Shortfills have become very popular since TPD kicked in back in May 2016, but is it a reliable method of getting your liquids without having to buy them in 10ml bottles? DIY by concentrate is another popular method, but requires more thought and materials – which is the better option? The method I prefer to use is mixing my own e-liquid with concentrate, my reasoning being that I can buy the flavours/concentrates I want and add my own Nicotine, VG, and PG to the desired mix. Shortfills don’t work. Why? Let’s take a 3mg 70/30 mix for example. You buy either 40 ml or 80 ml and then add your own unflavoured nicotine shot to the mix – give it a shake, off you go. What you’ve done is dilute the mix by either 10 or 20ml. This is going to make a massive difference to the overall flavour, also depending on the ratio of your nicotine shot you could also be changing the VG/PG ratio, ending up with something different to what you originally wanted. If you want to increase your nicotine mix, let’s say 6mg or even higher, you dilute even further. Some flavours are strong, and this dilution wouldn’t be noticed that easily. Other, more refined mixes suffer the most. I bought a 100ml shortfill (80ml plus 2x 10 ml nicotine shots) of one of my favourite flavours as well as a 30ml bottle of concentrate – same flavour. I mixed both at the same time and steeped them for six weeks in the same place – same temp, same humidity. Identical. The short fill was weak in colour and flavour, the 100ml I made from concentrate looked and tasted as expected. I tried giving the shortfill a few more weeks, reckoning the experiment had already proven my hypothesis, but the results remained the same. The only place for it, after all that, was the waste bin. This dilution effect would be fine if the e-liquid makers took it into account, but this would mean different concentration mixes and different PG/VG ratios for every flavour available. Practically, this is not feasible – time, cost, and storage means they will have to stick with a regular 70/30 or 80/20 base. As stated earlier, I usually mix from concentrate as I know exactly what is going into my liquid – the mix, the ratio, the percentage of concentrate I want to use. But I have been lazy in the past and have purchased a few short fills. My results have been listed above. That’s not to say that mixing from concentrate is perfect and infallible. There’s the initial cost in equipment such as beakers, syringes, bottles, and needles – plus your nicotine, VG, and PG – before you even buy your concentrate. Some of these things are easier to find than others, but it’s still an expensive initial set up. With the concentrate, that’s easy to find online – but I’ve always found it best to stay with the well-known stores, like Chefs Flavours. The amount of concentrate percentage needed to mix it should be listed on the bottle, but again in my experience a lot just state 20%. Personal preference may play a part, but in my experience 20% seems the average mix amount. It’ll take a few tries to find the right combination. Before TPD came into effect, all e-liquid was mixed to a dedicated recipe, with new flavours being tried and tested at a variety of strengths to give the optimum taste for the widest audience. Now, that process seems to have been pushed on to the consumer – the 20% on the bottle is a quick and easy average to give, and I have my suspicions a lot of flavours aren’t fully tested at varying strengths and 20% is just quickly, and easily, slapped on the bottles. For example, my current flavours and mixes are: custard (22%), mums milk (24%), RY4 (14%), and blackcurrant and aniseed (17%). An average of 19% volume. Not a million miles from 20%, but if I’d stuck with that suggestion some flavours would have been too weak and others far too strong. These are all my thoughts on the pros/cons of shortfills and concentrates. You may have a different experience or not agree, but I wanted to share my findings.