Photo credit: Casey Klekas, because it's a much nicer shot than I can produce in my ugly little kitchen. I do have that same kettle though.
I don't listen to many tech podcasts these days and thus I'm not subscribed to John Chidgey's show, Pragmatic. (Sorry John. It's not you, it's me.) But when the latest episode—in which Marco Arment guest-hosts to wax scientific about coffee—came up in my Twitter feed, I couldn't add it to my Huffduffer queue fast enough.
It's a great listen if you consider yourself a coffee nerd, and quite educational if you're a newbie. I particularly liked hearing Marco discuss why he doesn't fuss over his brewing process anymore. His method is similar to my own, but mine is even simpler in some ways:
I add about 1 (U.S.) cup of water to my kettle and bring it up to 195°F.
While the water heats up, I scoop some freshly-ground coffee—the most important factor, really—into my inverted Aeropress, up to the "bottom" of the #3 circle (the plunger having been inserted just enough to touch the #4 circle). I don't have a kitchen scale to weigh my coffee, but over time I've found this amount works nicely for me.
When the water's ready, I pour just enough to coat the grounds and let them bloom for 45 seconds to let out all that trapped carbon dioxide. Marco derides this very practice on the podcast, and maybe it is just placebo, but I do it anyway.
At the :45 mark, I add water to just under the top rim of the Aeropress, stir the slurry mixture around a bit, and let it steep another 45 seconds. At this point I typically run just a little of the hot water through the Aeropress filter/cap, not because I've ever detected any paper flavor in my coffee (I haven't) but because it helps the filter adhere to the cap when the time comes to flip it over.
At the 1min 30sec mark, I twist the cap on, flip the Aeropress onto my trusty coffee mug, and plunge. I try to finish before my iPhone timer reaches the 2min mark, and I always stop as soon as I hear any hissing noise coming from the Aeropress. Again, this might be placebo, but I've read that plunging any further will extract the more bitter flavors into the cup.
And that's it!
If this seems like a lot of details to remember, just know that writing it all out like this is severely more complicated than the actual brewing process. It takes me about 7min from start to finish, and most of that is waiting for the kettle to heat up.
The point I want to get across here is that I don't worry much about exact measurements. Like any recovering coffee nerd I've tried experimenting and being fussy and even emulating Aeropress championship recipes, but again, the most important factor by far is using recently-roasted, freshly-ground beans. If you start with good beans and a little practice, it's hard to screw up the end product.
As for the iPhone timer, I don't use any fancy coffee apps. I've tried a lot of them and always come back to the stopwatch bundled with the built-in Clock app. It's simple and it works fine.