It's best to follow manufacturer's instructions to ensure you're producing a safe fermented product. If your machine stops working or shuts off mid-cycle, do not eat the yogurt. Also, make sure to clean your device after each use. Bacteria can fester in nooks and crannies and can contaminate your yogurt if you don't correctly disinfect your unit. Otherwise, it’s a very safe process that has been used throughout history to conserve foods.Fermented foods have surged in popularity once again because of their unique taste profile and health benefits.