How Many Bottles Should You Sterilise at Once?
The answer to how many bottles you should sterilise at once is simple: as many as your steriliser can handle in one cycle. There is no benefit to sterilising fewer bottles than your unit can fit – you'll just end up running more cycles.
Here's how to work out what batch size makes sense for your routine.
How many bottles fit in a steriliser?
It depends on the type of steriliser:
- Microwave sterilisers: typically 4 bottles (some hold 5-6)
- Electric countertop steam sterilisers: typically 6-8 bottles
- Combined wash-sterilise-dry units: typically 6-8 bottles plus accessories
- UV sterilisers: varies, typically 6 bottles plus smaller items
Capacity is usually listed in the product specifications. If you're buying a steriliser specifically to batch sterilise, choose a unit that holds at least 6 bottles.
How many cycles do you need per day?
For exclusively bottle-fed newborns on 8-10 feeds per day with a 6-8 bottle rotation:
- One batch covers most of the day if timed well – morning batch for daytime feeds, second batch in the evening for overnight feeds
- Many parents find one batch in the morning and one in the evening (or just before bed) is the most manageable routine
For combination feeders on 4-6 bottle feeds per day: One batch per day is usually enough with a 6-bottle rotation
For babies 6-12 months on 3-4 bottle feeds per day: One batch every day or every two days depending on how many bottles you have in rotation
Does it matter how full the steriliser is?
For steam sterilisers, a full load is fine and doesn't affect effectiveness. Steam is distributed throughout the chamber regardless of how many bottles are in it, as long as:
- Bottles are loaded with openings facing downward so steam can reach the interior
- Components aren't so tightly packed that steam can't circulate between them
- Teats are removed from bottles for sterilising and placed separately
A half-full load is also fine – you're not wasting sterilising effectiveness by running fewer bottles.
What about sterilising accessories alongside bottles?
Most sterilisers can accommodate bottle accessories in the same cycle as bottles – teats, rings, caps, dummy clips, and smaller breast pump parts. Load them in the accessory tray or basket, checking they don't block steam circulation.
Breast pump parts (shields, connectors, membranes) can typically be sterilised alongside bottles in the same cycle, which is convenient for parents who are both expressing and bottle feeding.
If you want to batch sterilise a full day's supply in one go, the Bebello 4-in-1 handles up to 8 bottles per cycle – and washes and dries them too, so you're not running the dishwasher and steriliser separately.
Frequently asked questions
Can I sterilise too many bottles at once?
Only if the load is so packed that steam can't circulate properly. In a correctly loaded steriliser at recommended capacity, a full load is as effective as a partial one.
How long does sterilising multiple bottles take vs one bottle?
The cycle time is the same regardless of how many bottles you load – sterilising 8 bottles takes the same amount of time as sterilising 2, which is exactly why batch sterilising saves time overall.
Can I mix bottle brands in the same steriliser?
Yes. A standard electric steam steriliser is brand-agnostic. You can sterilise MAM, Tommee Tippee, Dr Brown's, and Philips Avent in the same cycle.
What if my steriliser is too small for all my bottles?
Either run two cycles (or two sterilisers) or consider upgrading to a higher-capacity unit. Alternatively, an all-in-one machine with wash-sterilise-dry capacity may handle a full day's supply in one cycle.