Grapes - Under glass or outdoors?

[Scarlet]

I grow mine on a south facing wall outside. It does very well.

[veggiechicken]

I grow one grape vine both outside and inside a GH (led through a hole in a glass pane). The inside grapes are ripe now, the grapes outside are still green.

[Scarlet]

Ah, mine are still green. They usually ripen at the end of Sept. just in time for my picnic at the Malvern Autumn Show