Have you ever been frustrated with having to stop in the middle of a hike, mountain bike, or trail run to take a water break? What if you could keep moving while staying hydrated all at the same time?
Enter the hydration pack. These backpacks are specifically designed to carry hydration systems that allow you to drink water as you charge up or down the trail. Luckily, there are plenty of different water backpacks for you to choose from, but the endless choices can make picking just one a difficult task.
Thankfully, we’re here to help. Coming up, we’ll look at some of the best hydration packs available on the market today and then walk you through the ins and outs of choosing the one that’s right for you. Let’s get to it!
The 10 Best Hydration Backpacks of 2021: Outdoor Empire Reviews
- Best cheap #1: Osprey Savu
- Best cheap #2: Camelbak HydroBak
- Best for the money #1: CamelBak M.U.L.E.
- Best for the money #2: Platypus Tokul
- Best overall #1: CamelBak Franconia LR
- Best overall #2: Osprey Raptor
- Best for running: Osprey Duro
- Best for hiking: Osprey Manta 36
- Best for mountain biking: Osprey Katari
- Best women’s hydration bag: Platypus Siouxon
|Category||Best running||Best hiking||Best mountain biking|
|Product|| || ||
|Water Capacity||1.5 L||2.5 L||1.5 L|
|Pack Capacity||6 L||36 L||1.5 L|
|Weight||0.45 kg (1 lb)||1.25 kg (2.76 lbs)||0.2 kg (.44 lb)|
|- Lots of gear storage space|
- Comfortable for all-day use
|- Body-hugging harness for comfort
- Blinker light attachment
|Best for||Minimalist trail runners||Longer day hikes||Bikers who don't want to weigh down with extra gear|
|Cost||Check Price||Check Price||Check Price
1. Best Cheap Hydration Bag #1: Osprey Savu
Water Capacity: 2 L
Pack Capacity: 4 L
Weight: 0.36 kg (13 oz.)
The Osprey Savu is a hydration waist pack that’s built for light and fast mountain biking or hiking adventures. Just large enough to carry two one-liter water bottle, the Savu is best for quick jaunts into your backyard mountains.
With two rigid back pockets that can each accommodate one-liter water bottles, the Savu is perfect for people who don’t want to stop to drink water as they move but also don’t like to use a hydration system.
Plus, the angled hipbelt and compressions straps keep the waist pack close to your body as you move, so you won’t feel like it’s pulling you off balance as you ride, run, or hike.
If that wasn’t good enough, the Savu has space for up to four liters of gear and snacks to keep you energized during your adventures. There’s also a place to attach a blinking light, which is great for evening rides and runs, especially on dark streets and trails.
Since it’s a waist pack, the Savu is best for shorter outings where you don’t need lots of gear. Minimalist bikers, hikers, and runners love the Savu for its ease of use and versatility in the mountains.
- Easily customizable to an individual’s needs
- Not much gear storage
- Best for people who use water bottles
2. Best Cheap Hydration Bag #2: Camelbak HydroBak
Water Capacity: 1.5 L
Pack Capacity: 10 L
Weight: 0.15 kg (5 oz.)
If all you want is a hydration pack that can carry water and not much else, you don’t need to look any further than the Camelbak HydroBak. Essentially just a hydration system with a backpack harness, the HydroBak is designed to carry a 1.5-liter hydration system for short, quick runs, bikes, or hikes.
The HydroBak is a minimalist hydration pack that has about enough water for a two-hour bike or hike as a small zippered pocket for car keys and other essentials. Weighing in at only 0.15 kg (5 oz.) without water, the HydroBak is so light, it’s easy to forget you’re carrying it.
This affordable hydration pack comes with Camelbak’s new Crux reservoir, which is designed to provide you with 20% more water per sip for more efficient hydration as you move.
This hydration pack is recommended for people who just need a pack to carry water on short-term hiking, biking, or running adventures, where they don’t need any other gear.
