Whether you’re team Stanley Cup, team Frank Green or team Chilly’s, there’s a good chance you have a reusable water bottle (or if you’re like me, you have three of them!). But here’s a hard truth: I’m probably not cleaning my water bottle enough – and neither are you. While reusable water bottles can reduce your plastic waste and prevent you from having to buy bottled water when you're out and about, they can also harbour some nasty bacteria and gunk.

I tapped the Good Housekeeping US Institute’s kitchen lab director Nicole Papantoniou for advice on how often to wash reusable water bottles and the best methods of doing so.

several ecofriendly reusable water bottles placed on a shelf
Cristina Oller Real//Getty Images

It’s easy to assume a water bottle is clean after simply refilling it with water day after day. You are the only one drinking out of it, after all. But if you tend to go days without giving it a good wash, you might want to work it into your daily routine.

‘I’d recommend cleaning your water bottle daily, but I’ll admit that sometimes I’ll go two or three days tops without washing it,’ says Nicole. ‘Bacteria can build up easily, which can make your water taste bad and can even cause sickness.’

Cleaning your water bottle every day might seem inconvenient, but most nowadays are dishwasher-safe. Just throw it in there at the end of the day with the rest of your dishes so it’s fresh and clean the next morning.

Tip: Always check the manufacturer’s instructions before putting your water bottle in the dishwasher.

If your water bottle isn’t dishwasher-safe or you want to give it an extra deep-clean, here are a few steps to follow when washing by hand.

  • Dissemble all pieces of the water bottle before cleaning.
  • Wash the outside of the bottle using a sponge and hot, soapy water. Clean the inside with a bottle brush.
  • Pay special attention to the mouthpiece and all crevices of the bottle, including the straw. ‘I always give my straws a good once-over with a straw brush to remove any buildup,’ says Nicole.
  • Let all pieces of the water bottle dry. ‘Mould can grow under silicone pieces if they’re not removed and allowed to dry completely,’ says Nicole.

To eliminate any bottle-cleaning frustration, try a few GHI expert-recommended products. Keep a dedicated bottle brush right by your sink for everyday use or carry a compact Tot Bottle Brush for when you’re on the go. Looking for something even more travel-friendly? Bottle Bright tablets are perfect for cleaning your water bottle regardless of where you are.