Need to talk about coffee stuff today guys. Gotta keep my mind off the news as much as I can.
I still use my chemex for washed multicup brews. I think it excels at this, and I love the asthetic. I have a handmade wool cozy for it and a 3d printed lid to keep these larger brews warm though and while the cozy is protective, I do worry about breaking this fragile brewer.
It seems like the Miir directly addresses the thermal and fragility concerns and still allows use of the chemex filters. Seems hard to argue with that.
Other than nostalgia and maybe not wanting to spend a cool $80 right now, any reason to hold on to the Chemex?
I wouldn’t consider these huge issues, but there’s 3 areas where I think the miir design suffers relative to the chemex. The pourover part looks like just a single wall. Obviously the chemex is, too, but according to a quick look on wikipedia, stainless has ~10x the thermal conductivity of borosilicate glass, so your brew chamber is going to cool more quickly. No clue if it would be enough to make a difference in brew temp, though.
The stainless carafe part sounds good, too, but stainless travel mugs almost always get lots of coffee residue buildup, and it’s a bit of a process to get them properly clean to the point where you don’t smell it. I always end up washing with baking soda and/or citric acid a few times. Glass stays cleaner, and it’s also easier to see how clean it is.
Lastly, it might just be me, but every once in a while, my scale times out if I’m doing other stuff while making coffee, or I’ll make coffee without a scale. It’s really nice to be able to see visually how much coffee there is in the carafe.
Glass has double the heat capacity, and I would assume greater mass due to thicker construction. So unless you are preheating fully to boiling temps first every time, there will be more heat loss to the glass over the course of ~1-3 minutes
For what it’s worth, wetting paper filters is usually done with near boiling water in the chemex, so it IS preheated with the regular process. Preheated steel also won’t retain as much heat. I don’t disagree with your post as written, it just doesn’t match the reality of what’s usually done
Conductivity is more germane to heat loss through the material. Borosilicate glass’ specific heat is also roughly twice that of steel, at around 0.830 J/g C to 316 steel’s 0.468 J/g C. Glass will absorb and retain more heat for longer;steel will absorb energy and heat up more quickly, and dump it just as fast.
I mean, we’re taking about millimeters of material; the quality of the cozy will have far more impact than the container material.
Which was my point - 400g of room temperature ceramic is going to absorb way more heat from 250ml of boiling water than would be lost from the glass-air (or even steel-air) interface during the 2 minutes it takes to do a pourover.
If both cones are preheated thoroughly, yes, the steel cone will shed heat faster, however I feel like this is also negligible compared to evaporative heat loss and subsequent transfer to a cup
Yah, you may be right. I’m at the limit of my materials science knowledge, here.
Thanks. These are great points. Agree with you completely about cleaning stainless. I was hesitant to introduce stainless into my brewing at all because of this. We’ve probably all smelled thermoses with a seemingly permanent coffee aroma. I did give in last year and have been brewing with my orea big boy directly into a stainless thermos. I’m really paranoid about keeping it clean whereas I just kind of use visual cues with the chemex. For now at least I use unbleached chemex filters which require heavy hot rinsing so I’m always thoroughly preheating. I think I’ll hold on to my chemex for now unless partner complains too much about cold coffee or it breaks, in which case the Miir seems like a worthy replacement.