If the black spots are from a fungus, there are several culprits to choose from. The diagnosis, symptoms, and treatments are similar.  The spots may appear anywhere on the leaves, for example, at the center, on the edge, on the leaf or stem. A look underneath the leaves should reveal a fungal growth, like black specks or a fuzzy substance.  

It's possible that the disease will progress slowly enough that you can still use your basil and hops.  It is safe to eat leaves from the basil plants, but be prepared to pull out, bag up, and throw out infected plants if they get completely affected.

Management includes using resistant varieties of basil plants or seed that are less susceptible, and possibly applying fungicides. Using watering practices that minimize leaf wetness and reducing humidity to obtain conditions unfavorable for disease development may also suppress fungus diseases.