- Incredibly light
- Comfortable fit against the body
- New, more efficient hydration reservoir included
- Can’t carry any gear
3. Best Hydration Bag for the Money #1: CamelBak M.U.L.E.
Water Capacity: 3 L
Pack Capacity: 9 L
Weight: 0.62 kg (1.38 lbs.)
The M.U.L.E. is the ultimate hydration pack for mountain bikers on a budget. One of Camelbak’s best-selling packs, the M.U.L.E. has a narrow profile, which makes it lightweight and easily maneuverable as you speed down beautiful single-track biking trails, even when it’s fully loaded with water and gear.
This pack is large enough to carry nine liters worth of gear and three liters worth of water but manages to maintain a surprisingly light weight.
The back panel of the M.U.L.E. features air channels to help keep you well ventilated as you ride in warm conditions as well as a helmet hook for attaching your noggin protector when you’re not riding. The M.U.L.E. also has plenty of pockets for storing keys, bike maintenance tools, and other necessary gear.
At the end of the day, it’s hard to beat the M.U.L.E.’s amazing combination of quality, light weight, versatility, and good price, which is why it’s a great pack for mountain bikers who need the utmost in functionality from their hydration packs.
- Light and durable
- Carries a good amount of gear and water
- Lots of bike-specific features
- Best used by bikers and not by runners or hikers
4. Best Hydration Bag for the Money #2: Platypus Tokul
Water Capacity: 3 L
Pack Capacity: 5 L
Weight: 0.62 kg (1.38 lbs.)
The Tokul is Platypus’ ultralight hydration pack for quick day hikes and mountain bike rides. Built with Platypus’ RidgeAir back panel made from rigid foam with ventilation channels, the Tokul helps wick away moisture to keep you cool and comfortable as you charge uphill or race down the trail.
This pack comes with Platypus’ three-liter Big Zip hydration system, which is well known for being lightweight, BPA- and taste-free, and easy to fill and clean. The pack itself can carry five liters worth of gear, which is just enough to store your snacks, tools, and spare clothing for a quick outing.
Finally, the Tokul has two webbing straps to carry your bike helmet, as well as reflective panels to make it easier to see you on night rides. There’s also a place to attach a blinker light for those nighttime road biking adventures.
The Tokul is best used by bikers and hikers who need a lot of water but don’t need to carry lots of gear. People who bike or hike in hot and dry environments might find that the Tokul is exactly what they need.
- Lots of water storage
- Great organizing pockets
- Minimal space for storing extra gear
5. Best Hydration Bag Overall #1: CamelBak Franconia LR
Water Capacity: 3 L
Pack Capacity: 24 L
Weight: 1.2 kg (2.65 lbs.)
If you need a hydration pack that can carry water and a decent amount of gear comfortably throughout a day of hiking, look no further than the CamelBak Franconia.
The Franconia is CamelBak’s top-of-the-line backpack and is designed to carry a day’s worth of water, food, gear, and other supplies for a day in the mountains.
The Franconia is a “lumbar” hiking pack, which means it shifts the weight of the water to your hips for added stability and increased mobility. This pack also comes with Osprey’s Air Suspension back panel, which keeps the pack away from your pack for maximum breathability.
In addition to being able to carry a three-liter water reservoir, the Franconia has plenty of space for storing extra gear. The main compartment can hold 24 liters worth of gear, while zippered side pockets on the waist belt are great for storing snacks, compasses, and other readily accessible items.
This pack is great for the day hiking adventurer that likes to venture away from well-trodden paths. With plenty of space for water and gear, the Franconia is a great companion for the most epic of day hiking adventures.
- Lots of water carrying capacity
- Lumbar design is great at distributing weight
- Can carry lots of gear
- Heavier than other packs
- More expensive
6. Best Hydration Bag Overall #2: Osprey Raptor
Water Capacity: 3 L
Pack Capacity: 10 L
Weight: 0.82 kg (1.8 lbs.)
