Thank you, Hacker News, for promoting — if only briefly — this marvel of an article from Physics World (or is it physicsworld?) about the more scientific aspects of the final and most important step of making coffee. Funnily enough, it focused on the two methods I’ve settled on after a couple of decades of tinkering: espresso and pour-over.
Refreshingly, it is not a “well-actually” article that would use theoretical physics and/or laboratory experiments to prove coffee experts wrong. In fact, much e-ink is spent confirming practices that baristas have settled on, including the coffee-to-water ratio, steeping time, pressure used. There were, however, two things that could make me change how I’m doing things.
For espresso, theory says that using less coffee with a coarser grind would — to me, paradoxically — result in equal extraction and coffee tasting the same despite not using as many beans. With the price of coffee rising, this could be a big deal so I will check it out. Although, to me the benefit of a proper espresso is that it allows you to get a tasty liquid out of sub-par solids, so I would never go with the most expensive beans to begin with (ahem). No, the $2/oz bag is reserved for the queen of brewing, which is the pour-over.
And for the pour-over, there is but a single thing I should change: the height from which I pour, which should apparently be far higher than I’m doing now. A pretty diagram shows the reasons why 20cm is the right height from which the stream of hot — 96°C, thank you very much, so you’d better have a temperature-controlled kettle — water onto a coarsely ground pile of dreams. And there is no safe way to do it from that high up without a gooseneck kettle, so add that to your kettle requirements. Sadly, they don’t go into the quality of the filter and the differences between plain paper, Chemex and metal meshes. I am sure there is much physics involved.
Now before you start commenting that good ol’ Folgers in a hotel room drip machine will do for you, thank you very much, let me suggest a few decidedly unfussy methods of coffee making that are infinitely better than drip coffee out of a plastic tub:
- Aeropress, which used to be the main way I made coffee but abandoned as the family and the number of coffee-drinkers in the house expanded (we are currently at three; five with grandparents visiting).
- Nescafe Gold, which is probably the best instant coffee you can get and it doesn’t get any less fussy than pouring hot-ish water into a mug.
- Turkish coffee, with strong preference for Mehmet Efendi which, if not in Istanbul, you can easily get online.
- Boiling raw beans in DC tap water for about 30 minutes.
Okay, maybe not that last one.