Coffee with a splash of physics: how to make the most out of your brew

zahma 26 minutes ago | parent | next [-]

In the pour-over section, the authors hit on a good point about height and creating a vortex in the slurry. Water temperature and flow rate are important variables too. Combined with the coffee grounds' quality (i.e. grind consistency) and whether it has fines or lots of chaff will also dictate how long it takes to draw down and therefore whether the pour height's effects will change if static.

I do like the advice grind coarser and extract with more water -- that's made my V60 coffee quality fairly consistent, but everyone's mileage will vary based on how they like their coffee and the roast profile.

There are so many other variables that didn't get a mention: Coffee varietal

Water hardness (and even which other ions are present in the water) and its effects on acids and other compounds that highlight certain varietal's defining characteristics.

Vessel temperatures.

The filters used (materials, paper thinness).

Pouring patterns (circular, concentric, hypotrochoid, more?)

The filter shape and material.

Even the grinder used conical vs. flat burrs and high RPMs vs. low RPMs creates palpable flavor profile differences.

The rabbit hole goes deep and continues to expand.

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aboardRat4 6 minutes ago | parent | prev | next [-]

The HTTP 418 I'm a teapot status response code indicates that the server refuses to brew coffee because it is, permanently, a teapot. A combined coffee/tea pot that is temporarily out of coffee should instead return 503.

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mr_mitm an hour ago | parent | prev | next [-]

> The bottom line of the team’s experiments and mathematical modelling is that to get the most reproducible shots just use less coffee and grind it more coarsely.

This seems to go against conventional wisdom, which says that less coffee will reduce brewing time and a coarser grind will also reduce brewing time, and consensus seems to be that you want a brewing time somewhere between 20 and 30 seconds. Or did I misunderstand something?

Anyway, the reasoning seems sound, so I'm going to have to give this a try.

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sgc 30 minutes ago | parent | next [-]

They failed to mention the important point, that you have to be able to reduce the pressure to increase the grind size. I am convinced the best espresso you can make is at 6 bar, since you can grind the coarsest possible. It comes out sweeter and richer at the same time.

	▲	criddell 20 minutes ago \| parent [-]
		Some people go all the way down to 1 or 2 bars (soup espresso). I've mostly seen it in the context of very light roasts and I tend to buy darker roasts so I really haven't spent much time investigating it. I did see a video on americano's recently where steaming the water to heat it rather than using a kettle or water from the espresso machine's boiler made a better drink. That does intrigue me and I'll probably give it a try this weekend.

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FrustratedMonky an hour ago | parent | prev [-]

Yeah.

"most reproducible" -> Does not mean good.

A lot of generic weak coffee is 'consistent', but not 'good'.

	▲	mr_mitm an hour ago \| parent [-]
		Sorry, maybe I should have quoted the next line as well: > Pabst echoes that advice: “My recommendation for people at home, without knowing anything they are doing, 90% chance that if you use less coffee and grind a little coarser [your coffee] will actually taste better.” So it's not just about consistency, but also quality.

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urxvtcd an hour ago | parent | prev [-]

For an entire book about the topic, see "The physics of filter coffee" by Jonathan Gagné.

Also

> This can be achieved using an espresso machine (figure 1), or with smaller contraptions at much lower pressures such as a moka pot or AeroPress.

Please, just stop. They're not even remotely close.