What is the pressure on a Rok espresso maker?
HOW MUCH EXTRACTION PRESSURE DOES THIS MACHINE GIVE? We’ve designed the Presso Smartshot to perfectly balance the extraction pressure so you get a tasty coffee, cup after cup. Extraction pressures will vary depending on the amount and fineness of coffee grinds. Expect between 6 and 10 bar. THE PERFECT PRESSURE LEVEL It’s a rare example of almost-total agreement across the coffee world. Nine bars of pressure, which is nine times the weight of air at sea level, is the gold standard for extracting consistently great espresso in a 25- to 30-second time frame.The role of pressure in espresso extraction incorrect pressure can lead to under- or over-extracted espresso, which affects the quality and taste of the final product. At pressures lower than 9 bar (taking this value as a notional limit), the coffee becomesmore watery and the crema diminishes.In the past, espresso was measured by volume, where a single shot of espresso was roughly 30 milliliters and a double shot was roughly twice this volume, or 60 milliliters.Multiply 18 x 2 this gives us 36. Therefore, we will pull 36g of liquid espresso in 25-35 seconds. For example, we should aim to extract 36g of liquid espresso from the 18g of ground coffee in 30 seconds, giving us our target ratio of 1:2.