Just learn how to clean them and clean them. There is no magic bottle that doesn't.

The only thing that ever comes in contact with my water bottle is water. It is always spotless.

You are contaminating it with your mouth when you drink from it. If you put sugary stuff in there, you are basically carrying a petri around with you and asking why its growing stuff.

32oz wide mouth Nalgene for me. I have 3 and cycle them every 2 days. Dishwasher when I run it and bottle brush once a week. Never a hint of anything.

Anything that's wet all the time is going to grow mold or algae or whatever.

Whether you rinse or scrub, if you just shake off the drips or even towel it off before you fill it up again it's going to get gross.

It needs to spend a significant amount of time completely dry.

The solution is to have 2 bottles and switch them every few days.

I would just not care about the biofilm and wash it regularly. If you fill the bottle from a clean source and it doesnt smell or taste strange, the water should be fine for consumption.

You know your fresh water pipes also have biofilms in them? If it isnt contaminated, the microorganisms there are harmless. So if you get clean water from the pipes and your mouth has a healthy microbiome, where should potentially harmful microorganisms come from?

Only in rare amounts from the environment when you open the bottle. For that to create a buildup will take time. If you properly wash your bottle like once a week you should be fine.

No bottle will stay clean if you dont wash it from time to time.

Yeti wide mouth because it's easy to clean. I just flush it with hot tap water and a drop of Dawn, let it sit for a few minutes, then hold my hand over the mouth and shake. Rinse thoroughly, then dry right side up so condensation doesn't build up inside. The part to really pay attention to is the mouthpiece, but that is quickly cleaned with some soapy water and a rag.

Also, DON'T use your dishes rag/sponge on your water bottles, as it always has residual dish gunk (no matter how many times you rinse it) that will actually make your water bottle dirtier. Keep a separate rag for washing drinking bottles and wring it properly when you're done.

Mold = dust/residues + dampness. Clean your bottles, and keep them dry when out of use - you can keep water filled bottles pretty long in the fridge.

My 4 year old bottles stay filled in the fridge; when a bottle travels with me, coming home i wash them with my bottle brush and a small amount of dish soap and either fill them right back up and put them in the fridge again, or i keep the cap off and let them dry thoroughly putting them upside down so droplets can get out. Anything else is just an invitation for mold.

The solution to your problem is not to buy one specific bottle. The solution is to have two separate water bottles, so that you can swap and clean them on your own time.

you can clean them daily, they get black spots

Daily?! I clean mine weekly and I put coffee and milk in them. I drink my coffee by lunch and rinse them out 3x. I turn them upside down and air dry the 2nd half of the day. They're dried by end of day. Do that 5x a week. Wash on the weekends.

get a non-plastic bottle. plastic is notorious for harboring bacteria, and mold, because they are prone to microscope crevices from forming. probably a metal one. you might want to use soap and hot water for metal containers.

FWIW water grows less mould than water with sugar/flavor/etc.

Assuming USA, kleen kanteen, with a simple screw-off cap. Or yeti with those slider caps. Personally as a desk worker my water jug has no cap.

For cleaning, soaking for 20 min or so with hot water and something like unscented oxyclean, powder brewery wash, or a bit of dishwasher powder works very well at removing organic matter - for stainless and glass.

I've had good luck with kleen kanteen. Stainless steel with a steel screw in top. No gaskets.

I know what you mean about the moldy gaskets, I've had that problem with insulated coffee mugs.

You're probably going to have the easiest time just cleaning them periodically.

If you want to have something that's intrinsically antifungal, instead of stainless steel, you could get a copper-alloy water bottle, like bronze or brass.

https://en.wikipedia.org/wiki/Antimicrobial_copper-alloy_touch_surfaces

Antimicrobial copper-alloy touch surfaces can prevent frequently touched surfaces from serving as reservoirs for the spread of pathogenic microbes. This is especially true in healthcare facilities, where harmful viruses, bacteria, and fungi colonize and persist on doorknobs, push plates, handrails, tray tables, tap (faucet) handles, IV poles, HVAC systems, and other equipment.[1] These microbes can sometimes survive on surfaces for more than 30 days.

I wouldn't bet on it stopping growth on the gasket, though.

