Materials and design of grind adjustment mechanism. Plastic burr holder design is seriously flawed and cannot withstand the stress of a fine grind.
I purchased a refurb Baratza Maestro Plus in Oct 2007. It is a latest incarnation after the mid 2007 redesigns (3 tabs instead of 2, beefier adjustment ring tabs, silicon seal, anti-static bin). I purchased it for both espresso and auto drip use and was assured by Baratza that it was more than capable of a fine espresso grind and the reviews here indicated that this was indeed possible. I am using an old Estro Profi (Starbucks Barista) with a Solis NP Portafilter, which is actually capable of decent shots with a fine enough grind.
I was just able to pull a decent shot using the Maestro Plus set at the absolute finest setting, but this required super fresh beans, overdosing and overkill tamping pressure. I tried to adjust the grinder myself as per Baratza instructions but found that this machine had already been adjusted to its limits. Joe at Baratza offered to send me a 'finely calibrated' replacement and even sent a prepaid UPS shipping label for the return. Wow, what service!
The new grinder arrived and indeed was set much finer, too much so actually as the burrs started to 'touch' at setting 10. I was able to grind some decent shots but still not great or predictable. I also noticed that the hopper seemed looser than the first one and removed the cover to give the insides a look over. I found that one of three mount points for the motor assembly was broken off. I couldn't stand going through the return/replacement thing again and being handy glued it back together with polyeurethane glue. Better than new actually.
Next problem arose a few weeks later when the grind adjustment became very stiff and the motor would halt with a bean stuck in the burrs. I found that the plastic ring that holds the top burr had cracked at one of two weak points along the top. It seems that fine grounds had worked their way between the burr and the plastic and ultimately cracked the plastic ring open. Another call to Joe at Baratza who dropped a new ring to me in the mail. Wow, great service again! This worked fine until today when the new ring cracked again in the same place and same way, less than one month and light use, later, most of which use was for drip grind.
I quit. This grinder is simply not up to doing an espresso grind. All of my attempts have resulted in machine failure. I will note that it did perform reasonably well for a medium-fine drip grind and would make a fine grinder for that use. I simply do not understand how they can honestly market these grinders for espresso use, it is not up to the task.
I now have to decide between the $300 Rancilio Rocky to replace this thing outright, a $500+ dedicated grinder together with this piece of crap, or some other option... Help!
Great. Baratza service is really excellent for purchasing and repair as many have noted. Too bad about their product.
Three Month Followup
Well its actually been 6 months, oh well. Since this review I purchased a Rocky Doserless and am extremely pleased. I also contacted Baratza to simply get a replacement top burr carrier, but Joe insisted on sending me another Maestro Plus along with the prepaid return shipping label. Well that one arrived and to my dismay it had an extremely loud motor. I pulled the new top burr out of it and sent it along with my broken top burr straight back, along with $20 to partially reimburse Joe for his extremely generous trouble. In the end, Maestro Plus number two is simply taking up space in my pantry waiting to do back up duty for the Rocky. Maybe I should take it to work to enjoy fresh ground coffee on the job....