As Wirecutter’s resident laundry expert, I encounter a new laundry trend or contraption seemingly every day. Still, the recent buzz about lipase — a common enzyme known for its grease-cutting properties — caught me by surprise. Lipase is hardly a new technology; it has appeared in laundry detergents for decades. So why the sudden stardom?It turns out, lipase’s devoted following is rooted in how effectively it purportedly treats two laundry woes: stubborn grease stains and lingering stench (sometimes called odor rebloom or permastank). Both types of soils are caused by oils and require powerful degreasers to remove.But using any old laundry detergent containing lipase won’t necessarily eradicate a pizza stain on your favorite shirt or the funk embedded in your workout clothes. A detergent’s overall formula, as well as its correct use, matter far more than a specific ingredient, lipase included. Here’s why.