How to Sterilize Breast Pump Parts with a Silicone Bag
By Grove Collaborative: Eco-Friendly Home Essentials ... | Published: 2026-11-03
Category: How-to Guides
Steam-clean pump parts in minutes with a reusable silicone bag. Follow these steps for safe microwave sterilizing at home or while traveling.
Quick answer
Use a reusable silicone sterilizer bag: add water, load clean pump parts, seal, and microwave for the time your bag specifies. It replaces bulky countertop sterilizers and works in any microwave, including while traveling.
Why a silicone bag beats a countertop sterilizer for pump parts
Countertop steam sterilizers take up counter space and need a dedicated outlet. A silicone bag collapses flat, stores in a drawer, and travels in a diaper bag. For pump parts and bottles, that convenience matters more than capacity.
The trade-off is batch size. A bag holds one pump session's parts or a few small bottles, not a full day's collection. If you pump exclusively and prefer to sterilize once daily, you'll need two or three cycles rather than one large load.
What to check before you begin
Confirm your pump parts are microwave-safe. Most silicone, polypropylene, and glass parts are, but check the manufacturer's instructions for any part with metal components or a closed electronic unit. Never microwave a pump motor.
Also check your bag's maximum fill line and recommended water volume. Overfilling can cause the bag to bulge or leak; underfilling risks scorching. The Haakaa bag includes guidance, but always follow the specific instructions that came with your bag.
Step-by-step: sterilizing pump parts in a silicone bag
- Wash parts first: Hand-wash pump parts with warm soapy water and a bottle brush, then rinse thoroughly. Sterilizing does not remove milk residue or soap film. Skip this and you'll bake milk proteins onto the parts, which is harder to clean later.
- Add the right amount of water: Pour in the water volume your bag specifies—often a few tablespoons. Use tap water unless your bag's instructions say otherwise. Too little water can scorch the bag; too much can cause boiling water to spill when you open it.
- Load parts without overcrowding: Place parts in a single layer or loosely stacked, leaving space for steam to circulate. Keep valves, membranes, and small pieces in a basket or mesh bag if your sterilizer bag includes one. A packed bag steams unevenly, so some parts may not reach sterilizing temperature.
- Seal and microwave: Close the bag according to its instructions and microwave on high for the recommended time. Start with the shortest time your bag lists, then adjust if needed. Microwave wattage varies; if your bag gives a range, use the longer time for lower-wattage microwaves.
- Rest before opening: Let the bag sit closed for the time stated in the instructions—usually a few minutes—so the steam finishes its work and the contents cool slightly. Opening immediately releases a burst of hot steam that can burn your face or hands.
- Open away from your face and drain: Open the bag slowly, pointing the opening away from you. Carefully pour out any remaining water and place parts on a clean, dry towel to air-dry. Never microwave the bag empty or reuse water from a previous cycle.
- Store dry and clean: Once parts are completely dry, store them in a clean, covered container. Wash the silicone bag with soap and water after each use and let it air-dry fully before folding. A damp bag can grow mildew; make sure it's completely dry before storing.
Product facts
- Reusable, Silicone Multipurpose Steamer & Steriliser Bag: Reusable, non-toxic food-grade silicone bag designed for microwave steam sterilizing. It replaces disposable sterilizer bags and bulky electric units, so you can sterilize pump parts with just water and a microwave.
Reusable, Silicone Multipurpose Steamer & Steriliser Bag
