How to Dial In Coffee Grind Size, Dose, and Tamping for Espresso

If you’ve ever pulled a shot that tastes sour, bitter, or just weak, chances are something in your espresso setup—grind size, dose, or tamping—is off. These three factors control how water flows through coffee, which dictates flavor, body, and extraction yield. But here’s the catch: there’s no universal setting. What works for one roaster’s beans on one grinder may not work elsewhere. So how do you get it right?

The short answer? Grind size is your primary control, but it’s relative to your specific machine, beans, dose, and tamp. There’s no magic number on the grinder dial—it’s a starting point. Once you find the right feel for the grind, use your fingers to assess texture. Dose depends on your basket size and grind. And tamping? That’s where your touch saves the shot when everything else shifts.

What Actually Determines Grind Size?

Many baristas ask: “What number should I set my grinder to?” The truth is, grind size settings—those numbers or letters on your grinder dial—are not universal. They vary by brand, model, and even between individual units of the same model. A ‘3’ on one grinder might be a ‘6’ on another, even if they’re from the same manufacturer.

Think of the grind setting as a directional guide: lower numbers usually mean finer, higher means coarser. But those numbers only start to make sense once you’ve found the extraction sweet spot for your specific setup. From that point, you can use the scale to make minor adjustments. Just remember: the setting is only useful if you don’t change beans, dose, or tamp pressure.

Here’s a pro tip: once you’ve dialed in a grind you like, get familiar with how it feels. Rub a small amount of ground coffee between your fingers. Is it gritty? Powdery? Over time, you’ll learn to recognise the right texture. If you switch grinders or something feels off, trust your fingers more than the number. If it feels clearly coarser, adjust finer—and vice versa. This tactile feedback is faster than trial and error and helps when switching machines.

How Much Coffee Should You Dose?

You might hear a barista say, “I use 18 grams,” but that number only works in their specific context. Dose depends on several linked factors: the coffee you’re using, the grind size, your basket size, and how hard you tamp. Change one, and the others may need to follow.

For example, a 18g dose might work perfectly in a double basket with a medium-fine grind, but if you change to a finer grind, you might need to adjust dose or risk channeling. Likewise, switching to a coarser grind could call for more coffee or a firmer tamp to slow extraction. Your dose isn’t just a number—it’s part of a balanced equation.

The bottom line? Always consider your dose as part of the whole setup. There’s no universal “correct” dose. It’s about what works with your specific beans, grind size, basket, and tamp pressure to produce a balanced shot.

Why Is Tamping Pressure So Variable?

Of all the variables in espresso preparation, tamping pressure is the most inconsistent—because it’s done by hand. Unlike grind size or dose, there’s no objective measurement for how hard you tamp. New baristas often think in terms of ‘light’ or ‘hard,’ but experienced baristas rely on feel.

Even seasoned professionals can tamp differently from day to day depending on fatigue, mood, or even arm strength. That variability might seem like a problem, but it’s also one of your best tools for fine-tuning. While grind size, dose, and coffee batch can be affected by environmental changes (like humidity or bean density), tamping is something you can adjust shot-by-shot to stabilise extraction.

If your shots are running too fast or tasting under-extracted, a slightly firmer tamp can slow flow and improve contact time. If they’re bitter or over-extracted, easing up on the tamp might help. Tamping is your real-time correction tool, especially when other variables shift unexpectedly.

Does the Coffee Bean Itself Change Everything?

Absolutely. Different coffee beans—whether by origin, variety, or roast level—affect how they grind, how densely they pack, and how they extract. For example, a high-density Ethiopian Yirgacheffe will grind differently from a low-density Brazilian Natural. The roast level matters too: lighter roasts are harder and denser, while darker roasts are softer and more brittle.

This means the grind size, dose, and tamping that worked for one bean might fall apart with another, even on the same grinder. It’s not that one bean is better or worse—it’s that each has its own physical properties. That’s why some cafés dedicate specific grinders to certain beans, ensuring more consistent results.

So if your shots suddenly taste off after switching beans, don’t assume your technique is wrong. Your grind, dose, or tamp might simply need to adapt to the new coffee’s density and grind behavior.

Frequently Asked Questions

What grind size should I start with for espresso?

There’s no universal starting number, because grinder settings vary by brand and model. Instead, start with a setting in the middle of your grinder’s range (often around 3 to 5), then adjust based on taste. Aim for a grind that produces a 25–30 second extraction with balanced flavour. Use your fingers to assess the texture—it should feel finer than table salt but not powdery.

How much coffee should I use for a double shot?

Most double baskets call for around 18–20 grams of coffee, but the ideal dose depends on the basket size, grind size, and your tamper pressure. Start with the dose recommended for your basket, then adjust based on flow rate and taste. The goal is a well-packed puck that extracts evenly without channeling.

How hard should I tamp espresso grounds?

Aim for a consistent, firm tamp—about 30 pounds of pressure, though there’s no need to measure exactly. The key is evenness and repeatability. Tamp hard enough to create a level, compact puck, but let your feel guide you. If shots run too fast, tamp slightly firmer. If they’re bitter, ease up.

Why does my espresso taste different when I use a different grinder?

Different grinders produce different grind shapes and consistencies, even at the same nominal setting. Blade grinders are inconsistent; flat and conical burr grinders offer more uniformity. Even two identical grinders can perform differently due to wear or calibration. Always dial in grind size anew when switching machines.

Do I need to adjust my grind if I change coffee beans?

Yes. Different beans—by origin, roast level, or density—grind differently and extract differently. A light roast Ethiopian will need a different grind size than a dark roast Brazilian. When changing beans, start with your usual setting but be ready to adjust based on extraction time and flavour.

Can tamping too hard ruin my shot?

Yes. Over-tamping can restrict water flow too much, leading to over-extraction, bitterness, and long shot times. It can also increase channeling risk if the puck becomes uneven. Tamp firmly and evenly, but not excessively. Consistency matters more than raw pressure.

Recommended FrontStreet Coffee Beans for Dialling In

For practising grind, dose, and tamping, try FrontStreet Coffee’s Ethiopia Humbera – a bright, juicy Ethiopian with floral and citrus notes that highlights extraction clarity. Also great is their Brazil Queen Manor, a nutty and chocolatey washed Brazilian that’s forgiving and great for dialling in dose and balance. Finally, their Yirgacheffe offers high acidity and floral complexity, ideal for fine-tuning grind fineness. Freshly roasted within 5 days · Orders placed before 17:00 ship the same day · Next-day delivery across most of Guangdong Province.