Making espresso at home can be incredibly rewarding, but it’s easy to fall into common pitfalls that affect flavour, consistency, and overall enjoyment. Even small errors in grind size, tamping, dosing, or machine maintenance can drastically alter your espresso. Here’s a practical guide to the main mistakes home baristas make and how to fix them.
1. Incorrect Grind Size
The Problem:
The grind size is arguably the single most important factor in espresso. Too coarse, and water will flow too quickly, resulting in weak, under-extracted espresso. Too fine, and water will struggle to pass through, producing a bitter, over-extracted shot.
Why It Happens:
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Using pre-ground coffee instead of freshly ground beans.
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Not adjusting the grind when changing coffee types.
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Inconsistent grinder performance.
How to Fix It:
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Invest in a quality burr grinder — consistency is key.
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Start with a medium-fine grind, then adjust slightly finer or coarser depending on shot timing.
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Aim for an extraction time of around 25–30 seconds for a standard 30ml espresso shot.
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Keep a small notebook or record of settings for each coffee to fine-tune your routine.
2. Uneven or Inconsistent Tamping
The Problem:
Tamping compresses the coffee evenly in the portafilter. Uneven tamping leads to “channeling,” where water finds weak spots in the coffee puck, causing under-extraction in some areas and over-extraction in others.
Why It Happens:
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Pressing too lightly or inconsistently.
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Tilting the portafilter while tamping.
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Not distributing coffee evenly before tamping.
How to Fix It:
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Use a distribution tool or simply tap the portafilter lightly to level the grounds before tamping.
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Apply firm, even pressure (about 30 pounds / 13–14kg) with a flat tamper.
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Keep the tamper perpendicular to the puck.
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Avoid twisting the tamper after pressing — just a straight downward press.
3. Incorrect Dose
The Problem:
Too little coffee produces a weak, watery shot. Too much coffee can block water flow, creating bitter, over-extracted espresso.
Why It Happens:
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Not weighing coffee.
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Using a scoop inconsistently.
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Not considering grind size adjustments.
How to Fix It:
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Invest in a small digital scale for consistent dosing.
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Standard dosing for most home machines is around 18–20g for a double shot, but adjust for your specific machine and bean.
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Adjust dose in combination with grind size to achieve proper extraction.
4. Poor Water Quality
The Problem:
Hard water can cause scale buildup and affect taste, while very soft or distilled water can produce flat-tasting espresso.
Why It Happens:
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Using tap water without checking mineral content.
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Not descaling the machine regularly.
How to Fix It:
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Use filtered or bottled water with balanced mineral content (around 70–150 ppm total dissolved solids).
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Descale your machine according to manufacturer instructions to maintain flow and temperature consistency.
5. Incorrect Extraction Time
The Problem:
Too short or too long extraction affects flavour: short = sour, weak; long = bitter, harsh.
Why It Happens:
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Inconsistent tamping or grind size.
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Wrong dose.
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Not timing shots properly.
How to Fix It:
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Use a timer to monitor shot duration.
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Adjust grind and dose so your espresso flows for around 25–30 seconds.
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Observe flow — it should resemble warm honey, smooth and continuous.
6. Not Preheating Your Equipment
The Problem:
Cold portafilters or cups can lower extraction temperature, leading to underwhelming espresso.
Why It Happens:
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Skipping warm-up routine.
How to Fix It:
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Run water through the machine and portafilter before brewing.
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Preheat cups with hot water or by running a blank shot.
7. Neglecting Machine Maintenance
The Problem:
Build-up of coffee oils, residues, or limescale affects taste and machine longevity.
Why It Happens:
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Skipping backflush and descaling routines.
How to Fix It:
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Backflush your machine regularly (once a week for home machines).
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Clean portafilters, baskets, and steam wands after each use.
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Follow descaling schedule recommended by the manufacturer.
| Common Espresso Mistake | Why It Happens | How to Fix It |
|---|---|---|
| Incorrect Grind Size | Too coarse → under-extracted; too fine → over-extracted | Use a quality burr grinder. Adjust grind for 25–30s extraction. Keep notes for each coffee. |
| Uneven Tamping | Causes channeling → uneven extraction | Level the grounds, press evenly with ~30 lbs pressure, keep tamper straight. Avoid twisting. |
| Wrong Dose | Too little → weak espresso; too much → bitter/blocked | Weigh coffee (18–20g typical double shot). Adjust with grind for proper flow. |
| Poor Water Quality | Hard water → scale; soft water → flat taste | Use filtered water (70–150 ppm TDS). Descale machine regularly. |
| Incorrect Extraction Time | Short → sour; long → bitter | Aim for 25–30s shot. Adjust grind/dose to control flow. |
| Cold Equipment | Lowers extraction temperature | Preheat portafilter, run blank shot, warm cups. |
| Neglected Maintenance | Coffee oils, residue, limescale affect taste | Clean portafilter, baskets, and wands after each use. Backflush weekly and descale per instructions. |
Summary: Small Adjustments, Big Difference
Perfect espresso is about consistency. By paying attention to grind size, tamping, dose, water quality, extraction time, and equipment maintenance, you can dramatically improve your shots. Start with one adjustment at a time, observe the results, and refine your technique.
Remember: even minor improvements in each step add up to a noticeably better espresso experience.
