To fix a slow, over-extracted espresso shot (taking longer than 30 seconds), primarily adjust your grinder to a coarser setting to reduce resistance. Other effective fixes include reducing the coffee dose, applying lighter tamping pressure, or ensuring even distribution to prevent water channeling.
Pouring Too Slow: Over-Extraction Risks
This means you're pulling more than just the pleasant soluble compounds from the coffee — you're also extracting tannins and bitter compounds. Symptoms include: Harsh bitterness. Dry, astringent mouthfeel.
To make this happen, look to your grinder. We'll manipulate the grind size to change how long water flows through the coffee bed. Think of coarse coffee like stones and fine coffee like sand. The water will make its way through the rocks much more quicker.
My coffee is running too fast or too slow
The "espresso 30-second rule" is a widely used guideline suggesting an ideal espresso shot should extract in 25-30 seconds for a balanced flavor, acting as a starting point for dialing in your grind size and brew ratio, though taste remains the ultimate judge, as factors like roast level and machine type can alter this. Timing usually starts when the pump activates, but some prefer from the first drip; shots under 20 seconds are often sour (under-extracted), while over 35 seconds can be bitter (over-extracted).
The "espresso 2:1 rule" refers to the common guideline of a 2:1 brew ratio, meaning you extract two parts liquid espresso for every one part of dry coffee grounds by weight, typically aiming for 30-35 seconds extraction time for a balanced shot. For example, 18 grams of grounds yields about 36 grams of espresso, and it's a flexible starting point, not a strict law, allowing adjustments for taste by changing the ratio (e.g., 1:2 for more intense, 1:3 for a longer lungo).
The 80/20 rule (Pareto Principle) in coffee means 80% of flavor comes from 20% of the variables, emphasizing that a few key factors—fresh, quality beans; proper grind; and good water—yield the best results, rather than obsessing over every tiny detail. It suggests focusing your effort on core elements like sourcing great beans and grinding fresh for significant flavor improvement (the 80%), while the remaining 20% of brewing nuances (like water temperature precision) offer diminishing returns.
For espresso, the key is a consistent 9 bars of pressure, not the 15 or 20 bars advertised on machines; higher pump pressure (20 bar) provides a helpful buffer for beginners, compensating for inconsistencies in grind or tamping, while a good 15-bar machine with an Over-Pressure Valve (OPV) also achieves the ideal 9 bars, with stability and control being more important than the maximum number. A 20-bar machine offers more power, potentially better for uneven grinds and quicker recovery, but a quality 15-bar machine with proper regulation can brew excellent espresso too, making consistent 9-bar pressure the real goal.
To us, the wrong basket size and under or overstuffing your basket are the number one cause of faulty flow rates when brewing espresso at home. While the rest of the suggested issues will be in order from grinding to brewing, we put this first as it is one of the biggest culprits.
EXTRACTION TIMES
A 30ml single espresso should extract between 27 – 35 seconds. Using a Double 18-21g basket: A 30ml single espresso should extract between 15 - 20 seconds. A 60ml double espresso should extract between 27 – 35 seconds.
Tamping – Apply a consistent, even pressure when tamping ground coffee in the portafilter. Uneven or loose grounds can lead to poor coffee extraction and weaker crema. Pulling – Aim for a balanced extraction of about 25 to 30 seconds. Shots pulled with too much water tend to produce thinner crema layers.
However, too long of a shot (over 40-45 seconds) can lead to over-extraction, which introduces excessive bitterness and a dry aftertaste. The goal is to find the right balance based on your beans, grind size, and espresso machine.
Espresso machines typically last 5 to 15 years, with proper care significantly extending their life. The type of machine matters, with manual models often lasting longer (15-20+ years) than super-automatic ones (4-8 years).
The "2-hour coffee rule" suggests waiting 90 minutes to 2 hours after waking up to drink your first coffee, aligning caffeine intake with your body's natural cortisol (alertness hormone) cycle for better energy, reduced crashes, and improved efficiency, as cortisol peaks shortly after waking. While some recent research questions the necessity, many experts and users find delaying coffee allows for more effective alertness by letting natural wakefulness occur before adding stimulants, potentially building less tolerance and avoiding afternoon slumps.
A coarse grind extracts more slowly, while fine grinds extract more quickly. So, if you're thinking “Why does my coffee taste bitter?”, you've likely over-extracted. Shorten the brewing time or try a coarser grind. If your cup tastes thin, weak, or sour, you've likely under-extracted.
The Golden Rule
A reliable method for judging your extraction times is by following the “Golden Rule” which states that a double shot of espresso should result in about 2-2.5 fluid oz and take about 20-25 seconds to extract.
There is no standard. A double can be virtually anything pulled with a double or triple basket in a size range of 14 to 115 grams of liquid espresso.
No, 20g of coffee for an espresso dose isn't too much; it's actually a very common dose, especially for a double shot in many cafes, fitting within the typical 18g-22g range for balanced flavor, though some might prefer less or more depending on the bean and desired strength. It's considered a standard dose for achieving a balanced 1:2 brew ratio (e.g., 20g in, 40g out) for a strong, flavorful shot, but it can yield significant caffeine, so adjust to your preference.
One of the primary culprits is often the machine's pump. Like any mechanical component, with time and consistent use, a pump can wear out, fail, or start malfunctioning, thus impacting the pressure it generates. Another common cause is scale buildup. Hard water, when heated, tends to leave behind mineral residues.
While 9 bars is ideal, good espresso can be made within a range of 7 to 11 bars. Some modern machines allow "pressure profiling," where pressure changes during brewing. This flexibility can help baristas fine-tune their extractions for different coffee beans and desired flavor profiles.
Using too much coffee can make it difficult for water to penetrate and pass through the coffee puck, while too little coffee can result in a fast, under-extracted shot. The correct dose depends on your espresso machine's basket size and design, as well as the coffee's roast profile and age.