Blue Bottle Explains: Coffee Grinding

Coffee is not an obvious beverage.

Coffee is not an obvious beverage. It doesn’t help you recognize its goodness. You literally have to pummel and crush it into tiny particles to discover its potential. Pretty dramatic, huh? We call this process grinding—and it’s basically impossible to enjoy coffee without it.

I spoke a bit about how to work with grinding in a previous post about bitterness, but now I want to address the overall grinding process. Grinding breaks whole coffee beans into small particles to give the water access to the good stuff in the beans, which ultimately gives us access to the good stuff in the cup.

Pretty simple, right? Not really. 

There are two aspects of grinding that are crucial to making delicious coffee and that can be tricky to get right: Grind quality and freshness. 

Grind Quality

Grind quality is defined by how consistent a grinder can make those little particles. 

A blade-style grinder does a very poor job at this, creating some really large pieces and some really small pieces. This can lead to both bitter and sour flavors coming out of a coffee at the same time. 

Burr-style grinders are your best opportunity to get the most out of a coffee, because they create similar-sized particles. (I am a big fan of the Baratza Virtuoso). Not all burr grinders are created equal, though, and small home grinders can’t compete with large, industrial grinders. 

To make things even trickier, how you grind your coffee is entirely dependent on what kind of coffee it is and how you are planning to brew it. Every morning, in our cafes, our baristas “dial in” the coffee, meaning that they adjust the grind to get it exactly right for that particular coffee in that particular moment. This changes on a daily basis—there is no master key. 

At best, this is a coffee lover’s opportunity to tinker and explore. At worst, this is a science experiment before the break of dawn, before you've had your coffee. 

Grind Freshness

Freshness is a pretty simple matter. Once the coffee has been roasted to that quintessential chestnut brown, a clock starts ticking. That’s the freshness clock. When it runs out, so does your opportunity for the maximum joy that can be received from a cup of coffee. Even more troublesome is what happens when the coffee has been ground—that clock starts ticking at hyperspeed. 

You know that amazing fresh-ground coffee smell? You know how when you smell it you can almost see it emanating out of the cup because the aroma is so enticing and alive? That’s your coffee’s flavor dissipating into the atmosphere. This happens at such a rapid clip that the coffee will have lost a significant amount of oomph minutes after exposure to air. 

Having a grinder at home helps you keep the magic alive because it enables you to grind the coffee right before brewing, getting the most freshness and flavor possible out of every cup.