Looking for clean drinking water anywhere in the world? Grayl have you covered. Their bottles allow you to purify water from any source, are easy to use and, as the saying goes, are as tough as old boots!
Grayl’s first bottle, the Ultralight was a revolution for travellers and outdoor folk. Their second bottle, the GeoPress, blew the doors off the filtered water bottle industry.
And their third?
Let’s find out in this Grayl UltraPress review!
Disclaimer: Grayl sent us the UltraPress free of charge to test and review. We wrote this review after years spent testing and evaluating the UltraPress. The review was not sent to Grayl before being published. None of our reviews are ever edited to keep a brand happy.
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Grayl UltraPress Summary
Grayl UltraPress Summary
- Size: 25cm x 7.5cm | 10 x 3 inches
- Weight: 357g (dry) | 857g (full)
- Volume: 499.7ml | 16.9oz
- Filter Time: A claimed 3L/min but in reality, you’re lucky to get 1L/min
- Filter Lifespan: 300 presses | 150 litres
- Removes: 99% of Viruses, Bacteria, Protozoa, Particulates, Heavy Metals, Chemicals
Grayl’s UltraPress is a combination of their first two bottles. It looks like a GeoPress with a similar screw cap, lid and carry handle but is much closer in size to the Ultralight. It’s easier to use than the Ultralight while being easier to pack than the GeoPress.
The biggest downside of the UltraPress is the limited capacity. Holding just over 500ml of water, you’ll need to purify and decant several bottle loads if water sources are scarce.
- Fits into backpack bottle pockets.
- Relatively lightweight.
- Makes almost any freshwater safe to drink.
- Simple to use.
- Saves money on single-use plastic water bottles.
- Small capacity.
- Still heavy for a water bottle.
- Filter lifespan.
- Takes some strength to use (especially when the filter is nearing the end of its life).
Grayl UltraPress – In-Depth Review
We’ve used our UltraPress purifier bottles extensively, purifying hundreds of litres of water that would otherwise have been undrinkable. From tap water in South America to flowing rivers in the Scottish Highlands and stagnant ponds in Europe, when things really got desperate, the UltraPress bottles have kept us hydrated and allowed us to reduce our plastic footprint while on the road!
How the Grayl UltraPress Works
Grayl’s UltraPress purifier bottle contains a filter which removes 99% of viruses, bacteria, protozoa, particulates, heavy metals and chemicals from your water.
To do so, the UltraPress relies on three filtration technologies:
- Electro Adsorptive Media
- Ion Exchange
- Activated Carbon
The electro-adsorptive media acts like a magnet to pull pathogens and other contaminants out of the water. The process of adsorption, not to be confused with absorption, involves these pathogens and contaminants becoming permanently bonded to the adsorptive media and removed from your water.

Ion exchange is similar but different. At a molecular level, pathogens bind permanently to the filter thanks to an electrical charge. These waterborne pathogens include viruses, bacteria, cysts, protozoa, etc. Ion exchange can be used to get hold of pathogens too small to be stopped by a regular mechanical filter.
The activated carbon absorbs chemicals, heavy metals, flavours and odours to ensure your water is safe and tastes fresh!
How to Use the Grayl UltraPress
As with all Grayl bottles, the UltraPress is simple to use – although it does require some effort.
Remove the inner bottle and fill the outer with dirty water. Unscrew the cap about a quarter of a turn and push the inner bottle back into the outer. Dirty water is forced up through the filter, purified and enters the inner bottle, where it can be stored, drunk or decanted into a clean container. For maximum carry capacity, we recommend using a collapsible water bottle alongside your Grayl, that can be packed away when not in use!

The filter lasts around 150 litres or 300 presses. However, if you’re purifying very dirty or silty water, the lifespan will be reduced. As you use the Grayl bottle, you’ll notice the press time (the time that the purification process takes) going up. When this reaches around 30 seconds, it’s time to replace the filter.
New filters can be purchased directly from Grayl.
While simple, the purification process does require some effort, especially as the filter nears the end of its life. Due to the filter’s small pore size, the press required to force water through the filter can be tough on your hands, arms and shoulders.
However, it’s worth the effort as the filter stops viruses getting through, which other filtered water bottles fail to do!
It’s worth noting that Grayl claim the flow rate (speed of water purification) of the UltraPress is three litres per minute. In reality, you’re lucky to get one litre per minute. The time it takes to fill, press and decant water from the 500ml bottle makes it impossible to purify three litres per minute.
Although the UltraPress requires a bit of oomph to use, it’s not at all complicated. The simplicity and speed at which you can get clean water makes the effort worth it!
Size and Weight
Clocking in at over 350g when empty, the Grayl UltraPress is heavy compared to average reusable water bottles – especially for the volume of water it holds. It’s around 10x more than a single-use plastic bottle!

