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By: Andrew Forrest - July 2025
Staying hydrated is essential on any hike, but what's the best way to carry your water? Hikers often debate hydration bladders versus water bottles - essentially, using a flexible water reservoir (hydration bladder) with a drinking pipe, or sticking to traditional water bottles.
In this guide, we'll examine the advantages and disadvantages of hydration bladders (also known as hydration reservoirs or water bladders) compared to regular water bottles, to help you determine which option best suits your hiking style.
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A hydration bladder is a soft, flexible plastic reservoir designed to store water, usually placed inside a special sleeve of your backpack called a hydration pack, or just in the body of the backpack itself. It features a long tube ending in a bite valve, a soft nozzle that opens when you bite, squeeze, turn, or pull an opening mechanism, allowing you to drink through the tube.
A 3-litre Osprey Hydraulics water reservoir
This setup enables hands-free drinking while on the move. Suck on the open valve, which works like a straw, and sip without stopping or removing your water bottle. Hydration bladders come in various sizes, typically holding 1 to 3 litres, making them ideal for long hikes where refilling might be difficult.
The end-on view of a bite value
Well-known brands include CamelBak, Osprey, Platypus, and HydraPak. Many modern hiking backpacks are designed to be hydration-compatible, with an inner sleeve and a port for the tube.
In simple terms, a hydration bladder is a large, flexible water pouch in your backpack that features a drinking hose, allowing you to sip water continuously while hiking without needing to remove your pack or unscrew a cap.
Everyone likely knows what a water bottle is, but for those unfamiliar, it's a basic container - rigid or semi-rigid - designed to hold your drink. For hiking, popular options include sturdy plastic bottles, aluminium or stainless steel ones (sometimes insulated to maintain temperature, either cold or hot), or collapsible bottles. There is no learning curve; even a child knows how to drink from a bottle.
A metal and a plastic water bottle
Many hiking backpacks feature side pockets or bottle holders for easy access; otherwise, people store their bottles inside their backpacks. Drinking from a water bottle involves removing it from the pocket and tipping it up to drink. They are simple to use. They come in various sizes, such as 0.5 L, 1 L, or 2 L, and you can carry multiple if needed. Filling, cleaning, and checking the water level is easy; usually, you can see or feel how much water remains at a glance, with many bottles having volume markers.
A wide mouthed stainless steel, insulated Hydro Flask
A water bottle is the regular bottle you know - it could be a reusable plastic bottle, a metal bottle, or a flask/insulated metal container. You have to pull it out to drink, but it's simple to use and doesn't require any special setup.
Let's analyse the advantages and disadvantages of using a hydration bladder for hiking.
The most significant advantage is convenience. You can sip water through the hose without stopping or even slowing down. This is ideal for maintaining your rhythm while out on your walk. There is no need to pause, remove your pack, or feel around for a bottle. It's especially beneficial for climbers, trail runners, or anyone who needs to keep their hands free while moving.
Since it's easy to drink from, many hikers prefer using a bladder to drink more frequently than with a bottle. With the tube constantly in sight, it serves as a reminder to drink. Many hikers I walk with who carry bottles tend to take them out at the top of a climb rather than sipping steadily along the way. Taking small, frequent sips helps maintain hydration and prevents the sensation of sloshing in the stomach after drinking a large amount. Continuous sipping can help minimise the risk of dehydration before thirst even arises.
As the hydration tube and bike valve are attached to the shoulder strap of a rucksack, they are always there as a reminder to the hiker to drink
Hydration bladders typically hold two to three litres of water in a single reservoir, which is more than most individual water bottles. Carrying this amount of water in a bladder can be more efficient and stable than carrying multiple bottles.
The bladder sits flat in your backpack, often in a specially designed hydration pouch, distributing weight evenly against your back for better balance. As you drink, the bladder collapses, so there's no sloshing, and it takes up less space over time.
When empty, a hydration bladder is very compact. Unless it has a solid back, you can roll or fold it up, and even if it does, an empty hydration bladder remains very thin. It doesn't take up much space when the water is gone. In contrast, an empty rigid bottle still occupies the same volume.
The very thin, empty 3-litre water reservoir
Inside your pack, the water in the bladder is protected from direct sunlight, so it may stay cooler longer on a hot day, at least until your body heat warms it slightly. The first sip from the tube may be warm if it's in the sun, but the rest remains relatively cool in your pack. With a bottle in a side pocket, the sun can heat it more quickly.
