Unfortunately, I was not able to dial this blend in before finishing the bag, but I have a theory as to my problem.
I narrowed it down to the first 1/3 of the pull as the culprit for the sour acidic taste. I believe that portion was under extracted due to the VPT, i.e. opening the steam wand during the initial extraction caused the pressure to be too low, hence the sour taste at the bottom of the cup.
Overall, I think this technique maybe an answer to a problem that doesn't exist. The vibe pump ramps up so slowly, it acts as a natural preinfusion I think.
Anyhow, I pulled some shots of home roast SO Ethiopian Haile Sidamo today from SM:
- 11 days post roast, FC+
- ~14g
- ~203F
- 1.5oz in ~27 sec
Chocolate and spice bomb!! Not what I was expecting from the description, but tasty none the less. Highly recommended!