To extract the perfect espresso shot, there are really only two key adjustments we need to ensure are correct on the espresso grinder. Those adjustments are the dose volume and the grind adjustment. The dose volume is the amount of coffee that is dispersed in the portafilter. The grind adjustment refers to how fine or how coarse the machine grinds the espresso beans.
The perfect dose volume contains 14 -16 grams of ground espresso beans. To measure the dose volume you will need a barista scale and a portafilter. Begin by turning on the barista scale and ensuring it is set to measure weight in grams. Then place a clean dry protafilter on the scale to set the base weight. While the portafilter is on the scale, press the “on/off” button on the scale to reset the scale to zero based on the weight of the portafilter. Now fill the portafilter with a full dose of espresso from the grinder. Being careful not to spill any of the espresso grinds, place the full portafilter on the barista scale. The scale will now tell you the grams of espresso grinds that are in the portafilter.
To adjust the dose volume:
- Ensure the espresso grinder is set to Barista Mode.
- If it is set to barista mode, the screen will say “barista” and will look like the image below.
- If it is not set to barista mode, alert your manager and ensure the grinder is set back to the proper function.
- From this point, use the minus and the plus buttons to decrease or increase the volume respectively. You should typically increase or decrease the volume by increments of one tenth of a second.
- The dose buttons are simply buttons set to different dose volumes to help you quickly increase or decrease the dose volumes during busy times. You can select any of these three buttons then use the minus or plus buttons shown above to get to your desired dose volume.
The espresso grinder determines dose volume based on time (measured in seconds). We measure the dose volume based on weight (measured in grams). Adjusting the grind of the espresso bean will effect the dose volume. If you grind the espresso beans to be more fine (crushing the beans smaller) your volume (in grams) will decrease because it takes more time (in seconds) to grind the espresso beans. The opposite is true of adjusting the grind to be coarser.
As you adjust your grind to be finer, you will also need to adjust your dose volume by increasing the amount of time the machine spends grinding the beans and thus keeping your weight constant at 14 to 18 grams of espresso beans. The opposite is true for adjusting your grind coarser.
The grind adjustment refers to how coarse or how fine you grind the espresso beans. We measure the grind of the espresso based on the amount of time it takes for the water in the espresso machine to run through the beans when we pull a shot. This is referred to as your extraction time. The perfect extraction time is 24 seconds.
We use the rocks vs sand analogy to help understand the espresso grind concept. Imagine you have two cups; one filled with rocks and one filled with sand. If you pour water over the top of both cups, what will happen? The water will run very quickly through the cup filled with rocks and will run very slowly through the cup filled with sand. The same is true with your espresso grind. The coarser your grind (the larger the grind) the faster water will run through it. Like the rocks. The finer your grind (the smaller grind) the slower it will run through. Like the sand. So we adjust the grind on the espresso grinder more fine or more coarse to increase or decrease shot time respectively.
To adjust your grind:
- Turn the grind adjustment knob (shown below) clockwise to make your grind finer, or
- Turn the grind adjustment knob counter clockwise to make our grind courser.
Adjusting your grind will effect the dose volume. You will need to adjust your grind and dose volume together to obtain the perfect shot. Your dose volume will also increase or decrease extraction time. The more espresso grind the water has to get through (higher dose volume), the longer your extraction time will be. The opposite is true of a lower dose volume. Try to maintain a 14 gram dose volume at all times. Slight adjustments to the dose volume can correct your extraction time without adjusting your grind.