That said, many people now use insulated metal water bottles that can keep water cool for extended periods. Whichever method is used, a good tip is to add ice cubes to your water before setting off on hot days to help keep the water cooler for a more extended period.
With a hydration pack, if positioned correctly, all the weight of the water is on your back, not swinging in your hands or pulling down on one side as it can in a side pocket. This can feel more comfortable and let you use trekking poles or scramble with your hands free.
The hydration slot on a Osprey Talon 33 rucksack
Bladders require more effort to clean properly than bottles. After hiking, you can't just forget about it. You need to rinse it out, possibly scrub inside, and crucially, dry it thoroughly. The inside of the bladder, especially the long tube, can develop mould or bacteria if not cleaned and dried thoroughly.
This maintenance can be fiddly. For a comprehensive guide on cleaning and caring for hydration bladders, refer to our Hydration Bladder Guide.
Refilling a bladder can mean unpacking your rucksack to pull the bladder out, especially if it sits in an internal sleeve. It's more fiddly than refilling a bottle. You often have to disconnect the hose, fill the bladder at a stream or tap, and then return it to your pack.
Always remember that if you are drinking stream water, water from a lake or any water that you are unsure is uncontaminated, make sure to use a water filter before drinking it.
Some newer designs feature quick-connect hoses or wide openings, making it easier; however, it's still not as quick as dunking a bottle into a stream or using a water filter directly into a bottle. That said, hydration packs are generally larger than water bottles and need refilling less often.
Having your hydration bladder in your backpack makes it hard to see how much water remains. You might sip regularly and then suddenly find it's empty, often at a very inconvenient moment.
As long as it is on the outside of your backpack, with a clear water bottle, you can glance and see how much water you have remaining. If it is in your backpack, you knew how much water was in it when you put it there, so that will not have changed.
To check a bladder, stop and open your pack or lift it to feel the weight. This uncertainty can make water management more difficult. That said, after using hydration reservoirs for a while, you become roughly aware of how much you're drinking and how much is left.
A hydration bladder is fundamentally a large plastic water container, and leaks can happen. A loose cap or an improper seal can cause flooding inside your pack. Bite valves might drip if the shutoff switch, if present, isn't closed. In the worst cases, a bladder could puncture or a tube might disconnect, potentially soaking your gear.
High-quality bladders are generally durable and have reliable closure mechanisms. However, the consequences of a leak are serious, as everything in your bag can become wet. That said, I have been using hydration bladders for over 20 years, and I have yet to have one leak inside my backpack.
To protect against a leaky bladder or heavy rain, I always have a dry bag inside my rucksack, effectively as a rucksack liner, that contains all its contents except the hydration bladder. Dry bags are a vital part of my essential hiking kit.
Water is heavy, weighing 1 kilogram per litre, which is much more than your bladder or water bottle. A 3-litre bladder adds 3 kg to your back. Although the weight is balanced, it remains a load.
Carrying three litres in bottles is just as heavy. However, avoid overfilling a large bladder if you don't need that much water, as you are then carrying unnecessary weight. After hiking for a while, you generally become accustomed to knowing how much water your body needs during a walk.
In freezing temperatures, the water in the thin tube of a hydration bladder can freeze solid quickly, potentially cutting off your supply. An insulated tube cover may prevent or delay this.
The thin exposed hose on a water bladder, that could ice up in freezing weather
In contrast, water bottles, especially if kept inside your coat or in an insulated sleeve, tend to fare better in winter. I have walked in freezing temperatures in winter with hydration packs and have not had an issue with this. The regular sipping and moving water along the tube helps keep it from freezing.
Additionally, if you're wearing thick gloves in winter, handling bite valves and opening mechanisms can be somewhat challenging.
A hydration reservoir is designed primarily for storing drinking water or cold beverages. You shouldn't put hot drinks, such as tea, coffee, or soup, in it, as the heat can damage the plastic and cause scalding. Additionally, avoid pouring boiling water into it.
You can put electrolytes and flavoured drinks in it, but if you don't wash the bladder immediately after use, it can become stained with the colour of your drink. With a bladder, you have only one drink option.
With water bottles, you could carry water in one, water with electrolytes in another, and coffee in yet another. There are many electrolytes available to add to your water, but the ones I have used for many years with no stomach issues are the Science In Sport Hydro Electrolyte Tablets.
Now, let's examine the traditional water bottle method for carrying your hiking hydration, along with its advantages and disadvantages.
Water bottles are simple to refill from any source, open or unscrew the lid and pour in - no need to unpack anything. Most have a wide mouth, making them easy to clean with a brush or just soap and water. Many plastic and metal bottles are dishwasher-safe, so there are no long hoses or corners for dirt and germs to hide in, and maintenance remains straightforward.
