SUMMARY: Grinding at home is critical for delicious coffee, and let’s assume you already know that burrs beat blade grinders. However, the many grinder designs and prices make it difficult to choose the right one. If you’re comparing flat and conical burr grinders, know that conical burrs tend to be more cost-effective and better for espresso while flat burrs tend to be more expensive because of their more uniform grind size preferred for filter coffee methods. However, there is complex science and more sublte differences to know!
Whether you are interested in buying a new grinder or just a coffee lover curious to upgrade your knowledge, I decided to write a short post clearing up the confusion between flat burrs and conical burrs.
Besides the basic definitions, I dive into the nuances of each grinder design so you can learn how they work and which brewing methods they excel at. I cover:
- The fundamental differences between flat and conical burr grinders
- Cost-effectiveness and brewing methods suited for conical burr grinders
- The consistency and grind precision offered by flat burr grinders (plus bimodal vs. unimodal grind distributions)
- Operational factors such as retention, noise, and maintenance costs
So, continue reading to upgrade your coffee knowledge and/or better decide which grinder type suits your brewing needs!
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Flat vs Conical Burrs: Understanding the Basics
The main differences between a flat burr and a conical burr grinder lie in their design and grinding patterns. Flat burr grinders have two parallel rings with serrated edges, and you adjust the grind size by changing the space between these two rings. Conical burr grinders consist of a cone-shaped burr fitting into a ring burr. Gravity plus the spinning cone pull the beans down, and the grind size becomes finer as you adjust the cone tighter into the ring.
Do these specific designs matter? It turns out that the unique design difference between conical and flat burrs affects the consistency of the grind, the cost, and the unique type of extraction they create. Plus, if you are using them in a commercial setting, differences between heat output and maintenance can also be a relevant factor.
Which Is Better Flat or Conical Burr Grinder?
The debate between flat and conical burr grinders is less about which one is plainly better since they each excel in specific circumstances. It is more accurate to think of each design as offering unique benefits and challenges that cater to different preferences and brewing techniques.
The primary differences include:
- Conical burr grinders are typically preferred for their affordability and less complex design, suitable for entry-level users and manual grinders.
- Flat burr grinders are favored for their consistent grind sizes (more on why later), which are especially beneficial for filter coffee lovers seeking uniform extraction and flavor clarity.
- Those passionate about espresso might lean towards conical burrs since the bimodal grind (more on this below) can enhance body and texture, an extra-important factor for espresso shots.
- Grinder design factors such as retention and noise are not intrinsically tied to the burr shape but are integral design considerations.
- Conical burrs generally run cooler, which might be a factor in commercial settings.
Features:
- Flat Burr Design: New Gen 2 Brew Burrs produce a sweet, balanced, complex cup with tons of clarity.
- 31 grind settings for drip, French Press, AeroPress, Cold Brew, etc
- New anti-static technology reduces grind retention
- High-quality materials = quiet grinding
Which Burr Is Best for Espresso?
To be clear, both conical and flat burrs can work with espresso, and many coffee professionals disagree on which is better. While so much in specialty coffee is scientific, a lot comes down to subjective preference in taste, ie, which aspects of the coffee extraction do you wish to highlight?
In my opinion, since delicious espresso relies so much on texture and body, conical burrs win the debate. Especially if you are making milk drinks, the enhanced mouthfeel balances well with the sweetness of the milk, something that the highlighted acidity might not do.
Features:
- 6-blade 40 mm conical burr set
- 41 settings
- Works for espresso all the way to cold brew
- Powerful 6Nm torque motor
- Anti-static technology (aka mess-free)
- Fantastic warranty
However, I’ll cover the details of bimodal vs unimodal grind distributions below with graphics since the differences in extraction ultimately boil down to these differences in particle size distribution.
What Is the Best Burr Grinder for Beginners?
Putting the nuanced brewing differences aside, I would generally recommend a conical burr grinder like the Baratza Encore because of its affordability. Seasoned coffee aficionados may have control and/or notice the subtle differences in extraction that flat burrs can produce. However, most beginners will not benefit from this extra cost.
