How to Use a Microwave Steam Steriliser Bag

Quick answer

Using a microwave steam steriliser bag is a fast, portable way to eliminate 99.9% of bacteria from baby bottles and accessories. Follow these steps for safe, effective sterilisation every time.

Step-by-step instructions

1. 1. Prepare the items: Wash bottles, nipples, and accessories thoroughly with warm soapy water and rinse well. Disassemble any parts that come apart. Shake off excess water — items should be damp but not dripping. Common mistake: placing unwashed items in the bag. The steam sterilises, not cleans, so all items must be clean before sterilising.
2. 2. Add water to the bag: Open the microwave steam steriliser bag and pour in the amount of water specified on the bag — typically about 1–2 ounces (30–60 ml). Do not overfill, as excess water can prevent proper steam generation. Checkpoint: use fresh tap or filtered water each time. Reusing water may reduce effectiveness.
3. 3. Arrange items inside: Place the clean, damp items inside the bag, ensuring they are not stacked or touching each other too closely. Leave the bag's seal slightly open to allow steam to escape during heating. Common mistake: sealing the bag completely. Steam needs to expand, so leave the seal open as directed.
4. 4. Microwave on high: Place the bag upright in the centre of the microwave. Heat on high power for the time recommended on the bag — usually 3 to 5 minutes depending on microwave wattage. Do not exceed the recommended time. Checkpoint: if your microwave wattage is lower than 900W, you may need to add 30–60 seconds. Check the bag's instructions for wattage adjustments.
5. 5. Remove and cool: Carefully remove the bag using the designated cool-touch handles or corners. The bag and contents will be very hot. Let them cool for at least 2–3 minutes before opening. Open the bag away from your face to avoid steam burns. Common mistake: opening the bag too quickly. Steam can cause burns, so always wait and open with caution.
6. 6. Use or store items: Remove items with clean hands or tongs. Use them immediately or store them in a sterile, covered container. Do not touch the inside of bottles or nipples after sterilising. The bag can be reused up to 20–30 times; replace when it shows signs of wear or damage. Checkpoint: after use, air-dry the bag inside out before storing to prevent mould. Replace the bag if it develops holes, tears, or a persistent odour.

Product used in this guide

• Dr Brown's Microwave Steam Steriliser Bags: Dr Brown's Microwave Steam Steriliser Bags eliminate 99.9% of common household bacteria and germs, and are designed for fast, effective sterilisation at home or on the go. This means you can achieve hospital-grade hygiene for your baby's feeding gear in just a few minutes, whether you're at home or travelling.