The Osprey Raptor is a 10 liter backpack with an amazing amount of storage space in such a small package. It comes with one of Osprey’s proprietary three-liter hydraulic reservoir, which is designed to reduce the movement of the water inside your pack so you don’t feel it sloshing around as you hike or bike.
The reservoir fits nicely into a zippered sleeve, which is also conveniently positioned for easy access, should you need to refill your water while out and about.
The Raptor has a tube portal that brings the hydration tube to your right size, where it snaps onto the pack’s sternum strap using a magnetic clip. This attachment system makes for super easy access to your water on the go.
Other highlights of this pack include the multiple storage pockets, which make it really easy to organize your gear, and the zippered hip belt, which is great for storing snacks for easy access on the fly.
Plus, the Raptor has a mesh hip belt and back panel, which help reduce sweat build-up, as well as a helmet clip to help you easily transport a bike helmet and a blinker light attachment for nighttime rides.
The Osprey Raptor is a great overall hydration pack that can be used and loved by bikers and hikers alike. It’s got just enough storage space for a day hike or a quick bike ride, so it’s a great companion for close-to-home adventures.
- 3-L hydration pack
- Mesh paneling for better breathability
- Not enough storage space for lots of gear
7. Best Hydration Pack for Running: Osprey Duro
Water Capacity: 1.5 L
Pack Capacity: 6 L
Weight: 0.45 kg (1 lb.)
Trail runners who like to move light and fast over difficult terrain can rejoice with the Osprey Duro. Built specifically for people who just want to carry water and not much else, the Duo is a hydration running vest that can accommodate a 1.5-liter hydration system or two one-liter water bottles.
The built-in pouch for the hydration reservoir keeps the water next to your back to provide a bounce-free carry as you run. The vest itself has a body-hugging fit, which is perfect for people who move quickly but don’t want to feel the water sloshing around behind them.
Plus, the vest is made from mesh and die-cut foam, so it breathes well while also staying comfortable throughout your run.
If hydration reservoirs aren’t really your thing or you need extra water on your run, the Duro can also carry two water bottles inside two pouches that are integrated into the vest’s shoulder straps.
On the shoulder straps, you’ll also find a magnetic attachment point for the hydration system mouthpiece, as well as a small vertical pocket that’s great for stashing car keys or small snacks. Ultimately, the Duro is best for minimalist trail runners and ultramarathoners who want to stay hydrated as they crush miles on the road or in the mountains.
- Can carry lots of water
- Not much storage space for extra gear
- Vest design isn’t for everyone
8. Best Hydration Pack for Hiking: Osprey Manta 36
Water Capacity: 2.5 L
Pack Capacity: 36 L
Weight: 1.25 kg (2.76 lbs.)
If you need a hiking hydration pack that can accompany you on nearly any trail, the Osprey Manta 36 might be for you.
A day hiker’s best friend, the Manta 36 features Osprey’s Anti-Gravity suspension system, which helps distribute the weight of the water and your gear around your body to help reduce uncomfortable stress on your hips or shoulders. The pack’s mesh back panel also helps reduce sweat build up and keep you cool as you hike.
What people love most about this pack is the fantastic amount of gear storage space it provides. With 36 liters of space to fit all of your gear, you won’t need to leave anything behind on your next hike.
The Manta has a main compartment that’s accessed by a zipper on top of the pack and also has a front stretch pocket for storing items that need to be accessible as you move. Two zippered hip belt pockets round out the pack’s storage options and are great places for snacks.
If all of that wasn’t enough, the Manta has a clip for a helmet (should you also want to use it for biking) as well as a trekking pole attachment system for when the terrain calls for a bit of scrambling. Finally, the Manta has an integrated rain cover that can be deployed quickly if the weather turns sour.
The Manta is best used by hikers who like to head out on longer day hikes where they need to bring lots of gear and water. All of the additional features on this pack make it incredibly versatile but do weigh it down a bit, so it’s not ideal for runners and ultralight hikers.