The wide opening of an insulated metal water bottle that is easy to fill
It's straightforward to monitor your water supply with bottles. If the bottle is transparent or translucent, it allows you to see the water level. Even with opaque or metal bottles and flasks, you can feel the weight or open the lid to check. This makes it easier to ration your water on a long hike because it provides a visual cue.
The water level is clearly visible in this plastic water bottle
A high-quality water bottle, especially a single-piece design made of solid plastic or metal, is durable. You can drop it, bump it, or even step on it in many cases without it breaking or bursting. There's no hose or bite valve that could leak. The caps create a secure seal as long as you screw them on properly. I have found, however, that some cheaper plastic bottles are prone to cracking over time.
The wide mouth Hydro Flask with Flex Cap
Water bottles are more versatile than hydration bladders. You can pour hot drinks into a suitably insulated bottle allowing you to enjoy hot coffee or soup on a cold winter walk.
I know a couple of people who use a plastic bottle as a hot-water bottle in their sleeping bag at night by filling it with hot water to keep
warm. I would be very cautious of leaks if I did that, and the bottle could become uncomfortable. I would rather stay warm with a proven
sleeping system of a
sleeping mat,
a sleeping bag, and a
sleeping bag liner.
If you take more than one bottle with you, you can pick and choose your drinks. You could have water in one, soup in another, and an electrolyte drink in a third.
In freezing weather, store bottles in your rucksack to stop the liquid inside from freezing. There are no thin tubes that might freeze, unlike hydration bladders. Some metal bottles are insulated, keeping your water from freezing and hot drinks hot. If you're not wearing a rucksack, tuck the bottle into your coat pocket, and your body heat should prevent it from freezing.
The wide mouth insulated stainless steel Hydro Flask with the straw lid
In hot weather, you can pack a bottle with ice or use a double-walled insulated bottle to keep water cold. There are even filter attachments, such as the very popular Sawyer Squeeze or LifeStraw filters, that screw onto bottle mouths for easy water purification on the go. These are very useful if you need to treat stream water for drinking while you're out on your walk.
If you hike in a group, it's easy to share water from a bottle. With a bladder's mouthpiece, sharing isn't very hygienic, and pouring from a floppy bladder is awkward. Bottles are more social!
You don't need a backpack to carry bottles. Any bag that can hold your gear can fit a water bottle. Additionally, reusing a plastic bottle, such as a water or soda bottle from the supermarket, costs almost nothing. However, they are much flimsier bottles that crack, split, and leak more than purpose-made water bottles.
For hiking, purchase a purpose-built water bottle instead of reusing a supermarket bottle. There are many inexpensive water bottles available that are cheaper than hydration bladders; however, good-quality or insulated bottles and flasks can cost as much as a hydration bladder.
One potential disadvantage of using a water bottle is its inconvenience. To take a drink, you usually have to stop walking, take out the bottle, unscrew the cap, drink, then close it and put it away. If you are walking with friends, they can get your water bottle out without you having to take your backpack off, but if you are walking alone, this often means removing your rucksack as well.
This interrupts your flow, especially on difficult terrain where you may need to use your hands for balance or when using hiking poles.
I can usually reach around and grab a bottle from a side pocket while walking, but I always find it tricky to put it back.
Many hikers often avoid drinking enough because it is inconvenient. They frequently wait until a rest stop or the next peak, which could lead to mild dehydration if they are not cautious. Additionally, often, what is out of sight is out of mind. Having a tube visible near your chest from a hydration pack serves as a constant reminder to keep sipping.
Water is heavy - 1 litre weighs 1 kilogram. Bottles and hydration packs all have some weight, but that is usually easily outweighed by the water weight, roughly in the ratio of 8:1.
A rigid bottle has its own weight, as does a hydration pack. Generally, a 3-litre hydration pack weighs less than three one-litre water bottles. In addition to some extra weight, there is also more volume.
A 3-litre Osprey hydration bladder and three water bottles carrying the equivalent amount of water
A litre of water occupies the same volume regardless of what it is being carried in. However, once the water has been drunk, the water bottle still occupies the same space. In contrast, the hydration pack now only occupies a fraction of its original volume.
The 3-litre hydration pack now empty and flat, compared the the volume that the three water bottles still take up
You can't drink from a bottle without using at least one hand. For routine hiking, this is fine, but if you're trail running or scrambling up rocks, reaching for a bottle can be inconvenient or unsafe. That's where you'd miss the bladder's hose, as you don't have to stop to take the backpack off to access the water.
