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One response to “#Coffee: #JamesHoffman video on RDT / Ross Droplet Technique for #Espresso, with bonus idea: spritzing the puck /cc @jimseven”

1. 2021/01/26

   alecm

   https://www.reddit.com/r/espresso/comments/l5p0z8/sharing_for_anyone_who_needs_it_using_rdt_in/

   So for a couple of years I’ve been using a tiny, cheap spritzer bottle to RDT my beans on occasion, mostly to stop my Baratza Virtuoso retaining grind; it certainly helps with that, dropping (with a bit of tapping) the retained grinds to the 0.0 to 0.5g range, as opposed to 1.5+ on occasion.

   But then the divine JH posted a video (https://www.youtube.com/watch?v=D8zqp3CgcbA) which suggested spritzing the puck after tamping, noting that this helped with pressure. This really interested me because my 2019 Gaggia Classic has a habit of making the first shot of the day very good (20g VST ridgeless, bottomless) – and then on the next shot it will either channel heavily – making a spritzy mess of the cup – or even it may clog solid and not pour.

   I’m constant with my grind, the bottomless portafilter and the VST helps keep my tamping sharp, same beans, so the only variable I can see with this second-shot problem is that the machine has had its first thermal cycle of the day and the water may be, perhaps, cooking-and-clogging the puck with an instant, hot infusion?

   I am not sure about this analysis, but the observation that I want to share is that RDTing the beans and then thoroughly and lightly wetting the top surface of the tamped puck with a spritzer has broken this pattern of behaviour. If you are seeing similar, give it a try.

   As JH notes, this (excessive RDT dampness) may not be wise in a commercial setting where grinders may get clogged up with wet beans, or where puck-spritzing eats time, but for fellow nerds at home it may be a game-changer. [edit for clarity]

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