Most parents sterilise their baby's bottle by boiling it on the kitchen stove or heating it in the dishwasher. These conveniences aren't readily available while travelling, and other sterilisation equipment and techniques are needed. Baby bottles can usually be cleaned with soap and water, but if you're travelling in areas where water sources may be impure, you should sterilise the bottle to ensure germ removal. Impure water sources used to wash a baby bottle can lead to internal parasites.
Wash the bottle with warm water and soap using a bottle brush. Rinse the soap off the bottle.
Place the bottle, its cap and its nipple inside of a microwave sterilizer bag. Pour 120ml or about 118ml of clean drinking water into the bag and seal it tightly.
Place the bag on the turntable of a microwave. If the microwave doesn't have a turntable, place the bag on the floor of the microwave. Do not put it on a metal rack if the microwave is so equipped.
Heat the microwave for two minutes at 1100 watts, three minutes at 800 to 1100 watts or five minutes at 500 to 750 watts. The time depends on the wattage of the microwave. You can usually find this on a label either on the front, sides, bottom or rear of the microwave.
Remove the sterilizer bag from the microwave after it has finished using oven gloves. Hold the bag away from you at arm's length over a sink and let the hot water pour out through the steam vent. Keep this vent away from your face.
Open the bag and remove the bottle, cap and nipple. Dry the parts with a paper towel and store them in a zip-lock bag or plastic container with a lid.
Microwave sterilisation bags can usually be used more that once.
Never assume that the water coming out of the tap in a remote part of the world is drinkable. Use only microwave-safe bottles in the microwave bag. Avoid heating the bag for longer than the prescribed times or the bottle parts may warp.