Features:
- Baratza's best-selling award-winning entry-level grinder
- 40 grind settings
- 40mm commercial-grade conical burrs
- Fantastic price: quality ratio
- 1-year warranty
Honestly, absolute beginners could probably start with a conical burr hand grinder like the Hario Skerton Pro. It’s highly affordable and you will continue to use it when traveling even after you upgrade to a better electric grinder in the future.
Features:
- Ceramic conical burrs
- Grind adjustment nut (plenty of sizes)
- 60-gram hopper capacity (enough for Chemex)
- Improved update on the original Skerton design
- Heat-proof glass bowl & non-slip cover
Read More: How To Choose The Best Manual Hand Grinder
The Case for Conical Burr Grinders
When it comes to getting a quality coffee grind on a smaller budget, conical burr grinders definitely win, which is why they are frequently seen in entry-level electric models as well as manual grinders. Aside from their cost-effectiveness, conical burr grinders also require less rigorous maintenance—aka you shouldn’t have to deal with calibration and alignment.
The design of conical burrs also means they heat up less during grinding. Many coffee professionals will tell you that this preserves the delicate flavors and aromas of the coffee beans—I can’t say I buy this and have never personally experienced the difference. However, I can understand how less heat would still be of interest to a coffee shop owner who knows the grinder will be used constantly throughout the day.
Bimodal Grind Distribution
Visualizing data in a distribution such as a graph makes it easier to find patterns, and a mode is any relevant peak in the distribution. In such a graph, one peak is unimodal, two is bimodal, and more than two is multimodal. Below is an example of a bimodal grind distribution:
You probably know that proper coffee grinding aims for evenness of particle sizes. That is ideal, however, the reality is that no grinder can truly break brittle coffee beans into exactly the same sizes. You can only hope to create a distribution where a sharp mode occurs at the intended grind size—aka a majority of your coffee ends up at or very close to that size. As you can see from the above chart sampling the particle size of grinds from a conical burr grinder, there are two distinct peaks: one at the intended grind size of 550 microns and another between 50-100 microns, aka the coffee fines.
So, the most likely reason for conical burrs creating a unique flavor is this bimodal grind—the mixture of larger and smaller coffee particles changes the extraction and enhances the body and texture of espresso, making for a rich and complex shot. Conical burrs are also likely better for espresso because a multimodal grind achieves better extraction/water flow in the short duration of pulling a shot.
The Benefits of Flat Burr Grinders
Most often, you will hear coffee professionals and enthusiasts boast about flat burr grinders as having an enhanced grind size consistency, especially for filter coffee methods. While flat burrs are often associated with a higher price tag due to their intricate design, serious coffee lovers will say they are worth it because the grind consistency extracts more sophisticated and subtle flavors in the coffee.
What is it about the flat burr design of two parallel rings that creates a greater consistency? That’s a difficult question to answer, and it scientifically goes beyond the scope of my coffee-geek brain. However, my best guess is that something in the design retains more coffee fines—the smallest particles that break off during grinding—which leads to an unimodal particle distribution.
Unimodal Grind Distribution
As opposed to the two modes pictured above with conical burrs, below is a typical grind size distribution chart for a flat burr grinder in a unimodal grind distribution:
While espresso can benefit for multiple reasons from a bi/multimodal grind distribution, filter coffee methods achieve the most balanced and flavorful cup with an unimodal distribution. As you can see in the chart above, there is one peak (mode) where the majority of the coffee particles fall. Yes, there are still some fines, but it is a negligible percentage of the total coffee volume compared to a multimodal distribution.
Such a grind consistency is ideal for filter coffee, where the prolonged contact time of water and coffee grinds requires this unified grind size for an even extraction. In short, even particle sizes equal an even extraction.
Conical vs Flat Burr Taste Differences
If the scientific differences I described above aren’t your main curiosity, you might still be wondering what the practical differences in taste are between a conical grinder vs a flat one.
Firstly, let’s be clear: both grind designs can produce delicious coffee. The taste difference is more about nuance than better vs worse. On the one hand, the greater grind size consistency of a flat burr design leads to better flavor clarity for pour-over and drip coffee, especially with lighter roasts.
On the other hand, you already know that many coffee pros prefer the bimodal distribution of conical burrs for espresso. And, in terms of the bimodal grind distribution on the coarser grind sizes of filter coffee methods, it creates a more balanced flavor with slightly less clarity of higher acidic notes.
