alt Hacker News> 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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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.
Reproducibility doesn't mean good.
I can make bad coffee every time myself by putting 2 spoons of vinegar in it.
You're spot on, but this coarser, faster-style shot is called the "turbo shot" and you don't actually have to use less coffee, you can actually use more - just compensate your grind to brew quickly. You will get more consistent results here, but they're very different from traditional espresso.
But, I think for any recipe, "total brew time" is just a way to communicate contact time with water, and should NOT be a goal unless you're trying to copy what someone else did with that same coffee, and is IMO more important for pour over in that regard than espresso.
Yeah.
"most reproducible" -> Does not mean good.
A lot of generic weak coffee is 'consistent', but not 'good'.
These was actually a sort of fun and popular research paper about this,
https://www.cell.com/matter/fulltext/S2590-2385(19)30410-2
They suggest a courser size and less pressure to avoid channeling.
I’ve been using this technique for a while, I think the results are better (but of course there’s a strong bias when people think they are doing the cleverer thing in food preparation).
For light roasts I hold the pressure at around 1 bar for ~30 seconds before increasing to 7 or so.