good gin essence that will also work with water to make a non-alcoholic gin
This is probably not specifically relevant to the shop - as it will be a lot of work to manufacture your own to sell, but more useful for everyone with a still already.
So there is a guy on YouTube called "Art of Drink", he makes incredibly interesting videos and recently discussed this very topic of non alcoholic gins. He argued, that most of them are crap, because the dissolved oils in PPM is like 10-12PPM, vs a normal gin, which is like 30-40PPM. My numbers are made up, watch the actual video if you want to know more. He comes up with a solution of taking a normal gin, and then doubling down on the dissolved oils by creating a gin extract - you then put this extract into a little spray bottle, and when you want a non-alcoholic G&T, you spray your glass with your extract and it will be considerably better, and cheaper, than the store bought variety. I recommend watching the video. I've made his hop oil and it is very potent stuff. When I get some gin made up, I will also be trying his non-alcoholic G&T essence.
https://youtu.be/zh4lm0GaTbM