another_jim wrote:Personally, I don't think the leveling method is accurate enough. Even in the best cafes, with well trained Baristas, one sees various combinations of 7 second time and 25% volume variations.
This is just not true among good baristas and indicates a bar that has long been since exceeded by top companies.
When I was working professionally full time I could dose by volume 10 straight times with variance (by weight) of less than 0.3g. This was, in fact, a training test originally introduced to me by Aaron de Lazzer and later adopted.
If on the bar my shot time was off by more than 2s (ie less than 10% variance) I would either chuck the shot and re-pull (if I thought it was a dose issue) or chuck the shot and adjust the grind.
And to be clear - at Stumptown I was an average barista.
Dosing by volume with practice is feasible, accurate and efficient.
It is not - to be clear - something I would recommend to most home baristas as the "with practice" assumes a lot more practice (and coffee) than is economical (or realistic).
But saying that it cannot be done in a bar scenario is untrue - and saying that "well trained" professional baristas accept variance of 25% in extraction is even more untrue.