A great coffee is a rich, healthy crema colour. If the coffee is pale or unpleasantly brown, it has been under or over-extracted. The milk should be smooth and silky, with no visible bubbles.

Your coffee should have a light, floral aroma in addition to the usual smell of espresso. You should not smell any burning, as this would mean your milk has been steamed for too long. Also, a strong acidic smell emanating from your coffee may reflect a poor extraction.

In broad terms, your coffee should taste balanced. A great coffee walks the line between acidity and bitterness. Aftertaste is also crucial, as a poorly made coffee can have a strong acidic or bitter aftertaste beyond the initial sip.

Feel, and specifically mouth-feel, is a crucial aspect in enjoying your coffee. Your coffee should be smooth and velvety, with a thickness slightly more than water, but not so thick that it is difficult to drink.