There are signs to look out for to determine that an e-liquid has reached its expiration date. The flavour itself will tell you if the e-liquid is no longer good. You will notice a difference in the taste of the e-liquid, as the aroma will no longer be as pronounced as usual. As a result, you’ll be faced with a flavour that certainly feels familiar, but just isn’t as good.

On the other hand, the nose can detect any change in the smell of food. This is just as true for e-liquids. We’re pretty sure that if you have a favourite e-liquid, you surely know its authentic smell by heart.

So you will be able to detect even a small change in its smell. Flavoured e-liquids have very specific smells similar to the flavour from which they are inspired. So, if the e-liquid smells weird, throw it away immediately. 

An expired e-liquid implies a deterioration of its original colour

E-liquids often contain nicotine and you should know that liquid nicotine oxidizes over time. This is especially true if the liquid nicotine is not in a tightly sealed container. 

Oxidation is a natural process. It’s the same process that happens every time you see a peeled potato change colour after a few minutes. The colour change is the result of oxidation. In vaping, this happens when the atoms of the nicotine molecule interact with the atoms of the oxygen molecule in the air. There is nothing anyone can do to prevent this process.

The visible effect of oxidation is the colour change in the e-liquid. The colour will become progressively paler as it oxidizes. Despite a slight colour change, most of the time you will be able to continue using the e-liquid. However, it may be best to discard the bottle if the colour change is too pronounced or the colour becomes too different from what it was before.

An expired e-liquid implies a change in consistency

The consistency of an e-liquid varies from product to product. This depends, among other things, on the quality of the e-liquid you have purchased and the ingredients used in its manufacture. An e-liquid with high levels of propylene glycol will run smoother. In contrast, an e-liquid with a high vegetable glycerin content is thicker.  

In addition, it is also possible to see an accumulation of residues at the bottom of the bottle. At this point, you simply have to shake the bottle slightly so that the residues are distributed again in the e-liquid.

However, if you continue to see residue after vigorously shaking the bottle, then it is best to stop using the e-liquid in question. If the consistency of the e-liquid becomes suspicious, don’t hesitate to throw it away and buy a new product.