It looks like this claims to be copper (which if correct, I would think would be really prone to denting):

https://www.amazon.com/Adonai-Hardware-Hammered-Copper-Bottle/dp/B09MZ9VYJS

This vacuum flask says that it has a copper internal lining:

https://www.amazon.com/OUTSIDER-Stainless-Vacuum-Insulated-Bottle-Thermos/dp/B0BX7C1MDK

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.

I use a stainless steel insulated bottle and I clean it with Polydent tablets, like for cleaning dentures. It works incredibly well.

The kind that is cleaned properly.

Guaranteed to keep your water cool.

I wish I knew. Scouring a metal bottle by using a bottle brush with a little water and rock salt or baking soda can help de-scum the films that lead to mold.

Historically, these are the consensus fave in reusable bottles:

https://en.wikipedia.org/wiki/Calabash

I have about 10 protein/gym shakers, that I use for shakes (obviously) but also just water. I have so many because they will sometimes come free when i order supplements - but they can be bought for a few dollars. I rotate them daily and just run them through the dish washer. Because they're wide and the lid comes off they are super easy to wash and dry.

I'll normally get a couple years out of them before they need replacing.

Reading other replies, I find it interesting. I use a manna water bottle (big 128fl oz one) and typically drink about half a day. I normally can let it be for quite awhile (a few weeks I’d say) before feeling like I should clean it.

flip top stainless growler, get a bunch of extra gaskets and rotate them. I put them in the dishwasher in the cutlery tray that has a lid to keep things from flying out, then boil them submerged under a stainless trivet to get any smells out.

the bottles I just use soap and a brush and if it smells like anything after that then PBW or oxy powder.

bottles with straws, slide seals, the other type of flip lid, hollow lids, etc will inevitably have unwashable areas that will get nasty.

runner up is this. they fit the same opening

it looks like they dont sell the growler flip any more but I bought several for my klean kanteen knockoff (unintentional kkk) standard size bottles too.

Tape some bubblewrap around a mason jar taps forhead

I'm a huge fan of glass bottles because of their ease of cleaning and resilience to getting funky. The lid is the only place you have to be careful of, but that's usually a lot easier to be mindful of

I really like my owala water bottle. I don't think there's any hidey-mouldy places, and it's water-tight. I also appreciate the dual straw&chug mouthpiece. Pretty clever imo.

I like wide mouth bottles that match the diameter of the rest of the bottle, because they are the easiest to clean. You can even just toss them in the dishwasher depending in the material.

I also try to only buy titanium bottles since they last a lot longer than stainless steel. Some brands are too expensive but ive gotten lucky in the past with no name brands.

I've had a Hydroflask wide mouth for about 7 or 8 years now and I've never had any mold issues with it. At least once a week after cleaning with soap, I pour in maybe half a cup of white vinegar, put the cap on, and shake it around, then leave it for about 15 minutes or so, then rinse it out fully. Never had any issues with mold on the bottle or in the cap. I use a bottle brush I got from the baby section of the supermarket to clean it out.

Just clean them. I soak mine in hot bleach water for a few hours, then rinse thoroughly 🤷‍♀️

The Contigo Cortland chill. I love this bottle so much if I lose it I buy another. I've been using this bottle for at least 6 years now.

Because it's a button spout it's very good for air sipping (water falling). Since I don't put my mouth on it, there is less chance of bacteria developing in the bottle and lid.

The Lid folds open on the inside which makes it easy to clean by hand.

I see they have new filtered variants, I haven't tried those yet.

I bought a metal tumbler for this exact reason, easier to clean and longer lasting.

I just use those protein blender bottles as a water bottle and they work great. They're high capacity, simple, and fit well into cup holders. There aren't any gaskets or crevices for mold to grow (plus they're clear and light kills mold). I have like 4-5 of them that I cycle through.

I have a Bubba water "bottle" I've been using daily since 2019. No mold, no issues. https://www.amazon.com/dp/B079B962YQ Non-affiliate link.

I have a stainless steel Nalgene bottle that I only use for water. It does have a plastic cap that is a bit unsatisfying. But, I haven't noticed any mould issues and it's perfectly ok to clean the metal part with boiling water or with bleach.