- Lots of gear storage space
- Can carry a lot of water
- Comfortable for all-day use
- Too bulky for running and ultralight hikes
9. Best Hydration Pack for Mountain Biking: Osprey Katari
Water Capacity: 1.5 L
Pack Capacity: 1.5 L
Weight: 0.2 kg (.44 lb.)
The Katari is the ultimate mountain biking hydration pack for bikers who like to ride with nothing but the water on their back. This high-quality pack features a low-profile build with an included 1.5-liter reservoir that sits inside an exterior purpose-built pocket.
The hydration tube connects the reservoir to the mouthpiece, which attaches to the sternum strap using a magnetic clip.
Mountain bikers love how the Katari’s soft-edged harness shapes to the body to provide a comfortable and supportive fit. The pack sits close to the body and contours to the shoulders, which provides lots of stability as you cruise down single-track trails.
There’s also a small stash pocket for storing snacks, car keys, or other small necessities. Plus, the pack has a blinker light attachment for evening rides.
The Katari is a great pack for mountain bikers who don’t want to weigh themselves down with extra gear. If all you need on your ride is some water and a whole lot of stoke, then the Katari might be the hydration pack for you.
- Super light
- Body-hugging harness for comfort
- Blinker light attachment
- Not great for long bike rides
10. Best Women’s Hydration Bag: Platypus Siouxon
Water Capacity: 3.0 L
Pack Capacity: 7 L
Weight: 0.76 kg (1.67 lbs.)
The Platypus Siouxon is a women-specific hydration pack that’s equally at home biking on single-track as it is hiking on high mountain peaks. The Siouxon’s women’s fit has soft-to-the-touch fabrics at all body contact points to help reduce chafing and discomfort as you move.
The pack’s back panel is also sized specifically for a woman’s body and is shaped and angled to be more anatomically comfortable against a woman’s hips, chest, and shoulders.
This pack comes with Platypus’ proprietary 3-liter Big Zip hydration system, which is made with taste-free, BPA-free plastic. The hydration system is super light, has a wide-mouth opening for easy filling and cleaning, and an easy-to-use mouthpiece.
The hydration reservoir fits nicely into a dedicated pocket, which makes it easy to access for refilling or cleaning.
Plus, the Siouxon as an abundance of gear storage space, a helmet carrying system, and a fleece-lined eyewear pocket for storing your sunglasses or goggles when you’re not using them. There are also separate pockets for storing tools, repair kits, snacks, and two dedicated sleeves for securing a shock pump and tire pump for your bike rides.
Finally, the pack has a built-in rain cover that can be quickly deployed when it starts to drizzle. Reflective detailing and an attachment point for a blinker light round out this pack’s impressive list of features. Ultimately, the Siouxon is a great option for any woman that needs to carry a lot of water and a lot of gear on their outdoor adventures.
- Comes with Platypus’ lightweight and easy-to-use reservoir
- Great selection of features
- Can store and organize a lot of gear
- More expensive than other options
Why and When You Need a Hydration Pack
Hydration packs are fantastic pieces of gear for anyone who needs to stay hydrated during adventures but doesn’t have the time to stop and drink out of a water bottle.
These packs are specifically designed to carry hydration systems, which can easily be used as you bike, hike, or run in the mountains, eliminating the need to take time-consuming water breaks. Plus, they’re often quite light and designed to carry water so that it doesn’t bounce around on your back as you move.
Any person who likes to use a hydration system can benefit from a hydration-specific pack, as these packs are designed to accommodate these systems, while also making space for additional features that make life easier in the mountains.
Even if you don’t use a hydration system, many of these packs, especially hydration waist belts, can also accommodate water bottles, which can make it easier for you to drink out of them when you’re on the move.
How to Choose a Hydration Pack
Hydration packs are quite simple pieces of gear, but there’s a lot of thought and planning that goes into choosing just the right one for your needs. Before you head out and purchase that brand-new hydration pack for your adventures, take a moment to consider these important characteristics of water backpacks.
