Literally Everything You Would Ever Want to Know About Burrs (Seriously.)

There’s no question that the largest investment on your brew bar should be your grinder (more about that later!) There are many factors to consider when purchasing a grinder – in fact, we wrote another blog post on how to choose a grinder!

We wanted to focus on one aspect that we’ve had a ton of inquiries about, and it’s all about burrs. When we say that “the grinder does all the work” in your coffee flow, what we really mean is that the adjustments you make to your grind size is the main variable to getting a dialed in shot. And what’s the thing that turns whole beans into grinds? Your burrs. 

So without further ado, let’s talk about the type of burrs you might find in a grinder, the material, the geometry of the design, and common substitutions people make for our most popular grinders (and why!)

What are the different types of burrs?

• Flat burrs, which have two rings that sit on top of one another (one faces upwards, the other downwards). Beans drop between the burrs, grind through the first burr, and then drop again. 

• Conical burrs, which have a cone-shaped ring that sits in another hollow cone ring, allowing the beans to funnel through the burrs in a vertical pathway.

• A special mention goes to blade grinders (also known as propeller grinders), that chops beans into smaller particles using a spinning blade

So, Coffee Addicts, which one is better?

We will never tell you which one is the best, because that’s totally up to you! What we can tell you is what to expect out of each burr design, allowing you to choose the best grinder to fit your needs. 

Blade grinders are an advantage for many home baristas due to their accessible price point and versatility, meaning that you can use it to chop your beans and your spices. It works by whirling the blade around an axis, which means that depending on where each bean is placed in the hopper, you may get bigger or smaller grind sizes. If you’re someone who loves making a French press or drip coffee, this might be a good advantage for you as these brewing systems don’t require a super fine grind. 

Conical burr sets produce different variations in grind size, which isn’t always a bad thing. As the beans move down the grinder, they produce a mix of smaller and larger grind particles; some folks might point out that inconsistent grind size is a bad thing, but in this case, the inconsistencies may produce a more preferable taste. 

Flat burrs produce the same grind size across the board, with one burr fixed to the unit and the other able to move closer or farther apart. As the beans move through the center of the burr, the centrifugal force draws the grinds from the center to the edge of the burrs, resulting in a uniform grind size. 

So, does consistency matter? 

The conical burrs produce more of a bimodal distribution, meaning that many grind particles are one size (let’s say larger) and other grind particles are a different size (let’s say smaller). Flat burrs produce one grind size, so would be considered a unimodal distribution. 

In conical burrs, the smaller grinds regulate and diversify how water moves through your coffee; flat burrs ensure the rate at which the water moves through the coffee is the same depending on how fine you grind your coffee. Remember: your espresso is a result of how the water dissolves the grinds, so it depends on whether you’d like to have a more complex espresso, with a blended flavour and more body (which equals variable grind sizes, which results from a conical burr set), or more separation of flavour, with a clean taste and easy reference to dial in (which equals the same grind size, which results from a flat burr set).

Mind = blown, am I right?

What about the material and design of those burrs?

Material also matters, and this is where most people come down with a case of “upgrade-itis.” As it turns out, there are more than a few materials your burrs can come in (go ahead and google it, we’ll wait…) We’ll talk about some of the most common, and then the different upgrades that are offered.

What’s the difference between commonly used burrs, such as plastic, steel, and ceramic?

Plastic burrs are used in very accessibly priced grinders; however, they don’t tend to last as long as other burrs materials on the market. Steel burrs are the most common for any home grinder; they are sturdier than ceramic and plastic burrs, ensuring you can make consistent coffees for a long time. However, compared to ceramic, titanium, and red speed burrs, they have the shortest lifespan, retain more grinds, and can build up heat much quicker (which isn’t advantageous as excess heat takes away aroma and taste from your beans). Ceramic burrs last longer than steel and plastic burrs, have a lower rate of retention, and less heat than metal alternatives. However, the material is quite fragile, meaning that foreign objects found in your coffee beans can easily damage the burrs. 

Okay, let’s move onto the upgrades: Titanium, DLC, and Red Speed.

Seen mostly in commercial-level grinders, these burrs are steel burrs with a material coating and are incredible due to their enhanced durability, longer lifespan, and reduced heat generation. These are considered life-time burrs, leading to more consistent grinds for longer, and can produce a more flavourable coffee that is definitely noticeable. Titanium burrs are typically made with a steel core and a titanium coating, and last up to 3-5x longer than regular stainless steel burrs, reduce heat generation (meaning a more tasty cup), and maintain sharpness for longer, ensuring consistency with flat burrs. Titanium burrs often have different names, such as Nuova Simonelli’s Mythos burrs. DLC burrs have a carbon-based coating on a steel burr, mimicking some properties of diamonds. The result? An extremely hard and smooth surface, making it exceptionally durable, with a high resistance to wear, and has less friction (reducing heat buildup). Red Speed burrs are similar to titanium, but are steel burrs with a titanium/aluminum nitride coating, which is similar to what is used on industrial drill bits. More durable materials means you can take everything we said about Titanium burrs and multiply it by 2, making it even more durable. 

What about burr size?

The bigger, the better (in our opinion). We spoke about the importance of aroma and flavour, and how heat impacts that. The less your grinder has to work, the less heat and friction there will be on your grinds, which results in a pretty tasty cup! One way a grinder can affect this is with its burr size; the bigger the surface area, the faster your dose grinds with less “work” put into it. 

Further to that, what about the burr geometry?

Burr geometry refers to the overall design of the burrs themselves, with a teeth pattern/cutting pattern that determines how coffee beans are fractured during grinding. Relating back to our unimodal and dimodal particle size, different burr geometries can produce different grind size distributions. The geometries are also optimized for specific brew styles, such as espresso or pour over (traditionally). The geometry also relates to alignment sensitivity; espresso burr sets are much more sensitive to misalignment than burrs designed for coarser grinds.

Want your burrs checked for alignment? Our service department handles that! Click here for more information, or send us an email at service@coffeeaddicts.ca

And there you have it; quite literally everything you’ve ever wanted to know about burrs (from what I can find). Have additional questions? Pop them down in the comments or send us a message and we’ll answer them!

Happy Coffee-ing!