The Grayl is also large for the volume of water it holds. This is in part due to its rugged structure but mainly because of the purification system. The filter takes up a chunk of space and the two-layer design of the bottle adds extra width. The UltraPress fits into bottle pockets of most backpacks but it’s quite snug, especially if your bag is full.
Top Tip
Overall, the size and weight of the Grayl UltraPress are slightly off-putting but the advantages of the bottle outweigh this slight nuisance!
Grayl’s Ethos
Grayl is a company built by travellers and adventurers. Not only do they understand exactly what people want and require from outdoor gear, but Grayl are also keen to give back to the world. As a member of 1% for the Planet, Grayl donate at least 1% of their sales to fund environmental causes.

They’re also members of The Conservation Alliance, All Hands and Hearts, charity: water and are supporters of many more groups and organisations.
By buying any Grayl product, you’re giving your money to a company that cares about our planet and its people.
How to Extend the Lifespan of Grayl Filters
You can’t really ‘extend’ the lifespan of your Grayl filters but you can make sure they reach the 150L mark before they need to be replaced. These top tips will help you get the most out of your filters and apply for any water bottle with a filter, not just Grayl bottles!
- Always try to filter clear water. The dirtier the water, the quicker your filter will clog up.
- Always try to collect flowing water for filtering – the faster, the better. Fast-flowing water has less dirt and sediment in it.
- Only filter fresh water. Never try to filter salty or brackish water. This will destroy the filter. The same is true with other liquids. Stick to filtering fresh water.
- Clean and dry the bottle between uses. Always remove the filter and clean the rest of the bottle with warm soapy water if you won’t be using it for a while. Leave the filter upside down in a warm room to dry out. It can take days for the filter to dry completely.

Grayl UltraPress FAQs
What is the lifespan of Grayl?
The Grayl UltraPress filter should last for 150 litres or 300 presses. But if you use it to purify dirty or stagnant water, expect the filter to clog up faster. When a press takes around 30 seconds, the filter needs replacing.
Can you use a Grayl for tap water?
Yes, you can use a Grayl bottle for tap water. Tap water is more likely to contain viruses than water from rivers or streams. If you filter tap water, make sure you’re using a purifier like the Grayl UltraPress. This removes viruses whereas other popular filters like LifeStraw, Sawyer or the Katadyn BeFree do not.
Can you use Grayl without filtering?
To use the Grayl as a normal water bottle, remove the filter (to reduce wear and tear) and fill the bottle with clean water. With the filter removed, the UltraPress holds more than the advertised volume of water. However, you need to be very careful when doing this as the inner bottle can slide out very easily causing you to spill water everywhere! You can also use the bottle with the filter in but this can cause unnecessary wear and tear.
How do you clean a Grayl bottle?
If you have access to a dishwasher, most of the Grayl UltraPress is dishwasher safe. The filter isn’t suitable for the dishwasher, so make sure you remove it first.
If you’re somewhere like a hostel, with no access to a dishwasher or safe tap water, you can wash the GeoPress with warm, soapy water. The washing-up liquid will remove any germs or bacteria. Allow the bottle to air dry after cleaning.
Grayl UltraPress Review: A Round-Up
The Grayl UltraPress is one of the most practicable water purification systems for travellers. It’s small enough to fit in any travel bag, is simple to use and makes almost any freshwater safe to drink. I’ve used my Grayl bottles to drink from stagnant ponds in Europe, fresh mountain streams in Scotland, questionable taps in Panama and flowing jungle rivers in Colombia.
While heavier and much more expensive than a standard reusable water bottle, the UltraPress is worth it. You’ll save money vs buying bottled water and unless you’re right on your luggage limit, the 350g bottle won’t be noticeable in your backpack.
I now take my UltraPress everywhere. Whether it’s for a day hike, weekend city break, or extended backpacking adventure, I always make room in my bag for a Grayl!
Without getting too personal, my Grayl UltraPress has not only saved me money on buying bottled water, it’s also saved me a huge amount on Imodium too! If that’s not an endorsement, I don’t know what is!
The Grayl UltraPress allows you to drink from almost any tap or water source in the world. It saves you from buying bottled water which is great for your wallet and the planet!
- Makes almost any freshwater drinkable
- Saves you money
- Reduces your plastic footprint