I bought a nanotech baristapro basket from IMS, hoping to see an improvement in my shot and a better tasting cup. The basket runs faster than my stock basket, meaning that I need to grind finer with the same beans. The difference between too fine and not fine enough, is very small with the baristapro, it’s way too unforgiving. I’m left judging the tamp pressure, to account for the aging of the beans, and missing the relative consistency of my old stock basket (I still have that of course, just trying to make this one work). The best cup I’ve had with the baristapro was ‘maybe’ better than my stock best, but not entirely sure (as beans change of course). I’m left now, having used it for a few months, frustrated at the inconsistency caused by the frequent channelling (something my old basket never suffered). I think the increased fine grind has itself actually added to the channelling - as the pressure to penetrate the finer puck forces channels, looking for the path of least resistance. If I grind more coarsely, the short is under-extracted and runs out in too short a time. Has anyone had consistent success with this basket?
Haven’t used an IMS basket, I only use VST so I can attest to those. I don’t have any shot-to-shot consistency issues and overall my brewing experience with them has been phenomenal. Your tamp pressure is likely not changing anything, unless you are not fully tamping to begin with; either you get all the air pockets out or you don’t—additional pounds of pressure do not really change much after this. Is your grinder step-less? Ensure you are able to grind at very fine intervals, otherwise this could be your issue with the IMS basket pulling faster while your grinder cannot perform consistently.
I’ve ground so fine that the shot will barely drip out a few ml over a whole minute. Dialing back, I get to a place of optimality, time-wise (17g in 35g out in around 30-35 secs). The problem is that I can definitely see channelling, one area will run faster while other areas will run more slowly, leading to over and under extraction (the colour and speed of the flow is very obvious). I’m using a mignon and I’ve checked that the burrs are perfectly level, I don’t have the large adjuster wheel though. I get little to no superfines, just a propensity to channel, too often to be acceptable. With the beans aging (and changing every two weeks) I am adjusting the tamp pressure to try to avoid channelling, as it appears that finer grinding is leading to more channelling, to overcome the density of the compacted puck? I will try to minimise any other affecting factors as best I can, and see how I get on. Thanks for all your input guys.