Yoomi Self Warming Bottle 240ml. wait for 60 seconds: ready to use! charge the warmer push the button wait for 60 seconds: ready to use! To charge your yoomi simply place the warmer in a pan of water (or steam steriliser) and boil for 25 minutes. Once charged, your warmer stays charged and is ready to use whenever you need it. Time for a feed? Simply fill your bottle with EBM or pre-mixed formula. Assemble your bottle, press the orange button, wait 60 seconds and feed away! yoomi is the perfect way to warm baby's feed whether you're on the go or at night. What's more the yoomi bottle combines style, comfort and convenience and is a great bottle on it's own.. Before using your yoomi please take some time to read our instruction booklet, which can also be downloaded below: