Is my melon cherentais vert ripe?
With the caveat that I have never grown this particular melon, generally they are at maximum ripeness when they are between half and full "slip". Slip meaning that the point of attachment of the stem to the melon begins to crack in a circle around the stem. At full slip, (the circle being complete) the melon is very ripe and should be picked and eaten or chilled very soon.
Lacking the space for melons of this type to sprawl, I grow them up on fences with a square of plastic net attached to the fence beneath each. (cut up panty hose work well, too) When the melon reaches full slip, it drops into the net and I collect it for morning breakfast.
Hope this is of some help.
My test for a charentais would be the same as for any other melon - is there a slight give when I lightly press the ends and does it smell of melon.
A ripe melon is a rare thing in my experience so I'm not able to taste them often. You see so many people in the supermarket who just pick up a melon and put it in their trolley without any test - what a waste of their money.