I’ve had this cup for just over 5 years. Typically I’ll wait 10 years before doing a “long term” review. I have taken it on every backpacking and car camping (trips without our travel trailer) trip since I bought it. This cup has worked out so well I can’t picture myself wanting something else.
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Weight vs. Function
Often when weight is the deciding factor in choosing a piece of gear, the product often is a compromise on function.
The lightest cup option is zero ounces. One “zero option” is to do without a cup and only drink water from your water bottle. A second “zero option” is to use your cooking pot as a cup. I’ve done both over the years.
But I’ve always preferred an actual cup for drinking.
Integrated Options I Have Used
Svea 123
In the 1970s I, for a short time, used the cup that came with my Svea 123 stove. It didn’t work well. and I went back to my Sierra Cup.
GAZ Globe Trotter
In the 1980s I bought a GAZ Globe Trotter stove that fit inside the two included pots/cups.
Both pots had about the same volume and I could use one as a drinking cup will cooking or boiling water in the other one. The handle was much better than that of the Svea 123 cup.
And I could use the pots to carry my Svea 123 stove, which was a much better option than the original cup that came with the Svea stove.
But in the end, the integrated cups and the several stand alone cups I had been using over the decades all left a lot to be desired. So, what did I want in a cup?
Cup Wants & Needs
- Large volume (at least 16 ounces).
- Easy to hold with very hot drinks.
- Drink hot beverages without burning lips on the cup (problem with metal cups).
- Keep drinks hot (warm) for a period of time.
- A lid that doesn’t leak.
- A lid that lasts as long as the cup (plastic lids with most metal backpacking cups don’t last long).
- Measuring cup markings that are easy to see.
- Be able to nest it with my cook pot (a nice to have).
My typical morning in the backcountry starts while still in my sleeping bag. I fire up my stove and boil water for coffee. I may boil enough for coffee and my oatmeal breakfast. More often than not I make a cup of coffee and enjoy it while observing my surroundings. Once completely awake, I’ll go ahead and prepare my breakfast.
Dinners are somewhat similar. Coffee or hot chocolate while preparing dinner, which is usually waiting for my freeze-dried meal to re-hydrate in boiling water. It also common for me to drink hot chocolate well after dinner while I sit under the stars admiring the night sky.
What I wanted, and never had before purchasing the GSI Infinity Backpacker Mug, was a cup somewhere in the 16 ounce range, that would stay hot/warm during my morning routine. A cup that would not burn my lips at first sip, was easy to hold, and would not spill my coffee if I accidentally knocked it over.
A couple other “nice to have” features would be easy to read volume markings so the mug could also be used as a measuring cup, and the ability to nest the cup inside my cook pot along with my stove.
This is a lot to ask for — and the Infinity mug does them — except being able to fit into any of my cook pots, which is not a deal breaker at all for me.
GSI Infinity Backpacker’s Mug Details
This cup weighs 3.5 ounces for the mug, lid and insulating sleeve. It checks off all my boxes, except as a stand-alone drinking cup it takes up extra space in my pack. I can’t nest it with my cooking pot and stove. It is inexpensive and functional.
Insulation
The GSI Mug isn’t a true insulated product. The thick polypropylene wall has some insulating properties, and is dishwasher safe. The foam cover makes it easy to hold using the nylon handle or you can just wrap your hand around it (like you would hold a tumbler) without it being too hot to hold.
Handle
The handle is made from nylon webbing and folds flat against the cup to save storage space. 
Unique Bottom Surface
Convenient Lid
One problem I had with two titanium cups that came with lids is the lids fell apart after about a year. Another problem with these kind of lids is that the have a “sip” slot and if the cup tips over, the centers will leak out.
The Infinity mug is made from a tough hard material that has held up well. When the lid drink tab is closed, it is secure and will not leak.
Locking tab to keep the drinking lip closed.
Measuring Cup
When the cover is removed (it is easily removed) it doubles as a measuring cup. I do find it strange the measure increments are read from the inside of the mug, not on the outside like most measuring cups. The cup material is clear, so it is easy to see exactly how much is in the cup, whether one is measuring liquid, powder, or some other ingredient.
Cons
The only negative thing for me is that the individual components (mug, insulated cover, and lid) cannot be purchased separately. The o-ring for the lid can be purchased from GSI directly. My only concern is that the mug might become subject to Herblock’s Law, which states:
“If it’s good, they’ll stop making it.”
Just in case, as I often do, I just bought a back-up Infinity Mug. Not that I expect it to fail, but I might lose it or cause it to fail by some kind of abuse, such as accidentally stepping on it or dropping it off a cliff. It’s a fairly inexpensive item, unlike the ubiquitous titanium cup which are much more expensive.
Summary
What stands out
Lightweight & pack-friendly
One of the first things you’ll notice: the Infinity Backpacker Mug weighs just about 3.5 oz (≈99 g) for the mug, lid and insulating sleeve. For backpackers this is a big plus.
Smart materials & design for the trail
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The body is made of BPA-free, non-leaching clear polypropylene.
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Wrapped in a cloth-covered foam sleeve (rPET cloth over foam) for insulation and grip.
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The mug has measurement markings inside (in oz and ml) so you can see how much liquid you have — useful for trail meals, conserving water, etc.
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Lid: sealable sip-through top helps keep spills, dust, bugs out. Several reviewers confirmed good performance.
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Good size capacity: about 16 fl oz (≈500 ml).
Vent-friendly design for camping/hiking use
The wide base, non-slip footing, cozy sleeve handle all contribute to real-world usability: you can grip it with gloves, set it on uneven ground, etc.
Limitations
Insulation isn’t premium
While the sleeve helps, this mug is not a vacuum-insulated mug. Of course the cozy-style insulation sleeve is going to be lighter than a double-walled vacuum-insulated cup, such as the MSR Titan Ultralight Titanium Double Wall Camp Mug with Lid with a capacity of just 12 ounces and weighing in at 4.1 ounces.
Durability trade-off
By using lightweight plastic materials, there’s a trade-off vs extremely rugged steel or titanium mugs. The mug is durable for its price and use-case, but it’s not built like a tank.
Conclusion
If you’re in the market for a lightweight, trail-friendly mug that works well for hot coffee, tea, soup, or just a drink at camp, the Infinity Backpacker Mug is an excellent choice. It strikes a strong balance between weight, capacity, convenience, and usability for back-packers or casual campers.
However, if your primary need is long-term thermal retention (i.e., you want your drink to stay hot for hours), or you’ll be doing very heavy, rugged use (where steel/titanium might be better), then you might want to consider alternatives.
Final thoughts
The Infinity Backpacker Mug delivers on what it promises: a light, feature-rich mug suited for outdoor use. The measurement markings alone show that someone designing it thought about real-world trail needs. The materials and design show an evolution toward eco-friendliness and packability.
It might not keep coffee piping hot for hours in freezing conditions like a vacuum steel mug, but for typical hiking mornings, it will perform very well. If cleaning is easy and you manage your expectations on insulation, you’ll likely be very happy with it.
