Kind of a rant — I drink water and flavored-water beverages, and I don’t wanna buy 24-packs of water and trust my local municipality to recycle. Maybe they do, maybe they don’t. Either way, it’s not recycle, it’s “reduce, reuse, recycle.” I’ll drink a Gatorade (Zero) and reuse it a few times and then toss it.
But if I want a reusable bottle — there’s one by Aladdin (Thermos) I like, and one by Zojirushi, I’ve bought two of each over the years. Just tossed the Zojirushi. Zojirushi is a Japanese brand, very high quality, but a bit over-engineered. It’s got this rubber gasket and plug that, you can clean them daily, they get black spots. Not sure if it’s mould or what, but it’s kinda gross and I don’t like it. The Aladdin/Thermos one is a bit better, didn’t think there was any mould anywhere until I dropped it, the cap flew out, mould farm inside! Nowhere that touched the beverage so that was nice. But I’m kinda done with both of them. I would rather just waste plastic than risk drinking from a mouldy reusable cup.
Are there reusable bottles that aren’t mould farms?
I’ve been using the same few Hydrocell bottles for years. (They’re a stainless steel vacuum insulated bottle, basically a significantly less expensive Hydroflask knockoff.) I use them mostly for water, but occasionally other drinks like unsweetened tea, sugar free electrolyte drinks, etc.
I have never had a mold problem with these. I just disassemble them and run in the dishwasher every few days. (Before I had a dishwasher, I would wash them with hot water and dish soap, lightly scrub, and air dry.)
This really sounds like a cleaning problem to me. I’d recommend washing water bottles every 3-4 days, and if you use a bottle for anything other than water (especially anything with sugar) wash it that same day.
Mold doesn’t magically grow out of nowhere, it needs “food”, a nutritious medium. This could be sugar in a sugary drink, protein in a protein drink, or just contamination from having been in contact with a mouth too many times without proper cleaning.
Also, the quality of the water you’re putting into the bottle makes a difference too. If you’re filling up at the water cooler at the gym or at work, for example, it could be that the water cooler isn’t being cleaned properly and has mold growing within. That would certainly accelerate things in your bottle.