What to do if espresso coffee extraction is too fast

If when you are extracting espresso, the water is passing through the ground coffee too quickly, you will not achieve good crema and the coffee will not pick as much flavor from the beans. There are essentially two things you can adjust: the fineness of the grind, or the pressure used for tamping. Either of these steps will create greater resistance to the water passing through. Tamping should ideally be around 30lbs of pressure (practice using some scales to find out how much weight you need to put behind your tamper). The grind for espresso is fairly fine, but you should use a grinder that has multiple grind settings so that you can adjust it till you find the right grind. The extraction should take about 20 or so seconds. If it's happening faster than 20 seconds and you aren't getting good crema production, then vary either or both of these things.
Hint: Did you know that once you open your coffee beans, unless you are storing them in a vacuum container, they will quickly start to dry. As they dry, you should adjust the setting on your grinder to be more fine as the beans dry - that way you will still be able to produce crema. The other thing is to use your beans up quickly!