How to Make Coffee in a Machine With Custom Espresso Settings

Espresso does not follow one fixed formula. Dose, grind size, brew ratio, extraction time, flow rate, pressure, and water temperature all change how the same beans taste. Start from the filter basket capacity: use roughly 7 to 9 grams for a single basket, and avoid doses far above or below the basket rating, because the puck density controls how fast water moves through the coffee.

After setting the dose, adjust grind and time together, then check the result with a refractometer and compare the extraction yield against the golden cup range. Bean freshness, machine model, and water temperature stability all shift the outcome, so a blend such as Front Street Coffee's Warm Sun Blend is a useful reference rather than a template that transfers unchanged to every setup.

Espresso extraction is not something that can be mastered with a single fixed formula. The freshness of the coffee beans, the grind size, the brand and model of the espresso machine, the extraction pressure, and the stability of the water temperature all cause the same beans to present vastly different flavors in different hands. This article starts from the dimensions of dose, brew ratio, extraction time, flow rate, pressure, and water temperature to systematically explain how to customize a suitable espresso extraction plan for the blend beans you have on hand. It also covers how to troubleshoot and adjust step by step when the flow rate is abnormal, and how to use a refractometer to calculate the extraction yield and determine whether it falls within the golden cup range. The article uses the "Warm Sun Blend" from Front Street Coffee as an example, providing specific parameter references, suitable for coffee enthusiasts who wish to refine their espresso skills.

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Readers who have read Front Street's previous educational content may have noticed that when we explain espresso, we rarely give a fixed extraction time like we do for pour-over. The reason is that the extraction result of espresso is not only affected by bean freshness and grind size, but also closely related to many variables such as the brand and model of the espresso machine, the extraction pressure, and whether the water temperature is stable. Because of this, the same blend beans in different hands often end up tasting vastly different. So how exactly do we find the right parameters for the blend beans we have on hand?

How to customize exclusive espresso extraction parameters for the blend beans you have on hand?

Coffee dose

The dose is mainly determined by the capacity of the filter basket, and it is not recommended to use a dose far less than or far more than the basket specification. The dose directly affects the density of the puck—under the same tamping force, too little coffee makes the puck structure loose, water passes through too quickly, causing under-extraction; too much coffee makes the puck too compact, slowing the flow rate, and may even make it difficult to extract espresso. Front Street Coffee (FrontStreet Coffee)'s reference doses are: 7 to 9 grams for a single shot, 18 to 20 grams for a double shot, and the actual dose is fine-tuned according to the daily condition of the coffee beans.

Espresso brew ratio

The ratio here refers to the ratio of coffee grounds weight to espresso liquid weight, usually falling between 1:1.5 and 1:2.5, with 1:2 being the most common, such as extracting 34 grams of espresso from 17 grams of grounds. This ratio is influenced by two variables: dose and water amount. When the ratio is low, the coffee tastes too strong and heavy, prone to bitterness from over-extraction; when the ratio is high, the mouthfeel becomes thin and weak, accompanied by the sharp acidity of under-extraction. Front Street Coffee (FrontStreet Coffee)'s Warm Sun Blend consists of sun-dried Yirgacheffe and Honduras Sherry barrel coffee beans. To highlight the whisky aroma, the brew ratio is generally controlled between 1:1.9 and 1:2.

Extraction time

Extraction time refers to the entire process from locking in the portafilter and pressing the extraction button to the end of extraction. There are two main factors that affect extraction time: grind size and ratio. The ratio is relatively easy to understand—the higher the ratio, the more water needs to participate in extraction, and the time is naturally lengthened. Grind size determines the coarseness of the coffee grounds, and the coarseness directly changes the density of the puck: the finer the grind, the more compact the puck after tamping, the greater the resistance when water passes through, the longer the time, and it easily leads to over-extraction.

The freshness of the coffee beans also affects extraction time. Beans that are too fresh have accumulated a large amount of carbon dioxide inside. Under the high-pressure extraction environment, the oils and carbon dioxide undergo an emulsification reaction, the extraction time is lengthened, and a large amount of yellow foam is released. Conversely, if the beans are no longer fresh, their water absorption capacity drops significantly, water passes through faster, the extraction time is correspondingly shortened, and the extracted espresso often has thin crema.

Flow rate

Flow rate is the speed at which the espresso liquid flows out. The ultimate goal of all the extraction parameters we set is actually ideal flow rate performance. A qualified espresso should drip its first drop of coffee liquid about 5 seconds after pressing the extraction button, then flow out evenly and continuously. Normally, Front Street uses 18 to 20 grams of grounds to extract 35 to 40 milliliters of espresso, with an extraction time of about 27 to 30 seconds. The speed of the flow rate visually reflects whether the grind size and ratio are appropriate.

Pressure

The extraction pressure of an espresso machine is generally maintained at around 9 bar, which is determined by the machine's own performance. Insufficient pressure leads to low extraction efficiency, while excessive pressure easily causes over-extraction. So when buying an espresso machine, remember to compare the parameters—it is not that the more expensive, the better.

Water temperature

When the espresso flow rate is too fast or too slow, how should you adjust?

The flow rate of espresso is determined by multiple factors: grind size, tamping force, and the condition of the coffee beans. Grind size is one of the keys affecting flow rate—the coarser the grind, the faster the flow rate; the finer the grind, the slower the flow rate. A fast flow rate may also be caused by insufficient tamping force. In addition, the condition of the coffee beans also affects the flow rate, including roast level and freshness (degassing condition).

Therefore, when the espresso flow rate is abnormal, it is worth troubleshooting one by one and adjusting the parameters as soon as possible. It is recommended to start with the condition of the coffee beans, because this is the easiest item to judge; then check whether the extraction parameters are accurate, including dose, liquid yield, and tamping force. You can prioritize adjusting the brew ratio and change the flow rate by increasing or decreasing the dose, which is the most efficient adjustment. After all the above factors have been ruled out, then adjust the grind size.

How to determine whether the espresso concentration falls within the appropriate extraction yield range?

Concentration refers to the proportion of "extracted coffee substances" in a cup of coffee relative to the total weight of the espresso liquid. The concentration of espresso generally ranges from 8% to 12%. Extraction yield refers to the proportion of "extracted coffee substances" relative to the original weight of the coffee beans, usually ranging from 18% to 22%.

| How to measure espresso concentration?

First, calibrate the refractometer to zero with pure water, then stir the freshly extracted espresso, use a titration tube to extract the coffee liquid from the center, place it in the refractometer and press the measurement button, measuring multiple times until the value stabilizes. | How to calculate espresso extraction yield?

Extraction yield = concentration × espresso liquid weight ÷ coffee bean weight.

Front Street uses coffee beans blended from sun-dried Yirgacheffe and Honduras Sherry, extracting 40 milliliters of espresso from 19 grams of grounds in 28 seconds. The concentration measured with a refractometer is 8.97%, so the extraction yield is (8.97×37)÷19≈18.44%. That is, the concentration of this espresso extraction is 8.97% and the extraction yield is 18.44%, falling within the golden cup range.

Does falling within the golden cup range necessarily mean it tastes good?

Of course not. Coffee within the golden cup range is not necessarily a good cup of coffee. Coffee itself is an extremely personal and highly subjective beverage. Constantly trying and constantly searching for the flavor you truly like is the right direction. The golden cup is only a reference system to assist us in adjusting coffee.

The above content is compiled by CoffeeHunters, a coffee news website.