Yes that is what I recall people say for fermentation. It is called Brix. And from my reading the perry pear seem to be as you described for your small pear producing tree. I tried grafting perry grafting wood and while the grafts took, the resulting trees did not do well in northwest florida. Perhaps callery hybrid pears would work here. Florida is hard on many pears such as Bartlett. I have specific gulf coast cultivars that do well here.