i've been cruising along with my virtuoso getting predictable results from the settings - until today. no matter how i adjusted the grind, my espresso came out too fast. in desperation i did the same bean - espresso monkey, city + - in my Zass and that wasn't any better.
i checked the grinder, cleaned it and reset the burr. only a few clicks away from metal contact still gave a lousy pull.
the coffee was barely 24 hours post roast, and a much lighter roast than is usual for me. could the age of the coffee- relatively young - or the roast effect my results this much or should i look elsewhere for my problems?
Steve

Degree of roast, bean type, age, weather, your mood... these all effect the grind.

Burr contact (rubbing) is not a problem for good grinders, and should be a perfectly reasonable place for your espresso grind setting.

Yes. Very light or very dark roasts require finer grinding since they produce fewer fines. Also, for the first 48 hours or so, coffees are extra gassy, so the same flow looks thicker and faster on a naked PF.

Yeah, I agree with Jim. There have been times where I roasted coffee too late, and had to use coffee earlier then I would've liked, say as little as 24hrs, like you did here.

Regardless of grind or dose, even stuffing 26grs in a LM Straight-Sided Triple basket, with a grind that would normally choke the machine fully, I would get nothing but 20 second gushers, some yielding 3oz or more. Not to mention the cone was HUGE, and formed almost instantly.

Even if it is a light roast, a few days rest should help you out a bunch.

i think humidity may also have played a role. we've had stinky humid weather, dew points well up in the 60's and now we have very cool, dry air.
anyway, i dialed back to contact and then let it out a little and i'm happy again.
so is it true that as long as there are beans to lubricate the burrs, grinding at some degree contact is ok?