If you've been drinking coffee long enough, you probably have your routine -- a favorite method, whether that's drip, espresso, or pour-over and a small collection of tools to match. But the brewer is just one piece of the puzzle. What ends up in your mug is shaped by a handful of factors, and one of the most overlooked is grind.

Getting the coffee-to-water ratio right matters -- experts point to a golden ratio as the target -- but grind size is just as consequential. Too coarse or too fine, and even great beans fall flat.

Most experts recommend grinding fresh at home, but not all grinders are created equal. The best ones produce a consistent, even grind that gives you more control over the final cup. That means a burr grinder.

What is a burr grinder, and how does it work?

Unlike a blade grinder, which grinds coffee beans by slicing them, burr coffee grinders crush them. Burr grinders use two abrasive or notched discs or plates, known as burrs, that rotate either parallel to one another or concentrically.

"A burr grinder gives you maximum control," Kaleena Teoh stresses. Teoh is co-founder and director of education for Coffee Project New York, and praises burr grinders for "giving you the power to brew the coffee exactly the way you want it to be."

As the coffee beans are squeezed between them, they're crushed to a preset size determined by the distance between the two burrs, which is adjustable to suit both the type of coffee being made and personal preference.

Why a burr grinder is better than blades

"With a blade grinder, there's no way for us to guarantee how the beans move within the grinder, which essentially works like a blender," says Teoh. "You're basically cutting and chopping the beans at different angles," as they fly around haphazardly within the chamber of the grinder. 

No matter how long you run the grinder, you're still likely to get a wide variety of particle sizes in the finished grind, "from really fine powdery sizes to really big boulders in there," she says.

By comparison, the primary purpose of burr grinders is consistency, as the grinder's shape forces beans to move between the burrs in a specific manner. (One of two specific ways, outlined below.) "You'll always have slightly different particle sizes," says Teoh, no matter what kind of grinder you use, "but for the burr grinder, that range is way smaller compared to a blade grinder."

Flat burr grinders vs. conical burr grinders

Burr grinders come in two forms: flat burr grinders, where the two ring-shaped burrs are stacked on top of one another in a parallel fashion. Beans are then inserted into the inner circle and are forced between the burrs before emerging on the sides. Conical burr grinders consist of one ring-shaped burr, and one conical burr, which work concentrically, with the beans passing between them and coming out through a chute below.

Read more: The Fellow Ode Brew Grinder Is a Fantastic Gift for a Coffee Snob

"Both flat burrs and conical burrs are able to give you great results, says Teoh, "as long as you're able to understand how to dial in the grind for your coffee." 

Burr grinders of either style may be pre-calibrated for specific coffee styles, such as pour-over or espresso, or may offer a wide range of grind sizes. However, all will be adjustable, allowing you to fine-tune the grind to achieve the flavor you want in the finished brew.

There is a slight difference in particle size distribution between flat and conical burr grinders, which mainly comes down to a matter of preference. "A flat burr gives you a grind where the majority of particles after grinding will be a consistent size, and with a conical burr, it gives you two sets of grind sizes, with one group that is slightly finer and one group that is slightly coarser," says Teoh.

The argument for a conical burr grinder is that it gives you a more complex shot of espresso because it allows two different extraction rates; however, "the Specialty Coffee Association did a lot of research and blind-tasting and determined that it's very difficult for people to tell the difference."

The key to choosing a burr grinder is to select one that matches your use, as some burr grinders are pre-calibrated to produce a specific range of grounds for a particular style of coffee: extremely fine, powdery grounds for espresso or large, sea-salt-sized grounds for pour-over or French press. Some burr grinders offer a wide range of settings for various types of coffee.

Burr grinders: Good brands and average cost

Burr grinders come in either electronic or hand-crank models and, like any kitchen appliance, you can spend a lot of money on one, but you don't necessarily have to. Teoh says she uses a variety of different grinders with Coffee Project New York; among the professional brands she likes, such as Mahlkönig and Victoria Arduino, there are several she recommends for home use:

• Fellows Opus conical burr grinder: $200
• Baratza Encore coffee grinder: $120
• Hario Skerton Pro ceramic coffee mill: $52
• 1Zpresso manual coffee grinder: $139

The beans also matter

If you're thinking of getting serious about the burr grinder, you should also get serious about the beans. Your average supermarket whole beans are probably not worth the splurge. Notably, for burr grinders, especially hand-crank models, the darker the roast, the more brittle it is and the easier it is to grind. Therefore, factor in your preferred roast when making your buying decision.

As far as optimizing consistency and control with a burr grinder goes, "buy coffee from your local roasters," advises Teoh. "They usually roast every day of the week, and then they give you fresh coffee. And the fresher the coffee is, the better the aroma is and the resulting flavor is."