This may be weirdness I’m seeing just from my particular set up, but thought I would ask. I have a 9Barista, which means that the extraction just goes when the internal temperature/pressure hits 9 bars. Once it starts, I don’t have any real control over the extraction. My control over the espresso is primarily from the setting on my DF83 (stepless grinder) and the dose. I’m used to using 19g all the time, and adjusting the grinder setting to tweak things.
My experience is that a range of grinder settings over 5 tick marks or so gives me extraction times of 20 to 60 seconds, and if I go finer, then the 9Barista may choke, at which point the safety valve goes off.
With my current bag of beans, a grinder setting of 17 results in a 25s extraction, with 38g of espresso coming out. This setting is a little on the acidic side, with a little less body than I’d like. Still good, though.
My usual move here is to go a bit finer on the grind, and what I would expect is that as I go to 16, 15, and so on, the extraction time would go up by 3-4s for each tick mark, and the taste would shift as you might expect.
What has happened is that if I go the slightest bit finer than 17, the extraction time goes up by A LOT. In fact, it appears to me as if the coffee is fine enough that water isn’t making its way through the puck, and diverts out the chimney instead. The espresso that does come out is shifted in the taste direction I would expect, but the amount of espresso is considerably less, about 25g. I think that this is a result of some of the water going out the chimney instead of through the puck.
I know part of this is probably unique to the way that the 9Barista works, but it seems that with a conventional espresso machine, a small change with a stepless grinder usually results in a small change in the espresso. I think the analogous situation with a conventional espresso machine is having a small change on a stepless grinder setting resulting in a considerable difference in extraction time, if all other settings were kept the same.
Has anyone seen this?