Other Considerations in the Burr Debate
In this final section, I’ll evaluate some other factors beyond grind consistency and price when deciding between flat and conical burr grinders.
Read More: Are Expensive Grinders Really Worth It?
These other factors like maintenance, noise level, heat output, and grind retention are especially relevant if you will be using the grinder in a commercial setting.
Grind Retention
Grind retention refers to how much of the ground coffee sticks inside of the grinder instead of falling out into the bin. Various grinder designs aim to reduce grind retention so you do not waste coffee, a popular method being low-static materials.
However, one upside to higher grind retention is that you will get a more consistent grind size in the bin since the smallest coffee particles/dust (aka coffee fines) will be the primary particles remaining stuck in the grinder. However, as you now know, some will claim these fines benefit the texture of espresso, so maybe this isn’t an upside for espresso lovers.
As I mentioned earlier, the bimodal distribution of a conical burr grinder could ultimately be due to differences in grind retention since gravity pulls fines down more easily in a conical burr design. I would need a scientific lab to solve this one, so I’ll have to leave this hypothesis up in the air for now!
Maintenance
In terms of maintenance, I would have to say conical burrs are more user-friendly. They typically require less frequent cleaning and recalibration, an advantage in both commercial and home environments.
Flat burrs can be remarkably consistent, but you might need to pay closer attention to burr alignment to keep up its precise performance.
Heat and Noise
A grinder’s noise level is an additional concern, especially for those who prefer an early morning brew or live in noise-sensitive environments. The audible difference between flat and conical burr grinders is generally negligible and, much like retention, often comes down to the specific model and design of the grinder in question, rather than the type of burrs it employs.
Heat generation is a further element to contemplate, as excess heat can affect the oils and thus the flavor of the coffee. There is also evidence that colder beans result in a narrower grind size distribution. Conical burrs, due to their design and operation, tend to stay cooler than flat burrs, making them slightly more favorable for high-volume settings where the grinder is continuously in use. This is not only a matter of taste but also of the longevity of the grinder components affected by heat.
Flat Burrs vs Conical Burrs: Final Thoughts on How To Choose
Ultimately, the decision between a flat and conical burr grinder is a nuanced one, influenced by your specific brewing preferences and priorities. If you own an espresso machine at home, I would say to avoid the flat grinders and opt for a conical burr grinder like the Baratza Sette 270 or Virtuoso+— I own a Virtuoso and it performs well for everything from espresso to French Press.
However, if you want a more professional extraction (aka flavor clarity) on brewed coffee with methods like drip, pour-over, and AeroPress (and don’t mind the extra cost), the grind consistency of a flat burr grinder like the Fellow Gen 2 Ode Brew Grinder is an ideal choice.
Get in touch if you have any questions, and I hope this post helps you learn something about coffee grinding and make a more informed purchase!
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FAQs
Are flat or conical burrs better?
The choice between conical or flat burrs depends on which brewing method you want to optimize for. However, flat burrs are generally considered better (and are more expensive) for their superior grind size uniformity.
Why might someone prefer a conical burr grinder over a flat burr grinder?
Someone might prefer a conical burr grinder over a flat burr grinder for its affordability and simpler design, which can be a draw for entry-level coffee enthusiasts and those seeking portability. Additionally, conical burrs are often said to produce a grind that is particularly suited for espresso, due to the bimodal distribution of particles which can add more body to the shot.
Are flat burr grinders better than conical burr grinders for making filter coffee?
Flat burr grinders tend to be better than conical burr grinders for making filter coffee due to their ability to produce more consistent and uniform ground particles. This uniformity in grind size can lead to a more balanced extraction and more flavor clarity when brewing filter coffee, which is prized by many coffee aficionados for highlighting subtle flavors and aromas.
Can the grinder’s design influence retention and noise?
Yes, the grinder’s overall design can significantly influence factors like retention, where grinds may be left behind, and noise level during operation. These aspects are not directly correlated to the type of burr itself but are more related to the manufacturers’ design choices and the quality of materials used in the construction of the grinder.
Which burr design is best for espresso?
While both flat and conical burrs can work for espresso, dialing in espresso shots to the perfect taste is usually easier with a conical burr.