It's minor, but bottles can be misplaced or accidentally dropped. Many walkers have had a water bottle roll down a hill or 'forgotten' one at a rest stop - I know that from the amount that I have found and picked up on hills! A hydration bladder, being secured inside your pack, can't be dropped if it is fixed inside your rucksack. I must admit, I've never lost a bottle walking, but I have when jogging - it must be all the bouncing up and down!
While almost all backpacks have spots for bottles, a few ultralight packs prioritise bladder use and have no or few side pockets that can be used for water bottles. If your side pockets are small or hard to reach, using bottles becomes more troublesome. Most traditional packs accommodate both, though.
It's not an either/or scenario for many hikers - you can combine both. I know I drink a lot more than most people, and I don't mind carrying the additional water weight, so my preference is a 3-litre bladder, which I fill or partially fill depending on the length of the walk, along with a couple of water bottles.
The author's choice of hydration pack and two water bottles for long walks where no water source will be passed
In one bottle, I have electrolytes, so I don't discolour my bladder, which I have done many times in the past. The other is generally water, in case the bladder runs out.
It is generally rare for me to stop during walks, but if I'm walking with friends and a lunch stop is likely, I usually take a stainless-steel insulated bottle with some coffee or soup inside.
Having both can be useful for situations where pouring water is necessary, such as rinsing a wound or sharing water with your dog. Possessing both offers flexibility: the bladder keeps you hydrated on the move, while the bottle provides additional uses.
The choice is yours. Consider the conditions of your hike and your habits. If you value convenience and constant hydration, a bladder may be the best option. If you prefer simplicity and versatility, bottles may be the better choice. Many hikers eventually develop a system using either or both to suit their needs best.
There's no single 'right' answer in the hydration bladder versus water bottle debate; both have their merits. Hydration bladders offer unbeatable convenience and can encourage you to drink more regularly. On the other hand, water bottles provide simplicity, reliability, and multi-use versatility. Remember, you can always use both: for instance, carry a bladder for convenient sips and a bottle for backup or mixing drinks.
Regardless of the option you choose, the primary goal is to stay hydrated. Dehydration can quickly turn an enjoyable walk into a miserable experience, so be sure to have enough water and drink regularly.
Happy hiking, and cheers to staying well-hydrated on the hills!
Neither is universally better; it depends on your personal preference and the specific needs of your hiking trip. Hydration bladders let you sip without stopping, whereas water bottles are simpler to fill and monitor, so each has its place while hiking.
Yes, hydration bladders offer some advantages over water bottles. You can sip water hands-free without pausing your hike, and they typically hold more water than a standard bottle, which is excellent for longer adventures.
Yes, refilling a bladder is usually a bit more of a hassle. You often have to dig it out of your pack, and where you fill can be harder to hold open, whereas bottles are straightforward to dunk in a stream or pour water into. That said, many better hydration packs come with quick-release clips and have reinforced plastic at the filling point.
Yes. Hydration bladders require more maintenance and regular cleaning than a simple water bottle. You need to scrub and dry them thoroughly to prevent mould, and access isn't always straightforward. In comparison, bottles are much easier to rinse and wash out.
No, they don't leak often if maintained properly. Modern bladders are fairly durable, but they can occasionally fail due to punctures or loose connections. Regular inspections and securing the bladder in your pack are recommended. To prevent the rest of your pack from getting wet, use a drybag as a liner inside your rucksack.
Yes, water bottles generally perform better in freezing conditions. A bladder's tube can freeze in icy weather, while a bottle kept warm in your backpack will keep water from freezing despite the cold. That said, there are ways to circumvent this, as outlined above.
No, you should not pour hot drinks into a hydration bladder. Hot liquids can damage the bladder material and cause leaks, so it's safer to use a durable, insulated bottle for coffee or tea.
Ideally, clean it after every hike, especially if you've put anything other than water in it.
Empty, rinse, and clean the bladder after each use. Then, allow it to air dry thoroughly to prevent mould or bacterial growth. Additionally, always use clean water and avoid leaving water sitting inside for days. Regular cleaning and proper storage will keep your bladder fresh and safe. I often pop mine in the freezer once cleaned, to ensure anything still lurking in there is killed off.
Yes, a good hydration bladder typically costs more than a basic water bottle. Some of the quality water bottles and stainless-steel insulated flasks can cost as much as hydration bladders. If you value the added convenience of hands-free drinking on your hikes, then they are worth the cost.
July 2025