Water Pack Types
In general, there are two main types of hydration packs:
- backpack water pack
- waist belt water pack
The central difference between these types of packs, as you might imagine, is how the pack is worn on your body.
That being said, there are some important advantages and disadvantages to each style that are worth understanding before you commit to a particular model.
Hydration backpacks act much like a standard backpack but come with a hydration system that fits into a purpose-built pouch. These packs offer ample storage space (depending on what size capacity you buy), which is great for those longer day hikes where you want to bring sufficient food, water, and extra layers.
Some companies even make hydration packs that are suitable for overnight use, though this is really just a factor of overall pack size.
Many hydration backpacks are also activity-specific, with some being designed specifically for hiking, running, snowsports, or cycling. Here are the main differences between the different activity-specific packs:
Hiking Hydration Packs
Hiking hydration backs are effectively the same as a standard pack for hiking, but they have a purpose-built pouch to hold the hydration reservoir inside the backpack.
Plus, they’ve got an opening at the top of the bag for the hydration tube to feed through, so you don’t have to walk around with your pack zipper slightly open. Usually, they also have some sort of attachment point for the mouthpiece somewhere on the shoulder strap so the mouthpiece doesn’t dangle by your knees as you hike.
Cycling Hydration Packs
While some cycling hydration packs are great for both road and mountain biking, others are made just for one of the two disciplines. Usually, road cycling hydration packs are designed to be low-profile and lightweight so you can set a new PR on your next ride with friends.
Mountain biking hydration packs also try to be low-profile, but they tend to have a bit more space to accommodate any extra gear you might want to bring with you.
Running Hydration Packs
Running hydration packs come in one of two basic models: the running vest and the running backpack. Running vests are essentially a hydration system that slides into a small, lightweight vest-shaped garment that snugly fits.
These are designed for ultramarathon runners and people who run without needing much more than water and a snack or two. They usually don’t have much space for extra gear. Plus, running vests don’t usually come with a hip belt, which is nice if you’re out on a long run.
Running hydration backpacks, on the other hand, look much like a small hiking day pack, but are designed to be low-profile and lightweight with minimal padding.
Usually, they can only accommodate a hydration reservoir, snacks, and a spare lightweight layer, but that’s often enough for a long trail run. They tend to be a bit heavier than a running vest, but running hydration backpacks are better for people who need to carry extra gear when they’re out running in the hills.
Snowsports Hydration Packs
These hydration packs are designed specifically for people who like to ski and snowboard but want to stay hydrated during their adventures.
The main difference between a snowsports-specific hydration pack and a regular hydration pack is that the snowsports models are usually insulated to help prevent the water from freezing.
This feature also makes snowsports hydration packs useful for anyone looking to hike or run in the colder winter months.
Hydration Waist Pack
If you’re out just for a short jaunt in the hills, you might want to consider choosing a hydration waist pack. As you can probably guess, a hydration waist pack is a small pack carried around the waist.
Usually, they can only accommodate a small water bottle and not much extra gear. That being said, they’re great for light and fast adventures where you don’t need much else but water!
There are two main things to consider when deciding what capacity hydration pack you need: the amount of gear you want to carry and the amount of water you need. The amount of gear you want to carry will directly affect the size hydration pack you’ll want to get.
Often, for a short day hike, most people can get away with using a hydration pack between 10 and 30 liters in capacity. Other activities and longer trips might warrant a larger pack (30+ liters), while others like running and road cycling might require a pack that’s 10 liters or smaller.
When it comes to deciding upon the water-carrying capacity of the pack, you first need to determine how much water you drink on a regular outdoor adventure. From here, you should consider the length of whatever activity you might be doing, as longer days in the mountains usually warrant more water consumption.
You’ll also want to think about the terrain you usually travel in.
