It would be simpler to pack up everything you own and move to a new community, state or country where the grocery stores do sell fermented black beans. Yes, you can ferment the beans yourself. But first, look at what Susanna Foo says about it in her lovely book, Chinese Cuisine (Canada, UK): “Our Cantonese neighbor always made her own fermented black beans. She would mix black soybeans with salt, spices and gingerroot and let them sit out to ferment. She then sun-dried this concoction in her backyard for many days. During that time, the whole neighborhood acquired a pronounced smell, and my mother would complain that the odor was offensive.”
Ms Foo goes on to say how much she has come to appreciate fermented black beans as an ingredient, but pointedly does not give a recipe for making them yourself — and neither does any other Chinese or Asian cookbook that we consulted. Seriously, unless you live in the middle of nowhere, get on the phone with the manager of every nearby grocery store and shame them into getting fermented black beans on the shelves. And if you are in the middle of nowhere, order some online and pay the shipping, for heaven’s sake.