Why is the espresso puck wet after extraction? Is the condition of the espresso puck important?

Understanding Espresso Extraction and Coffee Puck Conditions

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Coffee enthusiasts who have extracted espresso at home with espresso machines know that after extraction, there will be a whole coffee puck in the portafilter. This moist coffee puck can indicate whether the espresso extraction was successful. In this article, FrontStreet Coffee will share knowledge about espresso extraction and the condition of espresso pucks.

What Does a Wet Espresso Puck Indicate?

According to FrontStreet Coffee's experience, if the coffee puck is too wet, it could be due to coffee ground too finely, under-extraction, or insufficient machine pressure. Although household semi-automatic espresso machines claim to have 15 bar pressure, they often fall short. Additionally, without steam reflux, the puck tends to be wetter.

However, if the extracted coffee tastes good, there's no need to worry about a wet, watery puck. FrontStreet Coffee believes this isn't a problem at all because brewing espresso requires water. Water permeates the coffee from top to bottom: before dripping onto the coffee grounds, water passes through the boiler, brewing head, and dispersion screen. When you start the pump, water fills the space between coffee grounds and the dispersion screen, then flows into and permeates the coffee grounds.

During this stage, water is everywhere—above, within, and below the coffee grounds. When you turn off the pump, a valve inside the espresso machine opens to release pressure. Water doesn't compress under pressure, so not much water leaks out at this point; it simply remains above and within the coffee grounds. Without pressure, there's no force to push water out of the portafilter or upward through the brewing head. Water becomes "trapped" in the portafilter.

If you quickly remove the portafilter after extraction, you'll notice a puddle of water slowly seeping into the coffee grounds. Within a few seconds, the coffee grounds absorb all the water.

The larger the gap between coffee grounds and the dispersion screen, the more residual water remains. The more residual water, the wetter and more watery your puck will be. In summary, when there's less coffee and more water, the puck becomes wetter. Conversely, when there's more coffee and less water, the puck becomes drier.

How to Make Espresso Drinks

Currently, almost all espresso drinks available on the market are made with different ratios of espresso and milk, such as the Mocha, Latte, and Cappuccino at FrontStreet Coffee. Therefore, the most crucial step in making espresso drinks is producing the espresso itself.

FrontStreet Coffee's Espresso Extraction Parameters:

FrontStreet Coffee uses the Faema E98 espresso machine with the following extraction parameters:

• Pressure: 9 bar ±2
• Temperature: 90.5~96°C
• Time: 20~30 seconds
• Coffee-to-water ratio: 1:1.7~1:2
• Dose: 12g (single shot), 20g (double shot)
• Yield: 20ml (single), 40ml (double)

What is Espresso?

Espresso, also known as espresso, is a beverage made by forcing nearly boiling, high-pressure water through finely ground coffee beans. Espresso is typically thicker than coffee made by other methods, containing higher concentrations of suspended solids and dissolved solids, such as the crema on top (a cream-textured foam). Due to its pressurized brewing process, espresso has intense flavors and very high concentrations of chemical compounds. It's often used as a base for other drinks like lattes, cappuccinos, mochas, and Americanos. However, at FrontStreet Coffee, many coffee enthusiasts also enjoy drinking straight espresso to experience its rich, smooth flavors.

Additionally, some espresso drinks use single shots while others use double shots. What exactly is a double shot? How much espresso is in one cup? FrontStreet Coffee will answer these questions for coffee enthusiasts.

Difference Between Single and Double Shots

According to FrontStreet Coffee, the main difference between single and double shots lies in concentration. At FrontStreet Coffee, a single espresso uses approximately 10 grams of coffee grounds, while a double shot uses approximately 20 grams, but both yield 30 milliliters of espresso. Single shots use single baskets and single-spouted portafilters to extract one single shot. Double shots use bottomless baskets or portafilters to extract double shots in one extraction.

However, FrontStreet Coffee understands that beneath espresso's foam are tiny oil droplets that have dissolved sugars, acids, proteins, and caffeine. Suspended on the foam's surface are bubbles and solid solutions. Therefore, the wear of grinder blades gradually changes with humidity and storage time, requiring daily adjustments to the grind size to ensure stable espresso flavor.

Espresso Coffee-to-Water Ratio

The espresso coffee-to-water ratio is crucial as it directly affects the quality of a coffee drink. The appropriate espresso ratio is key to making good espresso. Therefore, FrontStreet Coffee will briefly discuss the coffee-to-water ratio issue in espresso and how to achieve the proper ratio through adjustments.

First, espresso comes in single and double doses. Traditionally, a single shot uses 8-9 grams of coffee grounds to extract 25-35 milliliters of espresso in 30 seconds. The traditional single-shot ratio is 1:1, which has been used for the longest time. Single shots have strong, rich flavors that many find difficult to drink straight. An important step in dosing is weighing—placing the portafilter on a scale, zeroing it, and weighing approximately 9g of coffee grounds. Extracting 25-35g of espresso liquid between 25-35 seconds is considered an appropriate ratio. Single shots are commonly used for cappuccinos, with equal proportions of milk, espresso, and foam, traditionally in a 1:1:1 ratio depending on cup size.

