Update: See the update to this post.
I’m still learning how to do good espresso, and my current technique seems to generate better, more repeatable results than before.
Let your beans outgas before grinding them
Inspired, as usual, by a James Hoffmann video, I’ve started doing this much more regularly after noticing that super-fresh-roasted beans keep on resulting in horrible channeling. So now when I get a new bag of beans I put it into my countertop storage and let it sit there while I finish off the previous bag.
Relatedly, rather than keeping my current beans in an airtight container, I’m actually using the hopper on my grinder instead of single-dosing stuff.
Target 15g of ground espresso
I’ve settled on a 15-gram dose. Since I’m now using the hopper instead of single-dosing, I’m continuously adjusting my grind timer; I first tare my scale with the dosing cup, then put the dosing cup under the grinder, run it for my set time, then weigh the ground beans and then adjust the timer based on targeting 15 grams (for example, if my grind time is set to 4.5 seconds and I get 13 grams ground, I adjust the timer to \(4.5s \times 15g/13g = 5.19s\)), and then also grind a bit more until I get to 15 grams. If my initial grind was too much I just go ahead and use a larger dose.
Sideways-tap level, then WDT, then sideways-tap again
I’m no longer using the spinny-spinny leveler, unless I’m having a really difficult time getting the puck level before tamping. I am using a WDT for declumping. I’m still using the crappy WDT but I will someday get around to printing one of the acupuncture-needle ones that everyone’s in love with now.
Calibrated tamper, but go extra
Instead of trying to get a precise pressure-based tamp, I’m using the calibrated tamper by Decent to indicate the minimum force to pack it down by. Apparently it’s easy to undertamp a puck but pretty much impossible to overtamp, and the depth-based tamping I was doing before was way too inconsistent, especially when using lighter roasts (which tend to grind denser).
(If you don’t want to pay the premium for the Decent tamper, this one on Amazon looks pretty okay.)
Extract based on time, not ratio
This is a thing that’s made a huge difference to the quality of my output. Instead of targeting a 1:2 in:out ratio and adjusting the grind to get it closer to 25 seconds, I brew for 25 seconds and then adjust the grind to get it closer to a 1:2 ratio. Extraction time is the primary driver of flavor profile, and a 25-second extraction seems to get pretty close to the peak. So if my grind is too fine I might get a 1:1 ristretto, or if it’s too coarse I might get a 1:3 lungo, but either way I’ll end up with some pretty good-tasting espresso (although a lungo will tend to be a bit more bitter than I like).