What is a Hydration Bladder? » Buyer’s Guide
03/2025
Every type of outdoor activity requires different equipment. However, there’s one key aspect that’s central to all of them: a good supply of water. Because whatever you get up to when you’re out and about, staying hydrated is key. With a hydration bladder, your next refreshing sip is only one tiny move of the head away. In this guide, we’ll tell you exactly how to pick out the right hydration bladder for your needs, how to correctly use it, and how to properly care for it.
What are hydration bladders and packs?
First things first: Hydration bladders ↗ are flexible, reusable water containers allowing you to drink without using your hands. They consist of:
a water container, which is usually made from sturdy and BPA-free materials
a tube that connects the container to your mouth
a valve from which you can drink
The container is filled with water and stored in your backpack ↗, directly lying against your back.
The drinking tube runs from the backpack over your shoulder, where the drinking valve allows you to access your water supply. Hydration bladders are usually used for outdoor sporting activities which require a lot of hydration throughout, or where it’s not always that easy to take a water break. Thanks to the tube that directly leads to your mouth, you don’t have to stop whatever you're doing to take a sip – allowing you to stay hydrated on-the-go.
How do I choose the right hydration bladder?
Whether trail running or climbing: The right water supply is key to make sure your energy levels can keep up with your goals and ambitions. So before making a purchase, make sure you know exactly what types of bladders are available to pick the one that works best for your own individual requirements. Here’s what you need to look out for:
Capacity: Choose the capacity of your hydration bladder based on your needs, as well as the duration of your planned route. If it’s a short trip, you’ll usually be fine with 1,5 liters. If you’re setting out on a longer tour or have your sights on more demanding physical activities, models with 2,5 liters capacity tend to be a good choice. Also, bear in mind that you’ll need more water on hot days. So when making a decision, always factor in that while a bigger bladder will weigh more, it also means you can stay hydrated for longer without needing to make time for a refill.
Closing mechanism: Generally, there are two types of closing mechanisms on hydration bladders: a round screw cap or an opening similar to a zipper that runs along the full width of the pack. While the screw cap may be more convenient when refilling the hydration bladder, the zipper mechanism makes it much easier to give the bladder a thorough clean. By the way: All our Mammut hydration bladders can be turned inside out to make cleaning and drying your equipment even easier!
Drinking valve: Just like with the closing mechanism, there are also different types of valves available: Bite valves, which open under pressure, sliding valves, and rotary valves. Which type of valve you should choose is usually a matter of personal preference. The key thing is to make sure that the valve is leakproof so you don’t lose your supply along the way. To give you extra peace of mind, our Mammut hydration bladders come with a bite valve AND screw cap to provide double the protection against leakage.
Durability: A high-quality hydration bladder should be made out of a sturdy and durable material which can withstand the strains of frequent use as well as tough conditions. Pay attention to the quality of construction to reduce the likelihood of leakage and damage. Models made of BPA- and PVC-free plastic offer the best in durability – and are perfectly safe to use.
Additional features: Additional features like a removable tube, a grab handle or temperature-resistant material are also product aspects you might want to factor in when making your decision.
The right backpack for your hydration bladder
It’s not just hydration bladders that offer plenty of versatile options: The same goes for backpacks, which are tailor-made for specific types of activities from trail running to mountainbiking. Generally you can fit a hydration bladder into virtually every backpack and every trail running vest ↗. In most cases, there’ll even be a designated compartment for the container, as well as an opening for the tube. As the material of the bladder is flexible, it’ll adapt perfectly to fit the available space in your backpack. Just make sure it’s lying directly against your back, and that there are no sharp items within touching distance to prevent accidental damage to the material. For more useful tips on how to choose the right backpack, check out our guide to how much weight a backpack can hold ↗.
Cleaning guide: How to care for your hydration bladder
Regularly cleaning your hydration bladder not only ensures the best possible level of hygiene, but will also increase its durability. Make sure to rinse your hydration bladder, tube and valve with hot, but not boiling water after every use. If you’re only filling your bladder with water, this type of quick-clean is perfect for in-between uses. Leave all components to dry thoroughly, and store in a dark and dry place. Always keep your hydration bladder away from direct sunlight when leaving it to dry.
If you normally fill your bottle with juice or other types of drinks, as well as after roughly every third use, you should give your hydration bladder a thorough deep-clean. Use warm water and a mild detergent for this. You can also get special cleaning sets with round brushes to help you scrub the container and tube. If you notice excessive limescale deposits, diluted vinegar may just be your best friend: Simply leave all components to soak, then rinse them with water.
Tip: If possible, always turn your hydration bladder inside out when cleaning and drying it. That way, you can ensure every nook and corner will be clean and dry.
Water bottle vs. hydration bladder: Pros and cons at a glance
You’re still undecided if a hydration bladder is the right way to go? It goes without saying that both regular bottles and hydration bladders have their very own pros and cons. The biggest advantage of hydration bladders is obvious: You don’t need your hands to stay hydrated. As you’re always carrying it right against your back and the bladder itself doesn’t really have any real dead weight, you won’t be weighed down even when taking a lot more water with you. The only downside: Cleaning them tends to be more of a hassle, although modern models usually make the whole process a lot more straightforward than you might think.
Water bottles, on the other hand, are easy to use and clean. You can quickly fill and clean them, as well as use them to wash your hands as well if needed. Plus, you’ve always got an eye on your supply levels. The obvious downside: Having to constantly grab, hold and replace a bottle while in the middle of your activities can be a little impractical – and might even make it necessary to interrupt whatever you’re doing. Water bottles also tend to be a lot more chunky and take up a lot more space in your backpack, which can be a bit of an inconvenience especially on long tours.
So which option should you go for? As the saying goes: it depends. While a regular bottle like a soft flask ↗ may be perfect for short routes, hydration bladders are definitely a much better choice for longer trail runs or more intense mountaineering activities. On particularly long tours, it might even make sense to take both and enjoy the best of both worlds – so definitely think about investing in a bottle and hydration bladder if you’re frequently embarking on outdoor adventures.
Ready for action with Mammut’s Top Tips
With your new hydration bladder, you’re all set for your next adventure! On top of that, we’ve collected a host of useful tips and inspiration in our Mammut Stories and Guides ↗ to help you get started – from our ultimate backpacking gear list ↗ to our guide on how to choose trail running shoes ↗. But whatever you’ve got planned, don’t forget the most important thing: Stay hydrated!
