Nature helps us out a lot with pears due to the typically drier climate and hot sun in the summer. Our dry climate reduces fungus numbers in the summer that would rot pears. July and August have virtually no rain most years but lately we to have had exceptions. When we tilt the pear up and they fall off in our hand than we know they are ripe. I can’t imagine how hard duchess would be to pick let alone ripen properly in a different climate that had higher annual rainfall. In my opinion our growing season would ripen them better if it was slightly longer at times but most years it’s ok. I’ve picked them in November before when my hands were pretty cold.
The regional differences aren’t too surprising, except the reliability of judging ripeness by a clean stem break. That is not a reliable calibration here for me- once they reach that point they often immediately drop to the ground. Seckel is easy because you can wait for a dramatic change in color. With Harrow Sweet, you can also do this but neither of them last more than about 6 weeks in storage if picked tree-ripe. Both can get soft on the tree and still be great eating, but you will have a lot drop is you do that.
Mine ( if they were the truly the Duchese pears) were very late ripening as well. I could eat them sooner like an apple, before I stored them to get riper and softer to make pear butter with them. I did like eating them when they were riper like an apple.
They were as big as my open palm of my hand. Very heavy. Mine were blocked by most of the sun by some huge walnut trees so they were never any color but green. No blush. They did look exactly like the ones in your pictures.
Maybe you could start making jam with them so that they do not have to be green?
I don’t eat much jam, but it’s nice to be eating pears out of the fridge well into winter, even if they are not the very best.
Duchesse d’angouleme is the only pear I know of that looks and ripens like that. It’s also the only pear I grow with lumpy skin.