The more exposure to Heat, Light and Air e-liquid gets, the darker it will become as the nicotine oxidises. E-liquids with a higher nicotine content will see this process accelerated. We recommend using a smaller travel bottle when buying larger bottles. We recommend storing juice in a cool, dark place with minimal exposure to Heat and Light. Storing e-liquid in the fridge will also slow down the “steeping” process. We always recommend keeping all e-liquids out of the reach of children and pets.