Reviews You Can Rely On

Miir Slate 27 Review

The Slate is a lightweight, stainless steel water bottle that is versatile, stylish, and easy to use
Miir Slate 27
Photo: Miir
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Price:  $20 List
Pros:  Lightweight, easy to use lid, good color options, inexpensive, stylish
Cons:  Large handle, paint scratches easily
Manufacturer:   Miir
By Jane Jackson ⋅ Senior Review Editor  ⋅  Jun 28, 2017
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  • Ease of Use - 35% 9
  • Durability - 20% 7
  • Ease of Cleaning - 20% 7
  • Weight - 15% 9
  • Taste - 10% 8

Our Verdict

The fairly small and little-known company, Miir, rose to the top of our list quickly by creating a lightweight, sturdy metal bottle. The Slate stole the show during our review update and became our Top Pick for Lightweight Stainless bottles. Competitors like Klean Kanteen and Hydroflask, and even CamelBak have made stainless steel bottles, but we like the simplicity and lightweight portability of the Miir. The bottle has a slim profile, an easy to carry handle, and comes in a good range of color options. It is a refreshing take on the classic stainless steel bottle and we were always happy to take it out into the field during the testing period.

Our Analysis and Test Results

In nearly all of our rating metrics, the Slate shined. It is lightweight, easy to fill, carry, and drink out of, and has a sleek, stylish design. The Miir bottles come in a few color options and has a unique triangular carrying handle that feels comfortable in your hand. For a reasonable price, the Miir is a great all-around bottle, and, the company donates money to local and international water-related non-profits, which is an added plus! There are just a few minor downsides, the first being the size of the handle, which is large for the bottle. It fits even the largest fingers, but standing alone or floating around in a pack, the handle could get in the way.

Performance Comparison

The Miir works well as a crag bottle for climbing, as it is...
The Miir works well as a crag bottle for climbing, as it is lightweight and durable.
Photo: Jane Jackson

Ease of Use

Right out of the box, we loved the design of this contender. A slightly different take on the stainless bottles we've seen from Hydroflask and Klean Kanteen in the past was exciting as a water bottle aficionado. The Miir is slightly slimmer than the Klean Kanteen Classic, and has a larger mouth, making it easier to fill. It is just wide enough to fit narrow ice cubes in, which is a plus on hot days.

The large and triangular handle is another striking feature of the Miir 27oz. At first, it seemed that the lid was too bulky or big for no reason, but after some time with the bottle, we realized the benefits of this style handle. It is narrow enough to clip a carabiner to, unlike the wide handle of the Hydroflask Vacuum Insulated bottle. Its shape also comes in handy when taking the lid on and off, giving you something to hold onto as you twist. Most of all, we appreciated the aesthetics of the bottle overall. After all, a lot of the decision making behind choosing the best bottle is deciding which one is the coolest looking!

The large, triangular carrying handle gives the Miir a unique look...
The large, triangular carrying handle gives the Miir a unique look, and also provides a comfortable way to carry the bottle around with one hand. The large handle is nice to grab onto when removing the lid.
Photo: Jane Jackson


Here, the Slate bottle got docked a few points in our rating metrics, since we found that the paint chipped fairly quickly on our test bottle, though it still earned an above average score.

After just a few days of carrying around, the bottle had a few small nicks and dings in the sides with small flecks where paint had chipped off. This also happened to the Hydroflask Vacuum Insulated bottle, so be aware this is not a problem specific to the Miir bottle alone. Any stainless steel bottle with a powder coat finish will suffer from this problem eventually.

This small indentation occurred when we dropped the Miir bottle onto...
This small indentation occurred when we dropped the Miir bottle onto concrete on its side. A few small chips in the paint, but otherwise the bottle survived the fall unscathed.
Photo: Jane Jackson

Ease of Cleaning

Since the Slate is a narrow bottle, much like the Klean Kanteen Vacuum Insulated and Classic, it is similarly difficult to clean.

