Do you want to know the differences between conical vs flat burrs?
In short words, conical burrs produce slightly inconsistent coffee grouds but they are quiet and very convenient. On the other hand, flat coffee grinders produce extremely precise coffee grounds but they are noisy and create a lot of heat in their grinding process.
The Coffee Arsenal is a trusted source of coffee gear guides and this is one of them.
In this guide, you will find the definition of conical burrs and flat burrs, and the most important differences between them.
Conical vs Flat Burrs: Definitions
Before going deep into each difference between conical vs flat burrs it’s essential to know the basic concepts and their unique pros and cons.
The conical burrs are composed of two parts, the outer part, and the inner part. The outer piece is a block that has small burrs on its inner walls.
The inner part is simply a cone with bigger burrs on its outside walls.
The coffee grinding process takes place when the inner piece rotates and its small burrs make contact with the burrs of the outer piece, causing the coffee beans to be ground and ejected through the lower space between the two pieces.
The coffee grinding process in this type of grinder is highly influenced by gravity and its motor is not as powerful as other types of grinders. They operate at 500 RPM on average.
- Does not get very hot which doesn’t affect the quality of the beans
- High control over the grind size
- Easy to clean
- Does not retain a lot of coffee grounds
- Produce subtly inconsistent ground coffee
Flat burrs are basically two grindstones made of steel or ceramic that are placed in parallel with each other.
The grindstone (the base) is closed and has burrs on its walls, while the upper grindstone has a hole through which the coffee beans enter and also has burrs on its walls.
This type of burrs grinds the coffee beans when these two grindstones come into contact with each other, and finally, the coffee beans come out through the lateral holes that exist between the two grindstones.
As I said before, there are two types of flat burrs, ceramic flat burrs, and steel flat burrs.
Ceramic flat burrs are generally sharper than steel flat burrs, can produce a consistent grind size without losing sharpness for a long time, and absorb less heat.
However, these ceramic flat burrs can break easily if a hard object (like a small rock) hits them.
On the other hand, steel flat burrs are much stronger than ceramic burrs but they lose their sharpness faster and absorb more heat.
They operate at 10,000 RPM to 20,000 RPM on average which makes them very fast.
- Produce consistent ground coffee
- They do get very hot, which affects the quality of the grounds they produce
- Produce a lot of noise
- Hard to clean
- Tend to retain coffee
Conical vs Flat Burrs: Differences
Now that you understand the basic concepts, let’s move on to the differences between conical vs flat burrs.
In short words, flat burrs produce more consistent grounds, while conical burrs produce more inconsistent coffee grounds. However, you gotta know that these discrepancies are very subtle and it is really hard to note them at a glance.
Flat burrs produce smaller particles, smaller particles extract faster and larger particles extract slower, which means that conicals will hit their sweet stop at a lower overall extraction than flats because of the presence of more fine particles.
This difference is the result of the unique way they are built.
Conical burrs work better at shorter ratios:
On the other hand, flat burrs work better at longer ratios:
Also, there are grinders that are specifically designed for espresso.
Around 300 to 450 microns (A micron is a metric unit of measurement where one micron is equivalent to one one-thousandth of a millimeter) is the ideal burr size range for a perfect espresso shot.
One of the most subtle differences that not many people take into account is the retention and contamination of coffee grounds.
After using your coffee grinder, there is a possibility that coffee grounds may remain between the parts of the grinder after each extraction.
This causes the new particles to become contaminated by making contact with the old particles over time.
This phenomenon is more common in flat burr coffee grinders due to the fact that this type of grinder uses the mechanical power of its motor to grind.
On the other hand, this is not so common in conical burr coffee grinders because this type of grinder works with a motor and also with the power of gravity. This second factor decreases the probability of the attachment of coffee particles to the grinder parts.
In short, there is a higher risk of coffee bean contamination in flat grinders than in conical grinders. However, you should always clean your grinder after a day of work to avoid a bad flavor in the next shots
Professional baristas find conical burrs more forgiving than flat burrs. They say that conical burrs are easier to dial in and require fewer adjustments.
On the other hand, several people say that conical burrs are easier to clean because of their design. Flat burr grinders have more mechanical parts that require constant maintenance.
As I said before, conical burrs produce ground coffee with certain microscopic inconsistencies.
