If your espresso is sour and bitter at the same time, the machine is probably not the problem.
That combination has one main cause: the water found a gap and ran through it, over-extracting the thin part of the bed and barely touching the rest. Fixing the gap is cheaper than fixing the machine.
1. The coffee is not level before you press it
Ground coffee lands in a heap. Press it flat and you have a dense side and a loose side, and the water takes the loose side every time.
Stirring the grounds with anything thin before you press — a needle tool if you have one, a cocktail stick if you do not — breaks the clumps and levels the bed before anything touches it. This is the single change that most often turns a bad shot into a normal one.
2. You are pressing at an angle
Pressing by hand tilts. A tilted bed is the same problem as an uneven one.
Whatever you press with, check the size against your machine first — 51, 53 and 58mm baskets are all common, and a tamper even a millimetre small leaves a rim of loose coffee for the water to escape through. Watching the press from the side rather than from above is what actually catches the tilt.
3. You are guessing the dose
Nobody wants to weigh coffee. But if you do not know how much went in, you cannot repeat the shot that worked, and you will make a good one by accident and never find it again.
Any scale that also runs a timer shows weight and seconds on one screen. Two weeks of that and you will have a number you return to for years.
What we would not buy first
A new machine. A better grinder is a bigger upgrade than a better machine at almost every price point, and levelling the bed is a bigger upgrade than either.
One more small thing: a knock box is not a technique improvement, but banging a portafilter on the bin edge is how the basket gets bent, and a bent basket brings the gap back.
The rest of the coffee kit is in the Kitchen.
More like this
- Four Things That Make Home Coffee Better
- Getting a Small Kitchen Counter Back
- Why Your Knives Go Blunt So Fast
If you are shopping rather than reading: Gifts for coffee people is the pieces on this site for someone who takes coffee seriously.
Common questions
Why does my espresso taste sour and bitter at the same time?
That combination usually means the water found a gap in the coffee bed and ran through it, over-extracting the thin part while barely touching the rest. It is a technique problem, not a machine problem, most of the time.
Will a better machine fix bad espresso?
Probably not first. A better grinder is a bigger upgrade than a better machine at almost every price point, and levelling the coffee bed before you press it is a bigger upgrade than either.
What size tamper do I need?
Check it against your machine's basket first — 51, 53 and 58mm are the common sizes. A tamper even a millimetre too small leaves a rim of loose coffee for the water to escape through.
