Three Essential Elements to Master for Perfecting Espresso Extraction What Are Espresso Coffee Beans?

Introduction

While we rarely drink straight espresso, we can't deny that all the Americanos and various milk coffees we consume are fundamentally based on espresso. Baristas deeply understand that the quality of espresso directly impacts the espresso-based beverages we drink. In this barista training article, we'll share the key elements you need to understand to extract a perfect shot of espresso.

Three Key Elements?

Previous articles from FrontStreet Coffee have analyzed up to six factors that affect espresso flavor. Why have we suddenly narrowed it down to just three? Don't worry – the three key elements mentioned here are those we can control and adjust ourselves: dose, yield, and time.

Don't underestimate these three elements; often, failing to extract the ideal espresso comes down to misunderstanding these factors. Let's start with our extraction goal: we want to extract espresso that is rich and mellow, with abundant and fine crema. Let's use this as our target for extracting espresso.

Dose

Why start with dose? Because this is a relatively fixed-value element. The amount of coffee grounds you use depends on how much coffee the portafilter basket can hold. So how do you know how much coffee your portafilter basket can hold?

First, you can look for the model number engraved on the portafilter basket and find detailed information on the official website. Second, there's an outward-curved ring line inside the portafilter basket. After tamping, if the surface of the coffee puck falls within this ring, it represents a "reasonable capacity." If your tamped coffee puck is above the ring line, you might not even be able to attach the portafilter to the group head. If it's below the ring, it might cause the coffee grounds to tumble during extraction, resulting in unpleasant flavors.

For example, FrontStreet Coffee chooses to use 19 grams of coffee grounds as standard, so each extraction should maintain 19 grams of coffee (accurate to 0.1 grams).

Yield

This refers to how many grams of espresso liquid are extracted. With the dose determined, the relationship with yield creates the brew ratio. Previously, espresso was measured by volume (milliliters or ounces), but since crema volume and weight are not equal, weighing (grams) is now commonly used for greater precision.

Taking FrontStreet Coffee's espresso extraction as an example: 19 grams of coffee grounds extract 38 grams of espresso liquid, giving a brew ratio of 1:2. This ratio is not absolute – it should be determined based on the desired flavor profile. If you extract more coffee liquid, the coffee will taste thinner with more noticeable bitterness. If you extract less coffee liquid, the coffee will be more viscous and concentrated, with a more intense but incomplete flavor profile.

In the past, people also determined the yield by observing color changes in the crema. Espresso initially appears dark brown and concentrated when it first starts flowing, then gradually transitions to golden yellow, and finally to light yellow. Generally, when the crema starts to turn white, it's time to end the extraction.

Time

This is a crucial element in espresso extraction. It introduces a factor called "flow rate." Generally, espresso extraction time falls between 20-30 seconds, with FrontStreet Coffee preferring 25-30 seconds. With dose and yield determined, less time means faster flow rate. If extraction time is below 20 seconds, it may result in under-extraction, causing sourness and astringency, with a relatively thin mouthfeel. If time is longer, it means slower flow rate. If extraction exceeds 30 seconds, it may lead to over-extraction, causing burnt bitterness and a relatively thick mouthfeel.

Similarly, with dose and yield determined, changing extraction time can only be achieved by adjusting the coffee grind size, which brings us to the key adjustment for espresso – grind size. Making the coffee grounds coarser will shorten extraction time, while making them finer will extend extraction time.

Therefore, when adjusting espresso, you're essentially changing these three elements: dose, yield, and time. (Process: Determine dose → Pre-determine yield at 1:2 ratio, set target extraction time range → Taste feedback → Adjust grind size to modify time → Taste when target is reached → If there are still shortcomings, continue by adjusting grind size or changing the brew ratio → Taste and approve → Record)

As for water temperature and pressure, they are equally important for espresso extraction, but it's better to keep them fixed until you've fully mastered the relationship between dose, yield, and time.

Important Notice :

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FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

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