Soybeans seem to behave a little differently in different climates, too. I noticed farther north (and farther away from the damp air off the ocean),beans will often dry down enough in the pods to combine but the stems will still be tough and greenish. Where I live in west central New Jersey, we still get some of that ocean moisture, despite being "almost Pennsylvania", and often the beans won't drop below 18% until they are brown from frost.