There are 3 main factors that will change your Extraction Time:
- Water Volume — This is the amount of water that is coming from your espresso machine
- Dose Volume — This is the amount of coffee beans coming out of your espresso grinder
- Grind Adjustment — This is how course or how fine the espresso grinder is grinding the espresso beans
We will check all 3 of these factors when we first set up the espresso bar in the morning and anytime you take over the espresso machine station on your shift.
The first factor we will check is the Water Volume. To test this, we will use a single leg protafilter and a shot glass to measure the amount of water coming out of the espresso machine. The perfect amount of water that should be coming out of the machine is 3.5 oz. If you are getting more or less than 3.5 oz out of the machine, See the section on adjusting your espresso machine.
It is also important to note that each group head on the espresso machine and each dose button within that group head may be set to have different Water Volume. You will want to check each group head and dose button individually to ensure they are all consistent.
Water Volume does not change very often. The espresso machine is typically very consistent and you should only have to adjust the water volume on rare occasions. But since it is a major factor in the shot, we always want to check to ensure our machine is still on point.
The next factor we will check is the Dose Volume. To test this, we will need our portafilter and our barista scale. Place the empty portafilter on the barista scale, then hit the on/off button to reset the weight to zero. Then fill the portafilter with beans from the coffee grinder. Next place the full portafilter on the barista scale to check the weight. The perfect dose will have 14-16 grams of Espresso beans. If you do not have 14-16 grams, see the section on adjusting your espresso grinder.
There are 3 different dose volume buttons on the espresso grinder. Each of these are typically set to slightly different grind times so you can quickly increase or decrease your dose volume. Try each dose volume button to see if one will produce the correct amount of espresso beans. We will adjust the dose volume multiple times throughout the day. It is very normal for us to slightly increase or decrease the dose volume to ensure our we are using the correct amount of espresso.
The last factor we will check is our grind adjustment. As long as our Water Volume and Dose Volume are correct, the grind adjustment will be the only factor that changes our extraction time. So we test the grind adjustment based on the extraction time. If the grind is too course, the water will pass through the coffee too fast (meaning your espresso machine will stop pouring, but there is still time on your timer). When this happens, your shot will taste sour. If the coffee is too fine, the water will pass through the coffee too slowly (meaning your espresso machine is still pouring but your timer has gone past 24 seconds). When this happens, your shot will taste burnt. See the section on adjusting the espresso grinder for more information on how to adjust your espresso grind.
Like the dose volume, we will adjust the espresso grind multiple times throughout the day. This is where the art of making coffee comes into effect. We will play with slight variations on each of these factors to ensure we are getting the perfect shot.