My wife is going through this at the moment with her drinks product. You cannot just stick liquid in a bottle (even water) and sell to a customer.....you need to get the whole "recipe" and "production process" approved.....only then can you finalize labeling and only after that can you then think about production. You need to work with a food technologist...talk to the food standards agency...they might put you in touch with a food college that has lab facilities and the people to help you. As part of the recipe process you will get into things like 1) citric levels 2) bacteria, acceptable levels for human consumption etc 3) how you fill the bottles, are they serialized...if so how? 4) your supply chain, are the ingredients acceptable and certified. ... its fascinating actually.....but a lot of work. and it will cost you at least £5k before you even fill your first bottle. Also, your own bottling production line alone might cost up to £50-100k... so outsourcing that is probably better. I could not believe how difficult it is to get a product to market, I have a lot more respect now for the people on Dragons Den that have got their product to supermarket shelves.