With a bottle brush, you can reach the inside of the bottle, though. It's not a bad idea to just have one of these on hand to keep your bottles clean. Otherwise, the Miir is easy to rinse out by hand. Since the threads of the screw cap are on the outside of the cap, its easy to clean the gasket and the threads, unlike bottles like the Nalgene Wide-Mouth and the Hydroflask, where the threads are hard to clean. The company does not recommend putting the bottle in the dishwasher since the plant-based paints will deteriorate under extreme heat.

The exposed threads and gasket on the lid are easy to access and...
The exposed threads and gasket on the lid are easy to access and clean.
Photo: Jane Jackson


For a stainless-steel bottle, the Slate takes the cake as the lightest bottle we tested. At 6.6oz empty weight, the Miir compares to plastic bottles, like the Nalgene Wide Mouth and the Camelbak eddy, both of which weigh in at a little over 6oz, as well.

The lightweight plastic lid and 18/8 kitchen grade stainless steel used in the bottle's construction contribute to its low overall weight. This is an important attribute since a lighter bottle is more appealing to take on long hikes, bike rides, or climbs. Bottles like the Yeti Rambler, which are amazing performers in all other metrics, fall short because they are just too heavy to be useful on day-to-day adventures. The Miir was light enough to carry on multi-pitch rock climbs and on long hikes without being an added burden.


In our initial taste tests, the Slate had no residual drink mix flavor left in it after one use. By simply rinsing the bottle with water after it had drink mix in it for a few hours, we were able to get rid of any fruity flavoring that was left inside the bottle.

We found that with most metal bottles, frequent, simple rinses with water will keep the bottle tasting fresh, even if you fill it with an array of flavored drinks. The lid design also helps mitigate flavor build up by having the threads on the outside and the gasket visible. This way, you can easily wipe down the gasket and threads frequently to prevent mold or flavor build up. The Yeti Rambler has a similar lid design and also scored highly in our taste metric.

Best Application

This versatile, stylish bottle can be used in nearly any situation you can think of. It's great for most outdoor activities from backpacking and hiking to climbing. The 27oz bottle can also be used at work or the gym; its stylish design gets street cred in an urban setting. The lightweight handle can be clipped onto a pack or harness, and the small diameter bottle is narrow enough to fit in cup holders or bike water bottle holders. Usually, the carrying handle or clip loop on most bottles lacks functionality, but the Miir's oversized handle is narrow enough to fit a carabiner but large enough to also fit your fingers in to carry the bottle by hand. Miir also makes wide mouth bottles in different capacities (40oz, 20oz, or 16oz) and a vacuum insulated version of the 27oz reviewed here.

The Miir has a narrow mouth, which is helpful for drinking, but...
The Miir has a narrow mouth, which is helpful for drinking, but large enough to avoid spilling and splashing when filling the bottle.
Photo: Jane Jackson


At only $20, this model is an excellent deal for a stainless-steel bottle from a small, independent company. The Miir bottle costs the same as the Klean Kanteen Classic 27oz, showing that even though they are a hip, up-and-coming company, they are not marking up their products unnecessarily. For a stainless-steel bottle of this size, there is no better deal than $20. The least expensive bottles in the fleet are the smaller capacity plastic bottles, or the classic Nalgene, which sells for about $10. Depending on the material you choose, the price of the bottle will vary. Stainless steel bottles, like the Miir 27oz are typically a bit more expensive than their plastic counterparts.

The Miir is the whole package! Its slim enough to fit in a car...
The Miir is the whole package! Its slim enough to fit in a car cupholder or in the side pouch of a backpack and is durable and lightweight enough to go on any adventure.
Photo: Jane Jackson


Miir combines some of the best parts of our favorite bottles to create the ideal lightweight stainless steel 27oz bottle. The bottle weighs almost as much as the lightweight plastic bottles that are typically our go to for long hikes, but is made of stainless steel, as opposed to plastic. The bottle has a narrow, but not too narrow mouth-perfect for filling and drinking from, but not too small to cause unnecessary spills. The carrying handle is large enough to fit your fingers through, but not obnoxiously so. The bottle still has a slim profile that can fit in most bags without hassle. Finally, the Seattle-based company seems to do good work overall, by donating part of its profits to local organizations.

Jane Jackson

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