I was shopping for a new coffeemaker, and wanted one of the Keurig models. These use pre-measured “k-cups” of coffee, which you put into the machine, and in less than 60 seconds, your coffee is ready-to-drink. Comparing the different models available, one of the main differences was the ability to make different sizes of cups; one model offered the user four choices cup sizes: 6, 8, 10, and 12 ounces, if I’m not mistaken. I was very curious how the machine manages to use such widely vaying amounts of water with the same prepackaged amount of coffee.
I ended up choosing the “B-50” model, mostly because it was for a great price, and was the only model available at Costco. Page 4 of the manual says
Following this logic, it seems to me that a 12-ounce cup made with this same amount of ground coffee is going to be quite weak. What are other people’s experiences? Do the larger machines have some way to strengthen the coffee? For example, do they run the water through the k-cup a second time?
I don’t know how that would work out, but are you sure you want to lock yourself into buying prepackaged filters? There is such a variety of great coffee out there.
I have seen such coffee makers as you describe in the OP in discount stores - though I’m not sure of the name brand, and it appears like the coffee makers they are almost giving away, which makes me think they are going to stick it to you with the coffee packets you have to buy from them.
The way I understand the brewing process is that no method extracts all of the soluble coffee bits from the fresh grounds. To extract more (get stronger coffee or more coffee), you increase temperature, pressure and time. There’s obviously a limit to how much you can extract from a given set of grounds, but I would guess that most drip-like coffee making processes don’t come close to extracting 100%. So it’s quite possible that the 12-ounce cup and the 8-ounce cup have very similar strength.
In other words, a given set of grounds is going to have a “brewing” curve for each method used. You’re drawing out coffee solution into fresh water at a certain rate that certainly can be near-constant (although I am not sure that this is actually the case) for a given range of volumes/time.
Although their mention of the larger cup being weaker makes me think that the machine doesn’t bother changing the settings, just the amount of water it puts through.
I have this Keurig K-cup style of coffeemaker at work and at home (I got the “Special Edition” brewer that makes three sizes, in 5-1/4, 7-1/4 and 9-1/4 oz). I quite like it as the coffee comes out pretty much just the way I like it every time (the Green Mountain Columbian particularly). It tastes like fresh ground (to me) without the hassle of grinding and cleaning up stuff. I can take home some of the Green Mountain K-cups from the office for free coffee, or use this reusable K-cup coffee filter for my own fresh-ground coffee when I feel like it.
That said, you are right to be suspicious about the small, medium and large cups all being made with the same amount of coffee. As far as I can tell, all that happens is that more water runs through it. YMMV, of course; try making the 8 oz. cup and see if it’s palatable to you first, but I have tried making the larger cups of coffee versus the smallest one, and it definitely tastes “watered down” to me. And the “corporate grade” Keurig machine in my office doesn’t even allow me to specify an alternate size (it always comes out as a 6 oz. serving).
To fill a larger mug, I make multiple servings of the smallest size cup. I use 2 K-cups to make two 5+ oz. servings to fill a large travel mug (leaving some room for milk).
Well my point was that you wouldn’t necessarily have to change the settings. I simply don’t know enough about coffee to claim one way or another, but this seems reasonable to me. Each drip spends roughly the same time going through the coffee, and is roughly of the same volume. The strength of each drop of coffee coming out can be almost constant until a certain cutoff point after which the “easily brewed” part is over and you either need to increase temperature, time or pressure to brew same strength.