If you live somewhere that’s hot and dry, you’ll probably want to carry more water (think three liters) with you as you’re less likely to find it on the trail. People who live in cold, wet environments, might only need a two-liter reservoir, as they’ll be able to replenish their supplies during their adventures.
On the other hand, some runners might only want to carry one liter or less, so as not to feel weighed down on the trail.
Fit is incredibly important when it comes to packs, especially snug running hydration vests. Each pack fits every individual differently, so it’s important to find the one that’s the right size for you.
You can get measured for a backpack by a professional at most outdoor stores, which can be a great starting point if the pack you’re interested in comes in multiple sizes.
Our advice? If the pack doesn’t feel great when you carry it around the store or your home, it won’t feel any better when it’s weighed down with water after 20 miles of running on the trail. Make sure your new hydration pack fits well and feels good before you head outside.
Water Backpack Features
Most hydration packs come with some standard features, which we’ll go over here:
Hydration packs that are designed to hold hydration reservoirs will usually have a purpose-built pouch integrated into the pack along the back panel, which is great for making sure the weight of the water doesn’t shift around as you hike, run, or bike.
These pouches generally have a clip at the top, which is used to hold the hydration reservoir upright and in position as you move. Usually, these pouches can accommodate hydration reservoirs between two and three liters in size, but it’s important to make sure your new pack can carry the amount of water you need.
Somewhere on the top or side of most hydration packs is a small opening that allows the hydration tube to sneak through the backpack fabric and out toward you as you wear the pack.
This opening makes it possible to use a hydration pack without having to keep your backpack slightly unzipped to allow the hydration tube to extend from the bottom of the reservoir to your mouth.
Mouthpiece Attachment System
Most hydration packs also have some sort of attachment system to keep the mouthpiece of the hydration system near your upper body when you’re not using it. Often, this is located on one of the shoulder straps, which makes for a convenient storage spot for the mouthpiece when you’re not actively drinking water.
Top Hydration Pack Brands
There are three top brands in the hydration pack market these days: Camelbak, Platypus, and Osprey. Each brand makes quality hydration pack systems, but each has its own advantages and disadvantages. Here’s what you can expect from each brand:
Camelbak is well known around the world for being one of the first companies to mass produce a hydration system. Born out of a need to drink water without stopping to get out a water bottle, the Camelbak hydration system has developed over time to be incredibly reliable.
Camelbak’s hydration systems are used anywhere there are outdoor enthusiasts, whether they are hikers, bikers, or ultramarathon runners. In fact, both US and foreign militaries use military-specific versions of Camelbaks to ensure that their troops stay hydrated, wherever they might be.
The company is known for having been one of the first to completely remove BPA-containing plastics from their products. Plus, their hydration systems are designed to be taste-free while the bite valve on their mouthpieces is well-known for being virtually leakproof when used properly.
Platypus redefined the world of hydration packs and reservoirs by making them incredibly lightweight. The main difference you’ll see when comparing a Platypus hydration system to a competitor’s is that the vast majority of Platypus reservoirs feature their patented “Big Zip” opening system.
Unlike both Camelbak and Osprey reservoirs, which have large twist-top openings, Platypus reservoirs look like gigantic Ziploc bags with a wide opening that makes them really easy to fill up in a river or stream.
Although their reservoirs have stood the test of time, Platypus is actually quite new to making backpacks. That being said, based on how their hydration systems perform, it’d be hard to expect anything less than the best from a Platypus hydration pack.
Osprey is a famous backpack company that is relatively new to the hydration pack game. Their hydration systems closely resemble Camelbak systems, both in style and function. However, where Osprey really stands apart is in the quality and versatility of their backpacks.
If having a comfortable backpack is the most important thing for you as you look for a hydration pack, then Osprey packs are likely a good choice. They offer a wide range of different styles and models, each specifically designed for a particular outdoor pursuit, whether that be mountain biking or marathon running.
How do you use a hydration pack?
Hydration packs are, thankfully, quite easy to use. They are basically backpacks with a hydration system inside.
