What is the 30 second rule for espresso?
The 30-second extraction rule suggests that a well-balanced espresso shot should take approximately 25-30 seconds to extract when using 18-20 grams of ground coffee and yielding about 30-40 milliliters of espresso. If your coffee machine is taking longer than usual to brew, or the espresso isn’t extracting a shot the way it should, these may be signs that your espresso machine needs a deep clean.