Double shots naturally double the amount on the basis of single shots. Using 18-20g of coffee grounds in the same 25-35 seconds to extract 55-65g of espresso liquid is considered an appropriate ratio, also at 1:1. The same procedure involves weighing and zeroing. Double shots are the main amount used for making lattes and Americanos. In terms of taste, they're richer and heavier than single shots because adding milk and water dilutes the concentration in exchange for a fragrant, smooth mouthfeel. Single shots would make the coffee taste insufficient, so double shots should be determined based on cup capacity.

How to determine how much coffee to use? The above describes traditional single and double espresso doses. Coffee baskets come in different specifications, with single baskets holding up to 14g. This should be adjusted according to the reference line in the basket. There's an indented powder line in the basket that serves as the reference line for the prescribed dose. The filled amount can be adjusted according to this reference line—exceeding it means too much coffee, or it could be due to overly coarse grinding causing larger gaps between particles.

Using weighing methods can accurately achieve reasonable coffee-to-water ratios. Espresso grind should be flour-like in fineness, typically adjusted between 1-1.5 on the espresso grinder's smallest settings. The main adjustments are based on dose and extraction time, which is the accurate method.

What Coffee Beans to Use for Espresso

Additionally, using different espresso beans to make espresso will present different coffee flavors. For example, the espresso beans used at FrontStreet Coffee are a blend of Honduras Sherry coffee and Yirgacheffe Natural Red Cherry coffee, which highlights rich chocolate, caramel, and slightly intoxicating flavors when mixed with milk.

Espresso machines have a distinctive characteristic of amplifying the original flavors of coffee beans. Light roast coffee beans naturally have more prominent acidity. If extracted with an espresso machine, this acidity becomes even more pronounced, making them unsuitable for making espresso.

Next, FrontStreet Coffee will recommend the following four espresso beans for everyone to choose from.

FrontStreet Coffee Sunflower Warmth Blend

Flavor: Obvious fruit acidity, light berry aroma, wine notes, rich chocolate flavor, obvious sweet aftertaste.

Formula: Honduras Sherry : Yirgacheffe Red Cherry = 6:4

For this blend, FrontStreet Coffee uses Yirgacheffe Natural Red Cherry and Honduras Sherry. FrontStreet Coffee's design concept for this blend is that it can be used for both espresso and pour-over. When used for espresso, it emits obvious fermented wine aromas. When tasted, citrus and berry acidity immediately emerge, with whiskey-like aroma and a black chocolate aftertaste.

FrontStreet Coffee Premium Blend

Flavor: Gentle, slightly acidic, light sweetness, nutty aftertaste, overall not too stimulating, balanced, medium crema.

Formula: Colombia : Brazil = 3:7

For this blend, FrontStreet Coffee uses Brazil and Colombia. It tastes like light roasted grass fragrance, fresh aroma with slight bitterness, sweet and smooth, with a comfortable aftertaste. This is because coffee beans from Colombia's Huila region have pleasant acidity, aromatic flavor, moderate acidity, and rich sweetness that's very intriguing. Coffee beans from Brazil's Cerrado region have comfortable bittersweet flavors and are extremely smooth when tasted. Together, they create a truly wonderful combination.

FrontStreet Coffee Commercial Blend

Flavor: Caramel sweetness, nutty and cocoa notes, black chocolate flavor, balanced sweet and sour, slightly bitter, persistent aftertaste.

Formula: Colombia : Brazil : Robusta = 3:6:1

For this blend, FrontStreet Coffee uses Brazilian and Colombian coffee beans with 10% Robusta coffee beans. It has a classic taste. FrontStreet Coffee believes this blend has rich crema and texture with caramel sweetness, plus nutty and cocoa notes, black chocolate flavor, balanced sweet and sour, slightly bitter, with a persistent aftertaste. This commercial blend, like FrontStreet Coffee's Premium Blend, uses Colombian and Brazilian coffee beans, but the addition of Robusta provides rich crema, making the coffee texture more mellow.

FrontStreet Coffee Basic Blend

Flavor: Gentle fruit acidity, caramel sweetness, nutty and black chocolate flavors, smooth and viscous, but relatively mild in taste.

Formula: Yunnan : Brazil = 3:7

For this blend, FrontStreet Coffee uses Brazil and Yunnan. FrontStreet Coffee believes it tastes of gentle fruit acidity and caramel sweetness, plus nutty and black chocolate flavors, smooth and viscous, but relatively mild in taste. This is because Yunnan's natural conditions are very similar to Colombia's—high altitude, large temperature differences between day and night, with mellow flavor characteristics, moderate acidity, rich and mellow taste, uniform particles, high oil content, and fruity notes. Its quality and texture are similar to Colombian coffee, though slightly milder. Coffee beans from Brazil's Cerrado region have comfortable bittersweet flavors and are extremely smooth when tasted. Therefore, the combination of these two coffee beans also has excellent flavor, and this basic blend coffee bean offers excellent value, suitable for espresso beginners and small coffee shops.

The above is the knowledge about espresso compiled by FrontStreet Coffee, hoping to help coffee enthusiasts better understand espresso-related knowledge.

For more specialty coffee beans, please add FrontStreet Coffee's private WeChat account: kaixinguoguo0925

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473