Category: Espresso

If your coffee tastes sour, it’s under-extracted: the water passed through too quickly and didn’t pull out the sugars and oils that balance the acidity. If it tastes bitter and burnt, it’s over-extracted: the water was in contact too long and dragged out the bitter compounds. The good news is that both problems are fixed with the same four controls: grind, dose, temperature and time. This guide teaches you to diagnose and correct each case.

Why coffee tastes sour (under-extraction)

Acidity is the first note extracted. If the water passes through too fast, you only pull the acids and miss the sweetness that balances them. Typical causes:

• Grind too coarse: water rushes through the coffee without time to extract.
• Low dose: there’s little coffee and the water passes without resistance.
• Cold water: below 90 °C extraction slows down and comes up short.
• Short extraction time: the coffee finishes in under 20 seconds.

Why coffee tastes bitter (over-extraction)

Bitterness is the last note extracted. If the water passes slowly or stays too long, it drags out the bitter compounds from the end of the extraction. Typical causes:

• Grind too fine: water barely passes and over-extracts what it touches.
• High dose: too much coffee for the water available.
• Water too hot: above 96 °C it burns and bitters.
• Long extraction time: over 35 seconds, or too long a steep with immersion methods.
• Over-roasted or old coffee: dark roasts and stale coffee bitter more easily.

The quick diagnosis table

• Sour + finishes in under 20 s → grind finer.
• Sour + lukewarm water → raise the temperature (90-96 °C).
• Bitter + finishes in over 35 s → grind coarser.
• Bitter + boiling water → lower the temperature.
• Bitter + very dark roast → reduce the dose or change the roast.
• Sour and bitter at once → uneven extraction: check the leveling of the coffee bed and the tamp.

How to adjust one variable at a time

The most common mistake is changing two things at once. If you grind finer and also raise the temperature, you won’t know what worked. The method:

1. Set the base recipe: 18 g of coffee, 36 g of liquid, 25-30 seconds, 90-96 °C.
2. Brew one cup and note the flavor and the time.
3. Change one variable only (usually the grind, which has the most effect).
4. Repeat until the time is right: if the time works, the flavor almost always follows.

Adjustments by method

Espresso: the grind is the main control. Sour → finer; bitter → coarser. If the problem persists, check temperature and dose.

Filter coffee (V60, Chemex): besides the grind, control the pour. Sour → grind finer or pour slower; bitter → grind coarser or lower the water temperature (aim for 92-94 °C).

French press and AeroPress: here the steep time is the main control. Sour → lengthen the steep; bitter → shorten it. With the AeroPress, a fine grind with a slow press also helps.

When the problem isn’t extraction

• Old coffee: coffee loses sweetness and gains bitterness over the weeks. Check the roast date, not the best-before date.
• Hard or chlorinated water: bad water flattens flavor. Try filtered water.
• Dirty machine: stale oils in the group and portafilter bitter any coffee. Clean the group regularly.
• Very dark roast: if the roast is the problem, no grind adjustment fully fixes it. Try a medium roast.

FAQ

Why is my espresso sour even when I grind finer?

The temperature may be low, or the dose too small. Also check that the portafilter is properly filled and level: an uneven bed gives uneven extraction.

Does bitter coffee mean more caffeine?

No. Bitterness comes from over-extraction, not caffeine. An over-extracted coffee can even have less caffeine than a well-extracted one.

What water temperature do I use for each method?

Espresso, 90-96 °C. Filter, 92-96 °C (lower for dark roasts). Immersion, 85-95 °C depending on the method. No thermometer? Wait 30-60 seconds after boiling.

How long should an espresso take?

25-30 seconds from the first drop, for 36 g of liquid with 18 g of coffee. Less time, sour; more, bitter.

Can I fix sour coffee with milk or sugar?

You can mask it, but not fix it: the problem is in the extraction and it will repeat in every cup. Adjust the grind and you’ll get good coffee without needing to cover it.

Sour and bitter coffee aren’t flaws of the brand: they’re messages from your extraction. Learn to read them, change one variable at a time, and within a few cups you’ll be pulling balanced coffee — sweet, not burnt. The timer and the grinder are your best allies.

A perfect espresso isn’t luck: it’s an equation of four variables — grind, dose, pressure and time — that you can learn to control. If your coffee tastes sour or bitter, the machine isn’t the problem: one of those variables is off. Here’s the method to find the sweet spot.

The four pillars of espresso

• Grind: coffee should be ground right before extraction. A fine grind (like sugar) slows the water and extracts more; a coarse one lets water through fast and extracts less. A burr grinder is essential: blade grinders can’t produce consistency.
• Dose: the amount of coffee in the portafilter. The standard is 18 grams for a double, but what matters is the ratio with the liquid that comes out.
• Pressure: 9 stable bars at the pump. You don’t need more; you need it to not fluctuate.
• Temperature: between 90 and 96 °C in the water that touches the coffee. Too cold, the espresso turns sour; too hot, bitter and burnt.

The base recipe

Start with this base and adjust from there:

1. 18 g of coffee, ground fine, in the portafilter.
2. Level and tamp: the coffee bed must be flat and even. One firm tap with the tamper and done — no brute force needed.
3. Extract 36 g of liquid (1:2 ratio) in 25-30 seconds from the first drop.

If the time is right, the flavor usually follows. If not, adjust the grind — not the dose or the pressure.

