Bread Problem

As some of you know, I've been making bread a long time, about forty years now.  I've used those little cakes of yeast (rarer now--very common when I started, to find them in the refrigerated shelves in stores), active dry yeast, "Rapid-Rise" dry yeast, active dry yeast in little brown jars, bulk dry yeast in sealed 1 pound plastic bags, (bought years back from some place in Austin I've now forgotten--it was where I bought flour in bulk.)   I've made bread abroad, using locally available...