High lipase activity refers to a natural enzyme in breastmilk (lipase) breaking down fats more quickly than usual. Lipase is essential and beneficial. It helps babies digest fat and absorb nutrients. In some cases, though, this fat breakdown can cause stored breastmilk (refrigerated or frozen) to develop a soapy, metallic, or rancid smell or taste over time. Importantly, milk with high lipase activity is still safe and nutritionally valuable! The issue isn’t spoilage, it’s that some babies are m