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The story
Water bottles used every day are prone to developing slime on the inside of the body and around the packing, even when you think you’ve washed them properly. An article in which AERA with Kids interviewed an infection-control expert explained what that slime actually is and how to care for kids’ water bottles to keep them clean. In response, 5ch users exchanged views on specifics like using oxygen bleach on stainless steel, why barley tea and mineral water make bacteria multiply more easily, and the point that the very structure of drinking straight from the spout causes bacterial growth — along with concrete washing methods and bottle choices.
Published 10/20 (Tue) 7:00 AM
AERA with Kids+
The water bottle you send your child off with every day. Even when you think you’re washing it, slime can build up before you know it. In particular, the inside of the bottle and the packing take extra effort to clean, so care can easily fall short. In fact, those working in childcare and education say they do sometimes see kids’ water bottles with built-up grime. We asked an infection-control expert about what that slime actually is and why daily care is necessary.
Source: news.yahoo.co.jp / Original article here
What people said
Isn't stainless steel supposed to be fine?
I've been using it anyway.
You can use oxygen bleach, so
I just dunk the whole thing in a basin.
I use a bleach that isn't Haiter.
Barley tea is nutrient-rich, which means it spoils easily.
It's made from barley, the same stuff used for booze, so of course it spoils easily.
They're actually meant for storing pasta upright, but still.
Makes you wonder about the microplastics though.
But with a water bottle, putting ice in it keeps it cold enough that bacteria don't grow either.
I'm a little worried, but I can't go back to a bottle that's a pain to wash.
I just shove a bottle brush in and scrub it,
then wash the outside and lid with a regular sponge and I'm done.
Like it says in Re: #1, the packing and the mouthpiece stay at room temperature,
so that's exactly where the slime forms.
It must be a pain for moms to wash.
I've switched to only using foreign-made ones.
Some foreign-made ones are a nightmare to wash too.
You're just not well informed.
so you should scrub it with a brush and sterilize with boiling water every day.
Also, even boiled barley tea picks up bacteria easily.
Best to pour it from the bottle into a disposable paper cup before drinking.
By foreign standards a dishwasher gets things clean,
but by Japanese standards it isn't clean at all.
Though running it through multiple times doesn't seem to help either.
The bacteria and biofilm that form in a water bottle work the same way as dental plaque.
Just buy one whose lid doubles as a cup and use that instead.
They barely sell that type of bottle anymore these days.
Setting aside the big ones for school trips,
the small ones that empty after a few sips are basically all made for drinking straight from the spout.
Probably just rinsing it.
When I take mine traveling I just scrub it with a paper towel, no detergent, and it never gets slimy.
If you put tea or juice in it, wash it with Haiter.
Juice in a water bottle?
Never even occurred to me.
Once I switched to just water,
not only did the bottle stop getting dirty,
my teeth got whiter too (・∀・)
Even my kitchen faucet gets slimy and grows black mold even with a water filter attached.
And it's only supposed to be putting out water.
I do it the opposite way.
Leftover bleach residue is worse for your health, so I rinse thoroughly and scrub with dish soap and a sponge.
Re: #99
I wonder if that alone stops the moss-like black stuff from forming.
Even doing that, I feel like it'd still turn up if you cleaned it with a bottle-spout brush.
Pour it into something else, or drink it waterfall-style, but avoid drinking straight from the spout.
I've been drinking without letting my mouth touch it for years now.
Because of that, no suspicious clumps form inside even after days go by.
Strictly speaking, airborne bacteria and mold probably still get in,
but out of the hundreds of bottles I've gone through doing this,
I've only once found a hazy bit of mold —
and that was one I'd forgotten about and left sitting for a long time.
✕ Kitchen Haiter
○ Soak in OxiClean
This is exactly why I won't buy ones where the mouthpiece is a separate part.
I only go for ones with a plain tube-shaped opening,
where the packing either comes off or is bonded on as one piece,
so I don't have to take it apart every time.
Credit to Thermos — their dishwasher-safe model comes apart easily.
I want to use mine in winter too and drink out of the cup lid,
so wouldn't that rule out the cup type?
Though I think this issue applies to the direct-drink type as well.
Thermos is out of the question!
That puffy silicone part sticking out drives me crazy!
It has to be something simple like a Zojirushi.
Re: #133
Couldn't you just carry a small separate cup?
Inbound tourists will laugh at you —
like, 'Going on a picnic or something?' lol
If you're scared of a stroke or heart attack, carry a water bottle.
Background and Key Points of This Discussion
Slime in a water bottle is distinct from pigment stains like tea discoloration — it forms when bacteria and biofilm grow by feeding on the moisture and sugars left in gaps around the packing and spout. In the thread, posters repeatedly noted that stainless steel bottles can’t handle chlorine bleach (like Haiter) but can handle oxygen bleach (like OxiClean). There were also points that barley tea, being nutrient-rich, spoils easily at room temperature, and that mineral water — unlike chlorine-treated tap water — lets bacteria multiply more readily; however, this isn’t a problem unique to water bottles so much as one tied to how well the beverage itself keeps, and should be read as distinct from structural issues with the bottle (packing that’s hard to take apart, narrow direct-drink spouts). Running it through a dishwasher isn’t a cure-all either — taking the parts apart and washing them individually remains the basic approach, which lines up with what the original article says.
*This article is compiled as an excerpt and summary from the 5ch (News Speed+) thread “My water bottle gets ‘slimy’ even though I think I’m washing it properly — we asked an infection-control expert what causes that ‘slime’ and what care you should actually be doing“.
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