Posted on June 02 2017
By Sarah Bottoms
Throughout the coffee industry, there are countless preferences and methods when it comes to preparing and extracting espresso. It can be overwhelming when you’re trying to learn or teach staff and have all kinds of instruction from different sources contradicting one another.
We’ve researched and experimented with many methods ourselves, but a tried and true set of guidelines comes from Scott Rao and his collection of revolutionary books on espresso and other aspects of coffee preparation. “The Professional Barista’s Handbook: An Expert’s Guide to Preparing Espresso, Coffee, and Tea” is a tool that we put a lot of stock in and have found to be an effective guide for us at the roastery and with our customers.
The barista’s role in serving espresso is laid out nice and clear by Rao and I'd love to go through these goals with you so that we can highlight the importance of them when it comes to serving your customers!
1.“Create a dose of consistent mass every shot.”
Be aware of how much coffee you are dosing into the portafilter. In a perfect world, espresso grinders should be calibrated first thing and then periodically throughout the day. This can be done simply by weighing the coffee in conjunction with the amount of time coffee is dispersed. A good target for a double shot would be between 18-20 grams of coffee for a final product of 2 oz. of espresso. Coffee is super volatile, so even when you’ve calibrated your grinder to dose a certain amount – the dose and grind can change naturally over time depending on the environment. It's tricky, but as a barista, it’s something to be aware of.
2. “Choose the grind setting that will provide the desired flow resistance.”
Grind setting is just as important as dose weight! They correlate with one another and have to be in sync to pull a good shot of espresso. “Desired flow resistance” refers to water pulling through the coffee bed at a desired rate. If you imagine water trickling through the fine particles of compact sand versus that same water traveling through coarse pebbles, you can envision the difference between a fine grind and a coarse grind when it comes to pulling espresso. Don't be fooled...water is lazy! It will travel the most direct and available way, so a fine and compact coffee bed is the key. Espresso shouldn't pull too fast or too slow.
3. “Distribute the dose evenly to provide uniform resistance to the water.”
An uneven coffee bed can produce channeling to which our lazy water will beeline to, resulting in under-extraction as a result of unused coffee. Distribution begins as soon as you put the portafilter under the grinder. Be sure to allow the coffee to evenly fill the portafilter. Next, “tamp with enough pressure to eliminate void spaces within the coffee bed and to seal the surface of the bed.” That being said, don’t feel like you need to lay all your weight into the tamper! It’s unnecessary and can potentially be harmful to your wrist. I always tell baristas to hold the tamper like a door knob, elbow up, and then to evenly apply just enough pressure to push any air out of the coffee bed. It's always good to clean up the sides so that any excess coffee is brushed off. I always flush the screen by running the machine to preheat and rinse any coffee residue. Finally, you’re ready to insert the portafilter into the espresso machine and pull the perfect shot!
4. “Ensure the brewing water is of the desired temperature”.
This is something that is more for your barista to be aware of rather than something they can physically control. If the temperature gauge reads anything unusual (low or high), it should be addressed by your tech. Espresso should be pulled between 185-204 degrees Fahrenheit, and we suggest closer to the 200 degree range. Lower temperatures out of this range will produce sour and under-extracted espresso while higher temperatures out of this range will produce bitter and acrid flavors. Neither taste good! Some espresso machines have temperature gauges (PID control), and for those that don’t, it’s as simple as running a thermometer under the water if you or your baristas sense something is off.
If you and your baristas follow these guidelines we guarantee it will result in an improved quality shot of espresso! Well, I suppose we can't guarantee...but with these good habits I can assure you that your customers will keep coming back for the knowledge and skill set of your baristas, as well as a damn good shot of espresso.