How to read your extraction

• Under 20 seconds, watery and sour coffee: grind too coarse. The water passed through quickly and extracted too little. Grind finer.
• Over 35 seconds, bitter and burnt coffee: grind too fine or dose too high. The water was in contact too long. Grind coarser.
• Channeling from one side of the portafilter: the coffee bed isn’t level or the tamper was crooked. Distribute better before tamping.
• Pale, bubbly crema: old or over-roasted coffee. Try fresh coffee.

The most common mistakes

• Pre-ground coffee: it loses aroma within days. Buy beans and grind at the moment.
• Changing two variables at once: adjust one thing per cup; if you change grind and dose together, you won’t know what worked.
• Tamping with brute force: tamp pressure matters less than leveling. One firm, even tap is enough.
• Ignoring the timer: the clock is your best tool. Without a reference time, you’re guessing.
• Rushing the warm-up: the machine needs 15-20 minutes to stabilize temperature, not 2.

When to adjust the recipe

• More acidic or lightly roasted coffee: try extracting a bit longer (1:2.5 ratio) to soften the acidity.
• Dark roast coffee: extract a little less (1:1.8) to avoid bitterness.
• Humid days or very fresh coffee: the grind can behave differently. Adjust fine or coarse based on extraction time.

FAQ

Do I need an expensive machine to make good espresso at home?

No. With a basic semi-automatic, a good burr grinder and fresh coffee you get a respectable espresso. Technique matters more than the machine.

How much coffee for an espresso?

For a double, 18 g of coffee and 36 g of liquid. For a single, half — though most modern portafilters are designed for doubles.

Why is my espresso sour?

Because it’s under-extracted: coarse grind, low dose or cold water. Grind finer and make sure the machine is hot.

Why is it bitter?

Over-extraction: grind too fine, too much time or water too hot. Grind coarser and reduce the time.

Does espresso have more caffeine than filter coffee?

By volume, yes; by cup served, no. A single espresso (30 ml) has less caffeine than a cup of filter coffee (200 ml).

Want to go further? Learn the difference between filter coffee and espresso to choose your method well, or discover how to pick the best espresso machine to get started.

Both are coffee, but they barely resemble each other beyond that. Espresso is a concentrated 30 ml drink made in 25-30 seconds with pressurized water; filter coffee is a full carafe made in 3-6 minutes with water that falls by gravity. The difference isn’t quality: it’s intent. This guide explains how the result changes and which to choose at each moment.

Extraction: pressure vs gravity

• Espresso: 9 bars of pressure push water at 90-96 °C through very finely ground coffee in 25-30 seconds. It extracts oils and suspended solids that paper filters retain.
• Filter coffee: water falls by gravity through coarser ground coffee over 3-6 minutes. It extracts more slowly and more completely, but without the pressure that emulsifies the oils.

The grind

• Espresso: fine grind, almost like powdered sugar. The contact surface is enormous and extraction is extremely fast.
• Filter: medium grind, like coarse salt. Water takes longer to pass, so the coffee needs less surface area.

The ratio and the result

• Espresso: 1 part coffee to 2 parts water (18 g → 36 g of drink). Result: 30 ml concentrated, with crema (the golden foam of emulsified oils), dense body and intense flavor.
• Filter: 1 part coffee to 15-17 parts water (60 g per liter). Result: 200-300 ml per cup, lighter, no crema, more flavor clarity and less bitterness.

Caffeine: the espresso myth

An espresso has 60-80 mg of caffeine in 30 ml; a filter cup, 90-140 mg in 240 ml. By volume, espresso wins by a mile; by cup, filter carries more. If you want a quick boost, espresso; if you want sustained caffeine, filter.

Flavor and body

• Espresso: intense, with dense body and notes perceived in concentration. The base of cappuccinos, lattes and Americanos.
• Filter: cleaner and more balanced, with perceptible acidity and clearer notes. It’s the format professional tasters use to evaluate a coffee.

Which to choose for each moment

• Busy morning: espresso or Americano. Quick to make if you have a machine.
• Relaxed morning or remote work: filter. A carafe lasts all morning and is gentler on the stomach.
• After a meal: short espresso, digestive and no volume.
• Work afternoon: filter in a big cup, sustained caffeine without spikes.
• With milk: espresso, always. A cappuccino or latte is made with an espresso base, not filter coffee.

FAQ

Does espresso have more caffeine than filter coffee?

Per milliliter, yes; per cup, no. An espresso (30 ml) has 60-80 mg; a filter cup (240 ml), 90-140 mg.

Which is healthier?

Neither is bad in moderation. Paper-filtered coffee retains diterpenes (compounds that raise LDL cholesterol); espresso, not passing through paper, keeps them. For high consumption, paper-filtered coffee is the most studied option.

Can I make espresso without a machine?

You can get close with a Moka pot or an AeroPress, but it’s not real espresso: the 9 bars of pressure are missing and the crema doesn’t form the same way.

Why does filter coffee taste less bitter?

Because of the gentler extraction and the paper filter, which retains part of the oils and solids that pass into the cup with espresso.

Is an Americano espresso with water?

Yes: espresso + hot water. It’s the way to drink a “long” coffee with espresso’s profile.

There’s no winner: espresso is intensity and filter is clarity. Keep both at home (a drip machine and a Moka or espresso machine) and choose by the moment.