Greek yogurt sales have exploded over the past decade. These products are typically higher in protein and are thicker than regular yogurts because they are more heavily strained to remove liquid whey and lactose. However, the byproduct left behind from Greek yogurt production poses a challenge to manufacturers who must dispose of increasing amounts of acid whey. Acid whey, named from the high concentration of lactic acid present in the liquid, is too acidic to be released into waterways without treatment. Although originally regarded as a waste product, recent advances in filtration techniques and biodigester utilization have led to several options for the management of acid whey. Reverse osmosis and ultrafiltration allow Greek yogurt producers to separate whey into acids, sugars, and minerals and then divert the remaining water to treatment plants. Acid whey is a good source of sodium, potassium, calcium, and phosphorus. Lactose in the acid whey can be converted by enzymes into galacto-oligosaccharides, soluble fibers often included in cereals and snack foods to enhance digestive health. Additionally, acid whey is a viable source of fuel to create methane in a biodigester system. The large quantities of acid whey generated in Greek yogurt production make it imperative that treatment options be further developed and harnessed to allow for the sustainability of this industry.