Adding sugar to adjust SG

[Torin Price]

I have just juiced my grapes from my Dad's vine. Living in Scotland the grapes tend to be a bit sour but this year they're as sweet as they have ever been due in part to the warmest summer on record. However my SG reading is at 1.047 and some research has suggested to aim between 1.060~1.090 for a wine. I'd like to make a dry red out of the juice.

Firstly what would people suggest as a SG to aim for? Secondly, to increase the SG how can I calculate the amount of sugar to add?

Bonus question the grapes come from Kippen, Scotland. Kippen used to host the worlds largest indoor grapevine and these come from a cutting of it. Does anyone know what variety of grapes these are?

 

[marc1]

Gros Coleman according to the page I found :

https://theweevine.org/2017/07/30/making-wine-from-kippens-famous-big-vine/