Coffee Brewing Use the largest grind possible on your burr grinder and add the grounds just as the water begins to fill the upper chamber. Leave the pot on the stove for 3.5 minutes and then place on a hot pad. Within 30 seconds the lower pot will cool enough to form a vacuum to pull the brewing coffee into the lower chamber, thereby separating it from the grounds. Experiment with the heating and cooling cycles until the total extraction time is between 4-5 minutes. The best pot available is the old Cona pot or the less expensive, but excellent version from Bodum (both available from Sweet Maria's). Either version will deliver the surprisingly potent aroma that originally made the vacuum pot famous.