Let's first take a look at how espresso is properly extracted...

• Start with freshly roasted coffee blended specifically for espresso
• Proper grind setting is essential
• 7-14 grams of ground coffee dosed into the espresso handle (group handle)
• A 30-35lb tamp (packed even and flat into the handle)
• Water that is 8-10 bars (approx. 125lbs of pressure, and 192-198 degrees (fahrenheit) forced through the coffee)
• A 1-1.50oz extracted shot of espresso that takes 18-24 seconds

This guideline has been set by the specialty coffee association, a non-profit organization for the further development of the coffee industry.

The importance of proper tamping techniques:

It is important not to over-extract or under-extract the finely ground espresso. This can only be acheived by not too much or not too little compaction of the ground espresso. Water flows easier through loosely packed coffee and flows slower through tightly packed coffee.

Another problem is that if the pack is un-even, the water will find the path of least-resistance and over-extract the low points and under-extract the high points.

The ultimate goal is to achieve a more consistent 30-35lb tamp that's even and flat. This will produce a perfect espresso every time, thus ensuring returning customer satisfaction.