To make iced coffee, I favour a wide-mouthed S’well bottle, because I am super basic, but also because I found the opening is wide enough that I can easily fill it with ice and perch my pour-over brewing device atop it to make a quick Japanese iced coffee. Unfortunately, my bottle—made to hold water—loves to absorb the scent and flavour of the brew, which makes it less than ideal when I fill it with… basically any other liquid. Luckily, I’ve discovered a few different methods to deodorise it, ranging from the simple to the more intense.
Soap and a bottle brush
The dishwasher is right out—HAND WASH ONLY, the bottom of the bottle warns me—but as long as I haven’t let coffee linger for a few days, I can usually get things smelling all right again by giving it a scrub with a bottle brush and some dish soap. I already had a bottle brush lying around because I have small children who like to drink out of weird and hard-to-clean plastic cups, but if you don’t, they aren’t a bad buy—you can also use them for cleaning wine glasses, highball glasses and anything else you drink out of but can’t fit your hand down into.
I can’t always get the water from my kitchen faucet hot enough to clean things effectively, so I’ll use my goose-necked kettle (the same one that helps me craft the aforementioned iced pour-overs) to add a bit of boiling water to any persistently grimy pots or pans. The same method can help get clingy smells out of a metal water bottle, and since the things are made to keep liquids hot as well as cold, you can pour the boiling water in, close the lid, and let them soak for as long as necessary for the heat to do its work—overnight if the timing works out, but a few hours will usually do the trick. Plop in a few drops of dish soap at the same time to boost your cleaning power.
If boiling water doesn’t do it for you, another option is to do an overnight soak with a mixture of white vinegar and hot water. Rise the bottle, fill it about a quarter of the way with white vinegar and top it off with hot water (from the tap is fine, but go for boiling for some extra edge). Secure the lid, give the bottle a shake and let it sit overnight. Rise well before using it the next day. The vinegar smell shouldn’t linger, and and sour coffee odours should be gone.
Baking soda and bleach
My preferred option—because I usually can’t find the white vinegar—is a combination of baking soda and chlorine bleach. If it seems weird to pour bleach into something you’re going to drink out of, I get it, but you only want to use a tiny bit—you want to mix 1/2 teaspoon of bleach and a heaping teaspoon of baking soda in a bowl of water large enough to submerge your water bottle in it, per this earlier Lifehacker story. The benefit to this method is that you can soak the bottle’s lid as well—it’s a good way to clean up inside the ridges and rubber seals—but you’ll want to rise, rise and rinse again when you’re done, because you don’t want to drink bleach. (Or do you? No, you don’t.) If the idea of adding bleach to your water bottle is a step too far, you can also omit it, double the amount of baking soda, and soak overnight.
In this Lifehacker post from 2014, Alan Henry recommends cleaning and sanitizing your reusable water bottle with a denture tablet. I wouldn’t buy them just to try this out myself (baking soda is a lot cheaper, for one thing), but if your local senior citizen has a cache lying around, give it a whirl.