Coffee Compass

Adjust your coffee extraction: identify under-extraction and over-extraction issues and get correction suggestions.

How to use the coffee extraction compass

The extraction compass helps you diagnose what is off in your cup and shows which way to adjust your brew to reach sensory balance. Instead of changing everything at once, you find the likely cause and the most effective fix.

The core idea is the difference between under-extraction and over-extraction. Under-extracted coffee tends to taste sour, salty and thin; over-extracted coffee turns bitter, dry and harsh. The compass reads the flavor you describe and points to whether extraction is lacking or excessive.

From that diagnosis, the tool suggests adjustments to grind size, coffee-to-water ratio, time and temperature, one at a time, so you can isolate each variable and improve the recipe with method.

Frequently asked questions

What are under-extraction and over-extraction in coffee?

Under-extraction is when too little soluble material has been drawn from the coffee, leaving the cup sour, salty and light-bodied. Over-extraction is the opposite: too much extraction, bringing bitterness, astringency and dryness. The sweet spot sits in the balance between them.

My coffee tastes sour, what should I do?

A sour taste usually points to under-extraction. Try grinding finer, raising the water temperature slightly, or extending the contact time. Change one variable at a time and taste again.

My coffee tastes bitter, how do I fix it?

Bitterness and dryness generally point to over-extraction. Grind coarser, lower the temperature, or shorten the extraction time. Adjust only one variable and reassess the cup.

Does the compass work for espresso and pour-over?

Yes. The principles of under- and over-extraction apply to espresso, V60, French press, Aeropress and other methods. The intensity of the fix changes, but the direction of the adjustment is the same.

Do I need a scale and timer to use it?

It helps a lot. Measuring your coffee-to-water ratio and time makes adjustments repeatable. Without them you can still improve the cup, but reproducing the result is harder.