I echo the TFA Grape Juice sentiment but I would also layer on some Ginger Ale and Champagne, maybe even a hint of Gummy Candy, Cotton Candy (EM) and some Citric Acid to really bring out the sweetness and the fruitiness.

This is just a first crack at a recipe but could be a good starting point:

• Grape Candy [TFA] - 6.5%
• Grape Juice [TFA] - 1.5%
• Gummy Candy [TFA] - 1.5%
• Champagne [TFA] - 1%
• Ginger Ale [TFA] - 1%
• Citric Acid (10% in PG) - 0.5%

Ethyl Maltol for added sweetness and to dampen some of the sharp notes.

Licorice if you want grape vines

Citric Acid for a little tart

TFA Sour (Malic Acid) for sour candy

FA Rose as an addition at a very low percentage will give you a little b-damascenone, which will enhance the authenticity of grape juice

An addition of Furaneol would be make it a lot more candy like. Look under the TFA component list for sources of it (labeled as Pineapple Ketone). Highly recommenced either of their strawberry flavors (ripe is probably best) as a supporting note.

http://www.aroxa.com/wine/wine-flavour-standard/2-aminoacetophenone/. Another enhancer if you are feeling frisky.

Try mixing TFA Grape Juice with grape candy. I think those flavors are better together than either of them are individually. Start by replacing 1 or 2% of that 10% Grape Candy with Grape Juice.

A lot of people here are recommending citric acid and I'm going to suggest not wasting your time with it. It will just gunk your coils and any difference in taste you experience is likely imaginary.

2 to 4% TFA Sweet and Tart will make a fruit into a fruit flavored candy.

Instead of citric acid I suggest a couple drops of lemon concentrate to make it pop. Also a little bit of FW hard candy will give it more of a sweet candy taste without adding sweetener, it smells exactly like melted jolly ranchers so that would be a good thing to add!