The quince becomes yellow, covered with a light down, it is time to pick it. It can remain in the cellar for a while longer before finding its way to the jelly basin.
A board with a notch at one end to wedge the branch, will support it to prevent breakage. Quinces are very heavy.
If you have a quince tree, here is what you can do in autumn - winter for him.
Here you will find disease-resistant heirloom varieties