I had a Hollandisch grandmother, but she died before I was old enough to cook. I learned how to stew the hard pears from a tree in our yard from an online recipe. It specified Port wine, and while they were good, your version with Creme di Cassis sounds much better.
We have a pear tree that produces hard pears that never get sweet or soft. They must be the type that need to be cooked. I never thought they tasted good enough to make it worth the effort to can them, but this sounds like it might be the way they need to be treated. Thanks for the article.
My D.H. says they sound like "sickle pears". They grow in Delaware and mid-Atlantic states. They, too, are small and hard as rocks; cooking pears. His family ate them fairly often. His mother is of German and Dutch ancestry. We eat regular pears simmered in wine and spices. Not cooked as long.
At my farm in Mississippi we have the hard kind that never get sweet. They are delicious poached in Port Wine and people there can them and make preserves out of them, but I never have time.
Here in New Mexico, I have 4 pears, mostly too young to bear but two may do so this year. One is a "Seckel" pear. It is very small and very sweet, but you have to wait until September for them to ripen. I haven't had lots yet, but I had about 8 last year and ate everyone without cooking in any way. They are also called sugar pears. You can see them in Plant Files.
Surely, the ones that your husband's mother had weren't Seckel pears. They sound more like the ones at the farm which are similar, if not identical to Keiffer pears.
I think all pears are yummy simmered in wine and spices. You just adjust the cooking time according to their consistancy.
It has taken me a long time to learn how to deal with pears -- when they are ready to eat, etc. etc. But now, I am addicted!