Espresso Brew Ratio: 1:1.9 Extraction Time: 26-30 seconds. This means that for every gram of ground coffee dosed into the porta-filter there is 1.9 grams of coffee extracted. If using and dosing with an 18g porta-filter you can extract approximately 34-grams of liquid (coffee). Still stuck? Check out this link to learn more about brew ratios - click here.