Now that I'm concocting ejuice on a grand scale, I've been pondering the interaction between nicotine and the juice itself. I realize that most commercial juice sold in the UK comes with separate nicotine shots, and this has got me thinking. Is there any benefit or disadvantage of omitting nicotine when testing/trialing recipes? How much of an effect does nicotine play as part of the steeping process? Is it an essential component, and if so, how do commercial producers compensate for not having nicotine in their juice? Would I be sensible in creating recipes without nicotine, and if they are decent enough to vape add the nicotine afterwards? It seems pointless adding nicotine if potentially some of the juices are going to be binned, but at the same time, if it is an essential part of the steeping process I don't want to be misled by a juice potentially having different characteristics caused by adding the nicotine post-steep. So when do folks here add nic, before or after steeping?