Question: what are the solids in balsamic vinegar?
Answer: If it is really "floaties" or a gelatinous mass, it is vinegar "mother" that forms in unpasteurized vinegars. If you have mother in a bottle, the vinegar will tend to get weak and light in color. You can use the mother to ferment new vinegar from wine but it wont be the same as your current balsamic.