Just to revisit my original question, here’s an example of what I’m seeing with my Baratza Virtuoso+ and dosing. This is all with a 9Barista in terms of the effect that changing the grind setting and dose have on my espresso.
This Post-It has my notes as I’m dialing in an espresso made with a bag of beans I’m trying for the first time. We can ignore the top line. In case you can’t read my chicken scratch, the first attempt is grinder setting 7 and 16.0g, which resulted in a 15s extraction time. The entries are:
- Grinder 7 - 16.0g, 15s
- Grinder 6 - 16.0g, 22s
- Grinder 5 - 16.0g, blocked
- Grinder 7 - 19.0g, 20s
- Grinder 6 - 19.0g, 35s
- Grinder 6 - 18.5g, 30s
The extraction time correlates pretty well with what I think about the range of flavors in an espresso. The shorter the extraction time, the less rich and more bright/sour the espresso gets, and the longer the extraction time, the more rich and strong/bitter. The two shots that were 20 and 22s were okay, but the ones that are in the 25-35s range were very enjoyable, and the last one at 30s was fantastic. That’s been my experience with the 9Barista regardless of the coffee beans I use.
As you can see, a single click on my grinder results in quite a big change in extraction time if the dose of coffee is the same. For example, at 16g, going from 7 to 6 is a 7s change in extraction, and at 19g, going from 7 to 6 is a 15s change.
On the other hand, what I think are fairly significant changes in coffee dose (0.5g) result in less of a change in extraction time (5s at grinder setting 6).
Another example — at grinder setting 7, going from 16g to 19g is only a 5s change in extraction time. At grinder setting 6, the same dose change results in a 13s change in extraction. This is on the order of a single click change on the grinder, but a 3g change in coffee dose is pretty big by anyone’s standards.
Again, using this approach (using the grinder to get close, then adjusting the dose to fine tune) I can get espresso at least as good as any coffee shop in my area, and that are as good the best cups of espresso I remember having. But I think it’s clear that I have less fine control over the espresso with my current grinder than I do by adjusting the dose.