This is a question we get all the time. Something like, “I’ve got a Baratza Virtuoso Grinder. What settings should I use for press, drip and espresso?”
Wouldn’t it be nice if we could just say, "oh, that’s easy use a 3 for espresso, 20 for drip and 30 for press?" Unfortunately, even though most burr grinders have some reference numbers for grind size, the problem is they don’t transfer between grinders. So you can’t just say, if you have grinder “X” you should set it to such and such number for making drip coffee. This guide will help you zero in on the proper grind size depending on your brewing method and learn how grind affects flavor.
Between the same make and model of grinder, calibration can be different or the burrs might be more worn so those numbers don’t transfer. Even if they did, the grind size that makes what you consider the perfect cup might not be the same for what we consider the perfect one. The best we can do is visually compare grind sizes and make some basic suggestions about what particle size works for different brew methods.
The finest grinding is used for Turkish Coffee. Call it extra fine, extremely fine. In fact, when making Turkish coffee the finer the grind the better. It should be almost as fine as baby powder.
Moving up in size, for espresso and Moka pots you want a fine grind. A good starting point is something just a little finer than granulated sugar. Grind size for espresso is perhaps the most critical of all the brewing methods. Tiny changes in grind size make for big changes when pulling shots. And that’s why espresso lovers are very particular about their grinders.
Now we’re into the medium grinds. This is the range for drip coffee and brewing methods like pour over, siphon and vacuum brewing.
A couple tips for medium grinds: first, for methods using a filter like drip and pour over, use a finer medium grind for cone shaped filters and coarser for flat bottom filters. Second, you can use grind size to make subtle flavor adjustments. If your cup is a little bitter, grinding coarser can help correct for that.
Moving up again, we’re into a coarse grind used for French press coffee. What you’re looking for is something close to or maybe a little smaller than a coarse salt for particle size.
Our last grind size is extra coarse. It’s what you want when making cold brew and follows a basic principle of grind size which is: the longer water is in contact with the coffee the coarser the grind.
In cold brewing, coffee is in contact with water for 12 hours or more. That’s opposed to a fine grind for espresso with a pressurized water contact time of around 30 seconds.
A couple of final thoughts on grind: always grind as close to brewing as possible, and invest in a quality burr grinder. Stay away from blade grinders. Blade grinders hack up coffee into randomly sized bits ranging from dust to chunks, making it impossible to get consistent particle sizes and leading to uneven extractions with poor flavor and muddy cups.