BoyPete wrote:
There is a very old vine in my mums garden, laden with masses of grapes.
They are too tart to eat, so I thought 'wine'
Some are ripe to the point of being soft, others are still green. I have all
the equipment to make wine from concentrates, but don't know how to process
the grapes. Can I mix the less ripe with the ripe. That'll do for a start

Just like with the apples, I suspect, you could freeze what is ripe
until the rest of the grapes have catch up and then crush the lot at
the same time. Frosen fruits are easier to crush into bits ! That's
what I would do. Now if you are impatient to start - I wouldn't mix the
two, ripes and not ripes.