Hydration systems consist of a soft-sided “bladder,” which holds the water and sits inside the backpack, a long tube that acts sort of like a giant straw to transport the water to your mouth, and a mouthpiece, which allows you to drink the water.
All one needs to do to use a hydration pack is fill up the reservoir and put it inside the backpack. Then one needs to position the tube and mouthpiece so that they are conveniently placed near one’s mouth for easy drinking.
Finally, one needs to bite down softly on the mouthpiece and suck in on the tube as if it were a straw. Voila! You have water and your thirst is quenched.
How do you clean a hydration pack?
Keeping your hydration pack clean is incredibly important as dirt, bacteria, mold, and mildew can easily build up in a dirty hydration pack. The best advice you can get for cleaning your hydration pack will come directly from the manufacturer, as they know what’s best for their product.
That being said, there are some general guidelines you can follow.
Here are the materials you’ll need to clean your hydration pack:
- Cleaning brushes made for your hydration pack and tube
- Clean dish scrubbing brush
- Reservoir cleaning tablets, baking soda, or bleach
- A drying rack
Cleaning your reservoir isn’t terribly difficult, but it is a process. Here are the steps you should follow for a squeaky-clean hydration pack:
1. Fill your hydration pack with warm water and either one cleaning tablet, 1/4 cup (60 mL) of baking soda, or a few drops of household bleach. Seal the hydration pack and shake it up.
2. Lift the reservoir up above a sink and pinch the tube, squirting a little bit of the cleaning solution into the sink. This helps ensure that all parts of the hydration pack are in contact with the cleaning solution.
3. Set the hydration pack aside and let the cleaning solutions do their job. If you’re using cleaning tablets, this will likely be only about five minutes, but with bleach or baking soda, you’ll want to wait about 20 minutes.
4. Drain the contents of the reservoir into the sink and fill it back up with warm water. Add a few drops of dish soap to the water.
5. Scrub the inside of the reservoir with a clean dish scrubbing brush and use a hydration-pack-specific brush to scrub the inside of the tube.
6. Thoroughly rinse everything out with clean water.
7. Disassemble all of the pieces of the hydration pack and set them out to dry. It’s best to hang it up upside down so all of the water inside the reservoir can drip out. What’s most important here is that you wait until the hydration pack is completely dry as even the smallest amount of moisture inside can cause mold to grow inside the system.
Can hydration packs freeze? How do I avoid this?
Hydration packs can freeze when used in very cold temperatures. Generally speaking, for a hydration pack to completely freeze, it has to be below the freezing point of water (zero degrees Celsius or 32 degrees Fahrenheit) for a prolonged period of time.
Brief exposure to below-freezing temperatures usually won’t cause a hydration pack to freeze, but these conditions can cause small ice crystals to build up in the tube or mouthpiece of a hydration pack and make it more difficult to drink from them.
The most common part of the hydration pack that freezes is the tube. Unlike the hydration bag, which usually sits right next to your back in your pack, the tube sits out in the open air and is most exposed to the elements.
While the actual hydration bag can freeze, this is more common in very cold temperatures when the heat from your body isn’t transferring through the fabric of your backpack.
Luckily, there are a few ways to avoid having your hydration pack freeze in chilly temperatures:
1. One technique you can try is to blow air into the hydration pack tube after you drink from it.
Doing so helps push warm air into the tube, reducing the likelihood that the tube will freeze. This works best when the temperatures are right around the freezing point, but this is unlikely to make a huge difference in extreme temperatures.
2. Another option is to buy an insulated cover for the tube of your hydration pack. Many manufacturers sell specific models for their products, and they can be helpful in providing a barrier between your hydration pack tube and the elements.
That being said, like the blow-back method, these insulated covers can only help to a point and are unlikely to work well when the mercury drops well below freezing. In these instances, it’s often preferable to use plastic water bottles because there are more methods and techniques available to keep them from freezing.