Flat vs Conical Burrs: Which Is Better?

Speed, heat, grind uniformity, cost, flavor—flat burrs and conical burrs each come with their own strengths and weaknesses. Picking your coffee grinder’s burr type is one of the most consequential choices you’ll make for your coffee experience. That’s true for both business owners and home baristas.

At Mahlkönig, we’ve been manufacturing the world’s most trusted coffee grinders and burrs for over 100 years. We want to help you make the right choice for your context. Let’s break down each burr type so you can pick the right one for your goals and needs.

Flat Burr Grinders Explained: Unimodal and Consistent

Flat burr grinders use two parallel steel discs with cutting edges that face each other horizontally. Picture two flat donuts lying on top of each other.

Coffee beans fall between these discs and get cut into uniform particles as they work their way outward from the center. This perpendicular grinding action creates exceptionally consistent particle distribution—called unimodal—which basically means all the grounds are virtually the same size with an almost imperceptible margin of difference that minimizes the fines and boulders that can plague extraction consistency.

This means any coffee made with any brew method will taste better, and be easier to brew consistently. But the difference is most clearly felt in espresso, where tiny inconsistencies in coffee grounds can create extraction problems.

Flat burrs produce more predictable espresso shot timing, reduced channeling in espresso, and ultimately better tasting espresso. This is why dedicated espresso grinders almost universally feature flat burrs.

Mahlkönig's E65W GbS and E80W GbS espresso grinder models exemplify advanced flat burr technology, featuring our 65mm and 80mm precision steel burrs respectively. These grinders combine flat burr uniformity with smart Grind-by-Weight and Grind-by-Sync technology, making them a great fit for commercial settings where espresso consistency and speed are critical, like espresso bars and cafes. 

Flat burrs aren’t without their trade-offs though: slightly higher heat generation during extended grinding sessions and more static buildup, though modern designs like Mahlkönig's cooling systems and clump-reducing flappers mitigate these concerns.

Flat Burrs At A Glance

• Precision: Unimodal, very precise
• Consistency: High
• Speed: Fast
• Heat: Medium
• Cleaning: Easy
• Cost: Medium

Conical Burr Grinders Explained: Bimodal and Cool

Conical burr grinders use a cone-shaped inner burr that sits inside a ring-shaped outer burr. Coffee beans fall down through the gap between these burrs, getting crushed into smaller and smaller pieces as they spiral their way down with the help of gravity.

This design has a fundamental flaw: it creates bimodal particle distribution. This means that the resulting coffee grounds are not all identical in size, but are a mixture of two sets of different sizes. Think mixing table salt and flaky kosher salt—look closely enough, and you’ll see two sizes of grounds blended together. If you are using a high-end conical burr grinder, it may be very difficult to visually see these two different particle sizes, but the physicals of conical burrs mean this bimodal distribution is always present.

Bimodal particle distribution can cause disruption and inconsistency for espresso-making, since even tiny, almost imperceptible changes in particle size can impact the shot quality. The fine particles extract faster than the larger ones, leading to simultaneously over-extracted and under-extracted flavors in the same shot. This is why serious espresso operations have largely moved away from conical burr designs.

Conical burrs do have their advantages though. They tend to run cooler and quieter due to the lower RPM requirements, which makes them well-suited for bulk grinding into bags or making batch brew filter coffee in cafes. They also tend to retain fewer grounds since gravity helps clear grounds from the burr chamber.

Conical burr technology works well for budget-conscious cafes, lower-volume operations, or businesses primarily focused on drip coffee rather than espresso.

Conical Burrs At A Glance

• Precision: Bimodal, less precise
• Consistency: Medium
• Speed: Slow
• Heat: Low
• Cleaning: Easy
• Cost: Low

Head-to-Head Comparison: Flat vs Conical Burrs

The Bottom Line: Flat burrs excel where precision and consistency matter most—especially for espresso. Conical burrs offer simplicity and affordability but compromise on the uniformity that serious coffee operations require. 

For commercial espresso and other quality-forward coffee service settings, the superior particle consistency of flat burrs typically justifies the higher investment. Conical burrs remain a decent option for lower-volume operations or businesses where espresso isn't the primary focus, or for roasters who need to grind large volumes of beans into bags.

How to Choose the Right Grinder for Your Setup

Your burr choice should align with your primary brewing method, volume demands, and quality expectations. Here's how to decide:

For espresso-focused operations

Flat burr grinders offer the precision and consistency required for quality espresso. The unimodal particle distribution ensures predictable extraction timing and superior flavor clarity. If you're pulling more than 100 shots daily, invest in a commercial-grade flat burr espresso grinder with stepless or electronic grind settings for fine-tuning capabilities.

For multi-method brewing

If espresso represents a small portion of your coffee service, conical burrs offer versatility across brewing methods. The bimodal distribution that hurts espresso will make far less of an impact in drip coffee, french press, and pour overs.

**Most coffee shops use both a flat burr grinder for espresso and another flat or conical grinder for drip coffee and pour overs.

Volume considerations

High-throughput operations benefit from flat burrs' speed and consistency. Low-volume cafes might find conical burrs adequate, especially if budget constraints are significant.

Budget vs. ROI

While flat burr systems require higher upfront investment, they typically deliver better long-term value through reduced waste, faster workflow, and superior consistency. An adjustable burr coffee grinder with precise grind settings pays dividends in operational efficiency and customer satisfaction.

The Verdict on Burr Shapes: What We Really Think

We’ve been creating commercial coffee grinders for a full century at Mahlkönig, and flat burrs have been at the center of nearly every advancement in precision, consistency, and flavor clarity. In most situations, flat burrs simply grind better coffee.

When you're trying to extract the most nuanced flavors from coffee, particle uniformity matters more than almost anything else. Conical burrs create a scattered mix of sizes that extract at different rates. Flat burrs create uniform particles that extract together, as a team.

That said, flat burrs traditionally run hotter and create more static. So we created innovative systems in our grinders to outsmart those problems: active cooling systems, quieter motors, reduced-static designs, larger diameter burrs that require fewer rotations to grind coffee, and the world’s most precise burr manufacturing to minimize friction.

Conical burrs have their place for budget-conscious operations and simple setups, or in high-volume roasteries that grind coffee into bags by the thousands. But when coffee quality and consistency drive your business and you want every opportunity to make your coffee taste its best—flat burrs deliver.

Want to see how our world-leading flat burrs can improve your business? Connect with your local Mahlkönig distributor to discuss your specific requirements and see our innovations in action. Your coffee deserves equipment that matches your ambition.