A couple of weeks ago, I decided to be adventurous and attempt a SO espresso. My usual beans are a blend from my local roaster (equal parts Mexico, Colombia, and if I remember correctly Guatemala). This time I bought a half pound of Colombian. When I got it home and followed my identical technique that was giving me tasty shots with a brew ratio of 2:1 in ~30 seconds, I got an extremely fast pour. 60g output in around 10 seconds. I did what this forum recommends with a fast pour: I tightened my grind as fine as my vario would go at 1A from 1F. I expected to choke my Carezza, but the pour looked the same. I googled my problem and found a thread on HB in which Kyle from Baratza said lighter roasted SO beans may require a much tighter calibration, so I tried that. Instead of my motor beginning to labor at a few micro clicks above 1W, it was now laboring as soon as I switched the macro from 2 to 1. Not intense laboring, but a noticeable change in the motor sound. Anyway, back to 1A, 14g of beans in, and another extremely fast pour. This time it seemed just a bit slower, but still a sink shot. I settled on just brewing the rest of this coffee since it was so delicious and going back to my usual beans for espresso. I then recalibrated my Vario back to how it was before.

This is where I'm utterly confused. I just got more of the espresso blend from the local roaster, and now every shot from these beans is also very fast! I could tell by watching the grounds come out. Using the same grind setting and time, I got 3 more grams of coffee than I did before. This morning I tightened the 2mm allen screw tight enough to where the grinds were barely coming out on 1A and clumping more than before. Same result in the cup.

I am perplexed as to what the problem is. The last shot was ground obviously finer than what used to give me great pours. I'm doing the identical puck prep (WDT, light tamp, NSEW, heavy tamp, light polish), and identical espresso machine prep (warm up for half an hour, flush ~2oz of water, temp surf with steam switch to get to a good brew temp, lock PF, pull into warm cup), and the puck after the pour shows no signs of channeling. It does look like it wasn't bothered as much, though. Before I could clearly see dimples where the water was coming through most from the shower screen and a bulge where the shower screen screw is. Now it looks basically flat. I'm pretty sure I can rule out the beans as a culprit (roasted 4 days ago, same blend that worked before), so that just leaves my grinder, technique, and machine. Any help would be immensely appreciated.

This is probably a slam dunk for kyle at baratza, send them an email.

My bet is the belt or set screw is loose/needs to be tightened/replaced

I used to have a vario, and would switch between light and dark roasts on a regular basis. The darker roasts were set to work around the 2F-W mark (would vary), and some would go as coarse as 3A-F (there's some overlap but...). I forget if laboring was set at middle of 2 mark, or, at bottom of 1 mark.

When switching to lighter roasts, results were best by grinding beans while adjusting finer, and let it go through about 6-12g when you reach your stop. Each time you go finer from there, make sure you have the grinder running with beans. It's a little wasteful, but it's worked for me.

jedovaty wrote:When switching to lighter roasts, results were best by grinding beans while adjusting finer, and let it go through about 6-12g when you reach your stop.

Okay. So I tried this. Emptied my hopper and went back to the bottom on the micro adjustment. Slowly while grinding I moved up to 1A (probably went through 10g of coffee). The shot I pulled with it was actually not terrible. It was lungo (about 45g before blonding), but drinkable. Before I started having problems, I would get results like this at about 1H to 1J. Now it's at 1A. Very bizarre. Apparently I just need to calibrate my vario quite a bit finer. I have no idea what I did to it to throw it off so much.

EDIT: Decided to do a primary calibration on it. Emptied the bean hopper and adjusted the 2.5mm screw all the way as fine as it'll go. I probably made the grinder TOO fine, but I'd prefer a lot of head room especially since I've never come close to 10. I'm over-caffeinated today, so I'll post back the results tomorrow. Would it hurt the Vario to be adjusted too fine if I never actually run it at 1A?

Just a FYI. Did it get excessively humid lately? I always seem to recalibrate my Vario in the middle of summer.

Hey, I did forget to say, I calibrated mine so the lighter roasts would give me shots in the 1f-w range, while darker roasts would be 2-3 + letters. Basically, offset one or two major spots from the calibration technique they mention in the manual.

I think you caught onto that though If this is working for you with the extra grinding, then, remember, it's after you reach the stop point. Once you've got it dialed in, should be good for those beans for a few days. The darker roasts aren't as finicky, and from what I remember, didn't need this kind of treatment.

jedovaty wrote:I think you caught onto that though

I did. Resetting the calibration fixed it! I'm still not quite sure what threw it off so suddenly, but at least I'm back in the "good" range.

Thanks guys,
Matthew