my diy juice seems to be lacking flavour and the sweetness my concentrate is good stuff from chefs vapour and i mix at 20% and i use sweet.tart as a sweetner but all my flavours seem to be tasteless they smell really nice but taste wise really dull
Probably too much flavour, if you post the recipe we should be able to help. I increased a flavour by 1% in a pretty good 9% total flavour recipe and it killed off most of the flavour.