It's important for bottles to be clean. mimijumi bottles are super easy to clean - just toss them in the dishwasher! The wide mouth means you don't need a special brush to clean them, and the simple design (just 3 parts!) makes clean up quick. That being said, sometimes it's good to get them REALLY clean by sterilizing your bottles. Many people use the microwave to sterilize, but with mimijumi you don't want to.
Without getting too scientific and technical, we'd like to explain why.
mimijumi is made of a specially designed nylon. This material allows us to have a bottle that stays as clear as glass, but is also as strong as plastic - it's the best of both worlds. Part of the process that creates this nylon involves itty bitty teeny tiny (totally the technical term) droplets of water being trapped inside the fibers. Those water droplets are what makes the bottles stay clear. When exposed to microwaves, these water droplets can expand irregularly, causing the bottle to deform.
Sterilization of a mimijumi is pretty easy. You can't use the microwave, but you can use a pot of boiling water, and it really doesn't take long, based on the fact that this video is well under a minute!