Espresso Extraction Explained

Extraction describes how much soluble matter moves from the ground coffee into the cup. Getting it right decides sweetness, acidity and bitterness – and it is the core of every good espresso.

Under-extraction (too little)

If the shot runs too fast or too little is dissolved, it tastes sour, salty and thin. Causes: grind too coarse, too little coffee or too little time. Fix: grind finer or increase the dose.

Over-extraction (too much)

If too much is dissolved, bitterness and a dry, astringent feel dominate. Causes: grind too fine, too much time or water too hot. Fix: grind coarser or reduce the time.

The sweet spot

Balanced means: sweet, clear acidity, pleasant body, no dry finish. You find it by changing one variable per attempt and tasting – exactly what the dial-in assistant helps with.

How to read it

• Sour & thin → under-extracted → finer / more time.
• Bitter & dry → over-extracted → coarser / less time.
• Sweet & round → sweet spot → save the recipe.