Flat vs. Convex Tampers Compared  

As an espresso enthusiast, I want to know which tamper is best for espresso. That led me to write this guide.

I’ll talk about what each tamper type is, their pros and cons, and how they’ll impact espresso taste and extraction. Afterward, I’ll talk about how to find the best espresso tamper.

Here in an overview:

Let’s dive in.

Key Takeaways

• Convex tampers help prevent espresso channeling.
• Flat tampers often result in better-tasting espresso.
• Flat tampers are much easier to find.
• Espresso made with flat tampers are prone to leaks.

How Tamper Type Affects Taste & Extraction

A test I found suggests that flat tampers have a better extraction rate than convex tampers since the coffee grounds are evenly packed [1]. This test showed that flat tampers had 0.20 (0.33%) more Total Dissolvable Solids (TDS) than the coffee produced with a convex tamper.

Drinks made with flat tampers tend to have a creamier, smoother taste than those using convex tampers.

Flat vs. Convex Tampers

Let’s see how tamper shape will affect your espresso’s extraction and taste.

Flat Tampers

These sections will explain what flat tampers are, advantages and disadvantages to using them, and some of the best ones available.

What are Flat Tampers?

A flat tamper is a type of tamper that has a flat base. It evenly distributes coffee grounds and creates a consistent puck. Flat tampers are the most common type of tamper and are a good choice for beginners and experienced baristas alike.

Pros & Cons of Flat Tampers

Pros of flat tampers include:

• More flavorful coffee: More extraction results in great-tasting coffee.
• Better for beginners: No learning curve to developing technique.
• Widely available: Flat tampers are easy to find.

Cons of using this type of tamper include:

• Prone to leaks: Edges of packed grounds are prone to water leaking in.
• May not be as aesthetically pleasing: Some people prefer the look of other types of tampers.
• Prone to espresso channeling: Water may channel between basket edge & packed grounds.

Some evidence suggests that flat tampers have better extraction than convex tampers due to the resulting espresso puck’s shape [3]. They’re not an ideal solution to preventing donut extractions, espresso channeling, and spritzing.

You’ll have less aesthetically-pleasing espresso extraction, but you’ll have a better-tasting drink.

Best Flat Tampers

Here’s a comparison of the best flat tampers for espresso:

Convex Tampers

This section will explain what convex tampers are, pros and cons to using them, and some of the best ones available.

What are Convex Tampers?

A convex tamper is a type of tamper that has a slightly rounded base. This shape creates a more consistent puck and to prevent espresso channeling.

Channeling is a problem that can occur when water flows through the coffee grounds unevenly, resulting in a weak or uneven espresso shot.

Pros & Cons of Convex Tampers

Advantages of using convex tampers include:

• Helps prevent side-channeling: Prevents water from seeping down sides of baskets.
• Faster extraction (sometimes): A thinner center can lead to slightly faster espresso extraction.
• Could reduce espresso spritzing: Espresso flows more evenly through grounds in the thinner center of the puck.

Disadvantages of using convex tampers include:

• Can create a weaker espresso shot if not used properly. If a convex tamper is not used properly, it can create a weaker espresso shot.
  • This is because the rounded base can create a seal that is too tight, which can prevent water from flowing through the coffee grounds evenly.
• More difficult to use: The rounded base of a convex tamper can make it more difficult to apply even pressure to the coffee grounds.
• More difficult to clean: The rounded base of a convex tamper can make it more difficult to clean.
  • This is because water can get trapped in the curves of the tamper, which can create a breeding ground for bacteria.

The rounded base of a convex tamper creates a better seal between the coffee grounds and the portafilter basket. This seal helps to prevent water from flowing around the edges of the puck and channeling through the coffee grounds.

It’s more challenging to distribute pressure with convex tampers evenly. Because of the rounded shape, which could unbalance the pressure created around your espresso puck.

And because it’s more difficult to apply pressure, you have more of a learning curve. Once you master a technique, you should have a more evenly extracted espresso.

Best Convex Tampers

Here are some of the best convex tampers available:

What Is a Tamper?

You would use a tamper for an espresso machine to pack the coffee grounds into the portafilter. The purpose of a tamper is to distribute the coffee grounds and create a consistent puck.

A well-tamped puck will help to ensure that the espresso has an even extraction and produces a good crema.

Many types of tampers are available, made from various materials. Some popular materials for tampers include stainless steel, aluminum, and wood. Tampers come in multiple sizes; choosing the right size for your portafilter is essential.

To use a tamper, place it on top of the coffee grounds in the portafilter and press down. The amount of pressure you use will depend on the type of tamper you have and your personal preference. Some people prefer to use a light tamp, while others prefer to use a heavier tamp.

Many baristas will recommend applying 20 to 30 pounds of pressure when tamping [2].

Other Factors That Affect Espresso Taste

Tamper shape is a small part of what will alter your espresso’s taste. You’ll also need to consider the following:

Here are further descriptions for each section in the table:

• Headspace: Too much headspace can cause channeling.
  • Too little headspace can restrict the flow of water & result in a weak extraction.
• Basket shape: A round basket will create a more even extraction.
  • A conical basket can create a more concentrated extraction.
• Screen curve: A flat screen can create a more even extraction.
  • A curved screen can create a more concentrated extraction.
• Grinder: A finer grind will create a more concentrated extraction.
  • A coarser grind will create a more dilute extraction.
• Grind consistency: A consistent grind will create a more even extraction.
  • An inconsistent grind can create a more uneven extraction.
• Ramp: A slow ramp will create a more even extraction.
  • A fast ramp can create a more uneven extraction.
• Hand: Too much pressure can create a more concentrated extraction.
  • Too little pressure can create a more dilute extraction.
• Brew pressure: The ideal brew pressure is 9 bars.

Factors to Consider When Choosing a Tamper

There are a few factors to consider when choosing a tamper for your espresso machine:

• Size: Should be the same size as your portafilter basket. This will ensure that the coffee grounds are evenly distributed & that the puck is the right thickness.
• Material: Tampers are typically made from stainless steel, aluminum, or wood.
  • Stainless steel is the most durable material, but it can also be the most expensive.
  • Aluminum is less expensive than stainless steel, but it is not as durable.
  • Wood is the least expensive material, but it can warp over time.
• Weight: Will affect the amount of pressure you apply when tamping.
  • A heavier tamper will require more force to use, while a lighter tamper is easier to use.
• Handle: Should be comfortable to grip & should provide a good amount of control.
• Price: Can range in price from around $10 to $100 or more.

Some tampers also give you the ability to adjust the weight you apply. These will cost more, though.

Read reviews, consult with experts, and watch videos on people using the tamper you want. From there, decide which is the best option.

Conclusion

Flat tampers work better for beginners and can provide more extraction. They’re not ideal for preventing espresso channeling. Convex ones work better in that area.

Experiment with both tamper types to see which works better for your home. Afterward, if you’re searching for a new tamper, consider one of our recommendations.