enemies. You will want to make sure your nicotine is stored in a cool away, away from pets and children. Nicotine can be stored in a freezer preserving the shelf life. If stored in a freezer you will need to have a dedicated freezer with a lock to prevent any unwanted persons from injury. Nicotine will not freeze.