Tamping is an important part of the espresso making process, but what size tamper should you use? Not all tampers can work in any basket or any machine and it’s important to make sure you’re using the precise size you need. Paying close attention to your tamper size and your tamping technique to get the even pressure, better flow, and more consistent shot you want.
Understanding espresso tampers
Espresso tampers are an essential espresso-making tool. Tamping is the part of the espresso process where you form the puck, which is what you need to extract the perfect cup. The more compact and properly formed you’re able to make the puck, the better the extraction and the more flavorful your espresso.
As a quick review, here’s how to use an espresso tamper:
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Put your coffee grounds into the basket.
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Break up any clumps with a clump crusher.
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Grab the tamper the way you would a doorknob with your thumb pointing down.
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Hold the tamper above the basket with your forearm straight and your elbow at a 90 degree angle.
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Press down firmly, being careful not to angle your arm.
Types of espresso tampers
There are two main types of tampers. The most common type is the flat-based tamper. It features a smooth, flat base that helps ensure even pressure distribution. Convex tampers, however, have a slightly rounded base to eliminate the need for leveling and push the grounds toward the center of the basket.
While you can technically use either type of tamper with any portafilter or machine, the best way to tell which to use is to look at the bottom of your basket simply. Some baskets on the market actually have a slightly rounded base.
That’s where a convex tamper would come in handy. If the bottom of your basket is flat, stick with the flat-bottomed tamper. This is the best way to get the even distribution you’re looking for.
Why do tampers affect espresso quality?
Using a cheap or poor-quality tamper can definitely affect your espresso, but the technique is even more important. That’s because tamping creates resistance, which is what you need to form the puck tightly. It pushes the air out of the espresso, making it easier to avoid channeling, which is when water rushes down pathways in the espresso grounds instead of evenly saturating them. Channeling is your enemy, because it leads to weak and inconsistent shots.
Choosing a tamper of high-quality stainless steel like Pesado’s tampers helps you avoid wobbling, weak pressure, or uneven compression. Every little bit you can do to get the perfection you’re after adds up to help get you there.
How to determine what size tamper you need
What size tamper for 58mm portafilter is necessary vs. a 51mm portafilter or other, more unique size can be an annoying thing to figure out. That’s because the tamper needs to fit snugly inside the portafilter to avoid uneven extraction and channeling — two things that can lead to a really poor-tasting cup of coffee. But if the tamper is too snug, you’ll struggle to get it into the basket, which can also lead to poor, messy tamping.
Because espresso portafilters aren’t all made to a single standard size, you’ll need to know exactly what size you’re working with. The most common sizes are 58 mm, 54 mm, and 51 mm, but they can run even smaller. To be absolutely sure, you should measure it.
How to measure your portafilter to find the right tamper size
If you want to be precise, here’s how you’ll want to determine what size tamper to get.
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Using a precise ruler with 1/32 inch markings, measure your portafilter basket’s diameter.
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Convert the measurement to millimeters (feel free to use an online calculator here).
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This is the measure of your portafilter. To find your tamper size, subtract 0.75 mm from the portafilter diameter.
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If your measurement ends in a decimal, round to the nearest whole number: that’s your tamper size!
Things can get a little tricky if your basket tapers, because then you’ll need to measure the narrowest part to ensure the tamper doesn’t get stuck. Ultimately, this might mean your proper tamper size is about a millimeter smaller than your portafilter basket.
Common portafilter sizes & tampers that fit
Since some portafilter sizes are pretty standard, let’s examine one of the most common sizes and what size tamper you’ll need there. Then, you’ll be ready to start shopping for the perfect tamper!
What size tamper fits a standard 58mm portafilter?
So all the tips on precise measurements aside, if you have a 58 mm portafilter, then the most likely size tamper for you will be a 58 mm tamper. That might sound a little confusing! After all, didn’t we just discuss that there should be a small amount of room between the side of the tamper and the sides of your basket? That’s true! But because we’re dealing with tenths of a millimeter, the most likely truth is that your basket, if you were to measure it yourself, might be slightly larger than 58 mm, like 58.2 or 58.4 mm. That little extra wiggle room would be why a 58 mm tamper could work for you!
But given the small amount of flexibility here and the precise measurements we’re talking about, that’s why it’s always best to measure everything yourself to be certain. You never know how much a portafilter could vary from one machine to the next, even if they’re from the same brand. Small variations are inevitable!
A 58 mm portafilter is often up to 58.7 mm in diameter, so choosing a 58, 58.3, or 58.5 mm tamper is perfectly acceptable. Many espresso enthusiasts and experienced baristas use a 58.5mm tamper for a snug fit that keeps coffee from sticking to the portafilter's walls.
What size tamper should you use for non-standard portafilters?
If you have a non-standard portafilter, simply follow the same measurement tips above. With a more unusual size, accuracy is even more important, so it makes the most sense to measure yourself for optimal results.
Where to buy a high-quality espresso tamper
Now that you know exactly what size tamper you need, you can grab the perfect one for you from Pesado’s collection. In fact, they offer an array of 58.5 millimeter tampers made from quality stainless steel.
Designed to last a lifetime, you can grab the right tamper for your machine and know it’ll stand the test of time — especially if you’re making espresso every day. Choose a precision-fit Pesado tamper today.