Using 2 bottles atm. Both from LTT (youtuber merch).
After use I clean them witg fresh water and dry them over night in a reverse position.
So far it was sufficient to not develop any smell. On ocassion I'll clean it with dish soap.

Well I use a nalgene and a Kleen Kanteen. Both have that standard open mouth design. You're gonna need to clean the caps and O-rings but they're pretty good

Put them in the dishwasher after every use. If it is not dishwasher safe, throw it away and get one that is.

They actually had a special on drinking bottles recently and I was thinking about buying one. Then they had a report on TV about such non-dishwasher-safe bottles, and that you simply don't get them clean with washing them by hand. They had some nice pics of such bottles building up things in nooks and crevices. Gave up on that special offer, as they were not dishwasher safe.

Gaskets are consumables, whatever bottle you get, make sure you can source additional gaskets.

Never had mold in my Camelbak chute

Youtuber "Miranda Goes Outside" just came out with a bottle that's supposed to resemble a Smart Water bottle in form-factor but have the entire top unscrew ( in addition to the narrow standard bottle cap) for easy cleaning.

I just use a plastic volvic bottle. They're usually fine for a couple of weeks. I guess it would depend what's in your local water supply.

I had one that had little domes to form the threads and it cleaned easier.

Nalgene and a bottle brush.

I’ve used a single Sigg traveler bottle for ages, but I’ve had mold buildup on the cap seal. Luckily Sigg has the caps sold as spare parts, so I’ve only had to replace the cap a couple of times during all this time. But it’s been near 15 years I think now, lining intact and all. It’s got a bunch of dents from falling on hikes, sometimes down from pretty high cliffs, but I feel it only adds to its attitude sort of.

Not sure if I’d go for a Sigg today, I have stainless steel in my sights if this one ever proves ready for retirement, but Id definitely choose one that has either replaceable seals and seals sold as spare parts, or at least sells new caps as spare parts. And I’d for sure go with something similarly robust that can handle drops and getting banged around.

The cap design on the Sigg is pretty unbeatable though. It’s so natural for a finger when opening or closing and keeping the cap while drinking, but it also fits all sizes of carabiners or similar, so it’s just so handy to keep around on house but especially on hikes. I’m spoiled thanks to that, so I think there’s a high standard for whatever I’d choose next.

But I can really recommend the aluminum Sigg traveler. Today it has a lot more actually enticing competition, but it’s a classic choice at least around here in Northern Europe.

Edit: Worth noting; Siggs prior to 2008 had BPA in the lining. Mine has a yellow tint in the lining, which is the telltale sign of the BPA-free, safe one. Today, only the aluminium bottles are manufactured in Switzerland, the others are in China (which I think has been thanks to some brand-leeching Chinese acquisition at some point)

Edit2: I also have a lot of old military surplus water bottles from around Europe (similar form factor) simply because both my few-days-bag and longer hiking rig have MOLLE all over the surface, and the old ALICE (us standard from I think around 1970) and MOLLE (or similar, today almost everything in terms of military surplus has something that fits into it) pouches for the water bottles of that certain shape can be had for extremely cheap, and they are so robust in keeping them in place thanks both to the bottle shape and the MOLLE in general, and it’s so flexible.

I mostly use these to carry extra water as plan B but especially for boiling for food or coffee etc. all of them have a certain funky smell that never disappears, but I’ve tested them all by keeping plain water in them for a week or more, then pouring out and seeing how it looks to naked eye, and how it tastes. The smell on some of them can get into the water a little bit, but all taste normal and so far I’ve not got any problems from using them. I would assume the military of all institutions would take care to make these things valid for long term and active use, since, you know, water is pretty much the main driving force in ensuring troops can keep going. But because of the smell I tend not to go for them as the main bottle, ever.

I had a Zojiirushi in the past too. I agree, it takes too much effort to clean. I now use a wide mouth bottle that just has a screw top lid, no straw or drinking apparatus besides the large open mouth. No gaskets or anything else. It's only two surfaces to clean and requires no disassembly, other than taking the lid off. It's much easier to keep clean.

The brand doesn't matter. Just get a wide mouthed metal bottle of whatever cheap brand is around. None of them have engineered a new alloy that makes their bottles better or anything. Just make sure it's double-hulled if insulation is important, which most are.