Everyone knows to take care of their espresso machine and yet most people overlook one of the most important stops along the way to a good cup of coffee--the grinder itself! When dirty, your grinder will be more likely to clog or jam, doubly so if you're using dark roasted beans! If the buildup is severe enough, your grinder may start to grind your coffee less consistently. Your particle size distribution, a method of measurement in which the number and size of the ground coffee particles are recorded and plotted, may begin to diverge from it's normal setting. Practically speaking, this means that you'd be more likely to experience channeling and you may notice an increasing amount of variability in brew times from shot to shot. If you're doing a good job of distributing the coffee grounds in your portafilter and you're using the same amount of coffee each time, yet one shot takes 15 seconds to brew while the next takes thirty--you should clean your grinder.
For most home users, I'd recommend that you clean your grinder every six months. Half that if you use a very dark roast or if you're using the grinder for both espresso and drip. This is a general estimate, so keep an eye on how much accumulates between cleanings--you may find that you have to adjust your cleaning frequency one way or the other.
There are a number of people that recommend using rice, steel cut oats, or corn grits to clean their grinders, and while these are fine for blade-type coffee grinders, I cannot condone their use for burr grinders. Rice, in particular, is much harder than either coffee or cleaning tablets meaning that it is more likely to dull the sharp edges of your coffee grinder over many repeated cleanings. This reduces the life of your burrs, and makes channeling almost a certainty. All of these home alternatives are more likely to get stuck in the grinder. Days after cleaning, you may still be finding little bits in your coffee. Any damage to the motor as a result of using improper cleaning supplies is considered misuse of the grinder and is not covered under warranty. Rather than risking all of that, I'd recommend that you just use the stuff made specifically for what you're trying to do.
To clean your grinder, I'd recommend using the Full Circle Grinder Cleaner. It may be more expensive than other options like rice, but it's still cheaper than new burrs! Even if you're cleaning every three months, a can of the stuff will still supply you for 3 years of cleaning!
- Empty the hopper of your grinder
- Grind through the remainder of the beans in your grinder
- Measure out one capful of grinding tablets into your hopper
- Run the grinder until nothing more comes out of the spout
- Using an air-duster or a can of compressed air, force some air down into the burrs to try to remove as much of the grinding tablets as possible
- Using some old stale beans, grind a few shots worth of coffee through the grinder to ensure that all of the tablet residue is gone. Since we don't want to actually brew coffee with this, it's okay to use old beans or cheaper beans that we wouldn't want to drink anyway
- If there is a lot of oily buildup on the hopper, separate the hopper from the grinder
- Wash the inside of the hopper with water
- For stubborn residues, use a food-safe degreaser to loosen the oils before scrubbing with a soft sponge. Most hoppers are soft plastics that will scuff easily if you use a brillo pad or kitchen scrubby, so beware!
- Allow the hopper to dry completely before putting the hopper back on the machine
For very relentless oil buildups between the burrs, it sometimes becomes necessary to separate the burrs and remove the upper burr carrier from the machine entirely in order to clean manually. Done wrong, this can cause a lot of (expensive) damage to your grinder. If the wrong lubricant is used when threading back together (or none at all, which is worse!), then you risk cross-threading the carrier or allowing it to seize later on. For some grinders, this would cost almost as much to fix as it would to replace it with a new grinder. For this reason, if you believe that you need to separate the burrs, please contact our Service Department for more help. We can be reached by e-mail at firstname.lastname@example.org or if you call Monday through Friday from 8:00am to 5:00pm EST, at 518-452-5995.