Dose Espresso by Volume, Not Weight

More effective puck prep: There's an ideal volume of coffee for every basket, and an ideal gap between the puck and the shower screen. I'll show you how to measure the headspace, make corrections, and develop recipes on the basis of a sensible volume of coffee, not some arbitrary weight. This alone will eliminate a number of persistent flaws.

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Audio capture: Zoom H-5
Audio edited with WaveLab Elements 10.0.70
Video Capture: Panasonic HC-X920
Video edited with DaVinci Resolve 18.0.3
Still images edited with Gimp 2.10.240

Production Assistant: Leo Greene

Music:
Kalimba Relaxation Music by Kevin MacLeod
Acid Trumpet by Kevin MacLeod

[scviper]

While the advice in this video is extremely useful and sensible, the puck press is not for hiring unskilled barristas, I feel like that is not only incorrect but also slightly damaging, if everyone takes this seriously.

Reasons to use a puck press:

- save your baristas from RSI (repetitive strain injury). In a cafe where you pull hundreds if not thousands of shots a day, RSI is a real problem.
- you have some recipes which require a certain amount of pressure. This is absolutely not transmissible between baristas. You dial in the coffee once, at the beginning of the day. After that, you want to keep all the parameters the same - you have the weight and shot time, but you might, for example, want only 5 or 10KG of pressure on your tamp. This is not doable by hand and might change the way the shots pull. A puck press is great at this.
- speed: no matter how fast you are and RSI aside, a puck press is still faster and error free, when you have to pull shot after shot after shot.

[ridethree]

Interesting points raised here, a couple of questions:
1. How do you know that approx. 2mm is the perfect amount of headspace?
2. Different coffees also take up different amounts of water, so shouldn't you measure headspace after preinfusion, when the puck is water saturated?
3. What would be the disadvantage in underfilling the basket and leaving a lot of headspace? From a flavour extraction perspective of course, because I know it might get messy to clean up.

[nichj]

One key factor here is to make yourself familiar with how tapered your basket is.

The VST basket I use with my La Marzocco does not have much of a taper, so the tamper only ‘grabs’ the inside surface when I’m down to the bottom 25% of the basket.
So I could conceivably dose as low as 10g in an 18g basket without any issue. Scott Rao and the folks at Decent ran testing on the importance of head-space, and found that providing more room actually leads to higher extractions.
Take from this what you will, but it seems to suggest that there’s no reason to allow for “only just enough” head space between tamped puck and screen. Provided your tamper/basket proportions allow for it, I would err on the side of more.

Love your videos as always!

[hopeimfunny]

This is big-brained "how did I never consider this before" stuff, thank you so much.

[lucafrattari]

Compelling story, a must watch beginners and aficionados. Thanks for sharing

[peterpan]

another very good point about temping... i learn so much already in this video than other coffee youtubers

[glen.moralee]

Thank you for this. So simple and yet I had no idea despite years of coffee obsession.

[unclekim]

Man, appreciate all the experiment you did. you are the best sir!

[naharidavid]

ive been thinking about this ever since I got a decent timed grinder (I got a specialita on your recommendation). I was surprised at how varied the volume and mass is between different beans. Now I know that when it comes to espresso, volume is the key to consistency. This is where timed grinders come in handy. If a new bean results in too much/little screen clearance after tamping, I can dial in/out a few tenths until I get it right.

[all_systems_failing]

I started paying more attention to headspace a few weeks ago after getting frustrated with trying to work within the basket's listed average capacity. Getting much better shots now. Thanks for your efforts!

[machineslave]

Real interesting video. I’m going to try this.

[chongli]

Definitely an advantage of e61 group machines where the shower screen is shaped like a jar lid. Other sorts of machines (saturated groups) have a shower screen which is just a flat disk with a hole in the middle for the retaining screw.

[prke]

Tamping Preassure does not affect shot time unless you tamp with insufficent force to cause channeling.

Main Reason for the tamping preassure being irrelevant at a certain point is that at 9 Bars a Coffeebed of 58mm Diameter will experience a Downforce equivalent of around 240kg.
Wether you Tamp with 20 or 40 kg barely makes a dent in comparison here.

This is an old myth that has been debunked quite alot of times. I can provide sources but YT doesnt like it when people post links.

[justinbouchard]

interesting way to say don't put too much coffee in your portafilter basket

[peterpan]

very good point.. the weight is different depending on the coffee

[cedric]

You say that coffee particles expands when water gets to it, making it possible for the puck to touch the screen. But when we look at an extraction in a transparent portafilter, it clearly appears that the coffee only expands after the shot, when the pressure is shut (which makes sense).

[TomJones-txpb]

Good points about tapered baskets.
I know that the density of my coffee beans tends to get less the more they are roasted. Also, different beans off-gas different amounts of CO2, absorb different amounts of water, and try to expand different amounts. That said, when I dose to the specced height/weight in my baskets, +1-2 gm of extra coffee makes little difference in the puck/extraction behavior. I often don't even have to weigh the beans, it is typically 3 spoons to within one bean for an 18gm extraction. I like having a dry puck after extraction without having to clean the screen much, so have various basket sizes in 2gm increments for how much coffee I want to extract (14-22g), and still get the effect Nich J is talking about.

[ninnyhammer]

Just got a new ECM Synchronica. With the bottomless portafilter and stock 22g triple basket, I mounded up 20g of coffee and put a coin on top (did not tamp). Locked in in and took it out. Put a straight edge across top of basket and used a digital caliber's depth rod to measure down to top of depressed coin. After subtracting width of straight edge, I get right at 1 cm. So in the future I know to have coffee bed height at least a few mm more than 1 cm below top edge of basket! Maybe I'll make a little wood block tool to be able to quickly test this after tamping. Thanks for the vid!

[eric]

Great video. Isn’t it easier to get a leveller, or tamper, that is spring loaded and can be twisted to different depths? These normally have markings on the side. Compensate for any puck screens, then set the appropriate height for the leveller/tamper. If the leveller/tamper doesn’t groom the bed, then add more volume. If the leveller/tamper sits above the basket rim, then reduce dose.

[Tass...]

So the Razor tool that Breville includes with their machines isn't something that should be dismissed then.