I have had my sourdough starter going for almost two years. Lately, I have noticed a sulfur-y smell once my dough has risen overnight. The smell is not in my starter- just in the dough, once it has risen overnight. My starter rises great, isn't discolored, and I feed it everyday. I switch it to a clean jar every couple days too. Also, the dough of whatever I am baking rises great- but, is this normal for the dough to have a sulfury smell, particularly upon taking the cover off the bowl? I don't want to bake something that is harmful to anyone! Any insight is most appreciated- thank you!!