Review: Miir Tomo and Stainless Steel Cold Brew Filter

Miir has expertly positioned itself at the intersection of beauty and philanthropy. Their functional designs are aesthetic and durable, and as a certified B-Corp company,  Miir has long demonstrated a commitment to environmental causes, social initiatives, and providing clean water to communities around the world. Some of their newer products – the Tomo and the Stainless Steel Cold Brew Filter – highlight Miir’s ability to create exceptional and ethical drinkware.

Miir Tomo Features:

• 1 liter capacity
• Two 8 oz. cups that screw on to the top and base for easy travel
• A push button leakproof lid
• Thermo 3D Double wall insulation keeps your hot beverages hot, and your cold (brew) beverages cold!
• Roll-stop handle
• BPS Free
• MSRP: $59.95

Miir Stainless Steel Cold Brew Filter Features:

• Compatible with both the Tomo and Wide Mouth Bottle
• Micro-perforated steel filter produces a clean and enjoyable cup of coffee
• Fold-down handle for easy use
• MSRP: $14.95

Miir makes small-batch brew easy

Honestly, you don’t know what makes a flask great until you try one that is truly fantastic. The Tomo, which derives its name from the Japanese word for “friend,” is a thoughtfully designed and well-executed travel canister. The roll-stop handle was a feature I didn’t know I needed, but now I don’t want to go without. Have you ever dropped a large water bottle, just to be subjected to an embarrassing chase after it rolls across the floor or ground? The roll-stop handle ensures that won’t happen. The rigid yet ergonomic design is comfortable to carry, even when the Tomo is filled up with coffee (or an entire bottle of wine).

Another thoughtful feature was the integration of not one, but two 8 ounce cups. As implied by its name, the Tomo is meant for sharing, and this is made easier by the dual cups. No more packing extra vessels on your camping trips or picnics for two. These double walled insulated cups fit perfectly on the top and bottom of the container, and makes so much sense that I wonder how it’s possible that no one has thought of this before. They are comfortable to drink out of and the wide mouth design makes it easy to wipe them out before screwing back onto the Tomo.

The double wall vacuum-insulation is Miir’s Thermo 3D technology, which is designed to keep hot drinks hot and cold drinks cold. I put this to the test when I made a batch of cold brew right as I was heading out the door to go camping for the weekend. I threw some cold water and an ice cube into the Tomo in hopes that my cold brew would stay cool until the next morning when I drank it. Lo and behold, after removing the Stainless Steel Cold Brew Filter, my coffee was still cold!

The push-top lid is easy to use and allows you to pour the contents of the Tomo from any side. While I found it a little tough to see whether the lid is sealed or not, I learned later that there is a discreet line on the inside of the lid that indicates when it is open. The matte enamel is lovely to look at, and particularly pretty in white. However, it’s worth noting that some degree of wear will be evident if you choose the Tomo in white. After a long weekend bopping around the back of my van and camping creekside, there were a number of superficial smudges and scratches to the exterior.

While the Tomo is an incredible vessel on its own, I also paired it with the Stainless Steel Filter to make some cold brew at home. When I moved from Washington to Arizona this summer, it was clear early on that hot coffee could not be my only option anymore. The last thing I wanted to do was drink 150 degree coffee on a 115 degree day. So when Miir launched their reusable cold brew filter, I was ecstatic. Having previously worked in specialty coffee, I’ve made many large batches of cold brew and was glad to have a small-scale, reusable option at home.

The filter is micro-perforated stainless steel, similar to what you’d find with a reusable Aeropress filter or pour over filter. These tiny holes retain unpleasant sediment while still providing a flavorful cup. The fold-top handle lays flat for easy storage. Although be warned that the handle is held in place with two small holes, and if you pull on it too hard it could disconnect from the filter. An easy fix, but it would be a bummer to lose the handle.

I decided to test out the filter by comparing it to a cold brew purchased from a local specialty cafe. I bought a bag of the same coffee beans they used in their cold brew, and took home the same water they used to brew in the shop, later comparing my brew to a cup of theirs.

A couple things to note: I decided to nerd out a bit and used a very simple TDS (total dissolved solids) meter that we had in our cupboard from my partner’s coffee roasting days. TDS is a measurement of how much coffee solids end up suspended in the water, thus producing the strength of a cup of coffee. A higher TDS means a “stronger” cup of coffee; a lower TDS means the coffee will taste weaker or “thin.” TDS and strength is distinct from “extraction,” but that’s a conversation for another day.

The TDS reading of the water was very low: 34 parts per million (ppm). The cafe I got the coffee beans and water from likely used reverse osmosis water in their brewing, which lends itself to such a low TDS reading. This number just helps me understand how much of the actual coffee is being read by the TDS meter, as opposed to the mixture of solid minerals in water and the dissolved solids of the coffee.

Still with me? Great. I brewed the coffee according to Miir’s instructions, using 85 grams of medium-coarse coffee and filling with water until it reached the top line of perforations. This ended up being about 765 grams of water, indicating a 1:9 coffee to water ratio. Cold brew from coffee shops will often be somewhere between 1:4 and 1:9 for a cold brew concentrate, then cut with ice and water to dilute. So this measurement provided by Miir seemed on par with my expectations.

The filter fit perfectly into Tomo, and the actual preparation of the coffee was a breeze. Pour in the grounds, fill it up, let it drain, repeat till full. After that I just popped on the lid and called it a day, leaving it for 8-10 hours to brew. The insulated Tomo (as well as the Wide Mouth bottles) maintain the cold water temperature, eliminating any need to refrigerate while brewing. Like I mentioned earlier, this worked out beautifully when I made some cold brew the morning I headed out to go camping.

Eight hours later and I was ready to taste. The final reading on the TDS meter was 20,500 ppm for the coffee I brewed at home, and 10,100 for the cold brew provided by the cafe. These numbers may seem way off from one another, but remember that this is what would generally be considered a cold brew concentrate. 50% dilution was almost certainly the next step at the cafe, making the 20,500 ppm just right for a 1:1 dilution that would land at around 10,250 ppm.

I chose to drink it as is, diluting only with ice, and was tremendously satisfied with the punchy flavor and smooth mouthfeel of the coffee. Admittedly, I preferred it to the cafe’s cold brew. There was a bit of ultra fine sediment left at the bottom of the cup. However, it would be hard to believe such sediment could be filtered by anything other than paper.

The Good

• Loved the thoughtful and useful design features in the Tomo
• The two cup integration is a game-changer!
• The double walled vacuum-insulation performs well
• The Stainless Steel Filter produces a delicious and smooth cup of cold brew
• Miir provided great instructions for how to use the filter

The Bad

• The lid of the Tomo is a little hard to screw on properly when the Stainless Steel Filter is inside
• The enamel finish in white is unlikely to stay spotless, particularly if you plan to use this on more adventurous outings.
• The filter doesn’t sift out ultra-fine particulates

The Bottom Line: Miir Tomo and Stainless Steel Cold Brew Filter

Ultimately, the best cup of coffee is one that tastes good to you. So although the numbers experiment was fun for me to try, I was overall just happy to have a great cup of cold brew. The added delights were the thoughtful features of the Tomo, the ease with which I could share drinks with my partner while camping, and the joy that is enjoying coffee together.

Buy Now: Visit Miir.com