These inconsistencies can affect the flavor and body of certain types of beverages.
For example, to produce a perfect shot of espresso we need extremely fine coffee beans with as few inconsistencies as possible.
This is because to make this type of beverage we need the water to pass as fast as possible through the coffee beans using a certain pressure and if there are imperfections in the ground coffee the flavor may not be consistent and may even be a bit more bitter.
In short words, espresso shots produced using a flat burr grinder are usually a bit less bitter than using conical burr grinders because of the consistency of the grounds.
By knowing all of this, wouldn’t be crazy to say that flat burr grinders are better for espresso and siphon brewing methods (These two methods require very fine coffee grounds) and conical burrs would be better for drip coffee, pour-over, and french press. (These three methods work fine with coarse and medium size coffee grounds).
Disclaimer: This is a very controversial topic, there are a lot of people that say that there are not any differences between them and there are people that say that exists a difference in flavor between them.
This information is based on an in-depth research but you should always do your own testing and find out what works better for your current personal situation and preferences.
In general, high-quality coffee grinders can grind 1,000 to 1,500 pounds of coffee beans before falling apart. This can vary a lot depending on the type of coffee you are grinding usually, as well as its roast degree.
Also, you should keep in mind the amount of work you are putting in your burrs and the maintenance that you give to it, a coffee grinder with good daily maintenance will last two or three times more than a coffee grinder poorly cared for.
Last but not least, high-quality coffee grinders tend to last much longer than cheap coffee grinders due to the quality of the materials from which they are built.
You can get a high-end model for over $100, below that you will get a poor-quality coffee grinder.
Keep in mind that you will need to spend some money from time to time because of the maintenance of these machines, you will need to buy special tools and products to clean them.
Also, you should keep in mind that your coffee grinder could get broken and you will need to spend some money to fix it.
The design of conical burr coffee grinders allows them to run at a lower RPM than flat burr coffee grinders, and with a lower RPM, they produce a lot less noise.
This is a characteristic that you should keep in mind, for example, if you live with your family you won’t want to wake up everybody just to make yourself a cup of coffee, however, if you have a coffee shop you won’t care about this noise.
Heat is an extremely important factor that you should keep in mind when buying any kind of coffee grinder.
As flat burr grinders run with a higher RPM they tend to “burn” the coffee beans while they are grinding them. Obviously, this will change the body and flavor of the shots you prepare using these burned grounds.
To avoid this you can buy a low-speed coffee grinder and you can grind your beans strategically by making short pauses in the grinding process.
On the other hand, conical burr grinders don’t have this tendency because they have a lower RPM, logically, less friction and speed concludes in less heat.
Now you understand the basic concepts and the main differences between these two burrs.
As always, you should keep your needs in mind before buying any kind of coffee equipment.
Both of them are great and they have their unique pros and cons.
Do you want a super-precise coffee grinder and you don’t mind making a lot of noise? Go for the flat burrs.
Do you want a convenient and flexible coffee grinder and you don’t mind losing a bit of consistency? Go for the conical burrs.
F.A.Q – Conical vs Flat Burrs
I have made this section to give answers to the most common questions I get asked about conical vs flat burrs.
What Are the Advantages of Conical Burrs Over Flat Burrs?
The advantages of conical burrs over flat burrs are: less heat, less noise, they are easier to clean, and they have less probability of retaining coffee grounds.
Are Flat Burrs Better Than Conical Burrs?
They are not better, each one has its own unique pros and cons and you should make your decision based on your needs.
For example, flat burrs offer an extremely precise size consistency but they produce a lot of noise, heat and they are more difficult to clean.
On the other hand, conical burrs produce a slightly less consistent size of ground coffee but are quieter, easier to clean and generate less heat.
Does a Coffee Grinder Make a Difference?
Absolutely yes! Using a coffee grinder can save you a lot of time and effort when grinding coffee beans. They are great for people that don’t have much time to grind their coffee beans or for coffee shops with a high demand for coffee drinks.
Why Are Burr Grinders So Expensive?
Burr coffee grinders are usually expensive because they are sophisticated machines created to save tons of time and effort. However, you don’t have to spend hundreds of dollars to buy a good-quality coffee grinder. You can buy a decent one for a bit more than $100.