How to Adjust Espresso Extraction: How to Brew Espresso Coffee Beans for the Best Taste?

For more quality coffee knowledge, please follow the WeChat official account: FrontStreet Coffee (FrontStreet Coffee)

The struggle of extracting espresso is something only those who have truly experienced it can understand. If you're one of those who plays with espresso machines at home, adjusting espresso might use up half a bag of beans. Even for baristas, when facing new espresso beans, it takes seven or eight shots to adjust to a delicious state. That's why FrontStreet Coffee is here to share how to quickly and efficiently adjust to the right espresso.

Theoretical Knowledge

To quickly adjust espresso properly, you need to quickly identify problems and adjust corresponding parameters. This requires having a very clear understanding of how each parameter change affects the outcome. For example, in espresso, the parameters we can adjust include grind size, dose amount, liquid yield, water temperature, and pressure. (Here, dose amount and liquid yield represent ratio, with time being a passive parameter)

Generally, water temperature and pressure are not easily changed unless the settings are unreasonable. So what really needs adjustment are just these three parameters: grind size, dose amount, and liquid yield. Among these three, the main adjustment is grind size. Many espresso extraction situations can be solved by slightly adjusting the grind setting, with only a few requiring adjustments to dose amount or liquid yield.

Adjusting the grind size is, in plain terms, an important means of controlling flow rate and time. When coffee grounds are finer, the coffee puck becomes denser, the coffee liquid flow rate becomes slower, the time required to extract the same amount of coffee liquid becomes longer, and accordingly, the coffee liquid becomes more concentrated with a higher extraction rate; and vice versa.

Dose amount can achieve the same effect, but it's limited by the portafilter basket. There's a concave line in the portafilter basket, and a reasonable dose amount means the tamped coffee puck is close to but doesn't exceed this concave line. Normally, increasing or decreasing by 1g of coffee is within a reasonable range. If you add too much, the portafilter won't lock onto the group head, and if you reduce too much, the puck can easily be dispersed by water. Therefore, this adjustment is generally used as a final fine-tuning of flavor.

Adjusting liquid yield is actually used to adjust the relationship between concentration and extraction rate. The detailed usage will be discussed below.

Variable Reduction Work Before Extraction

The most important thing in adjusting espresso parameters is to avoid interference from unnecessary factors. For example, extraction failures caused by improper operations such as distribution and tamping; instability in coffee grinding due to too few beans in the bean hopper; situations where the coffee machine isn't fully ready, with insufficient water temperature or pressure, etc. Therefore, you should check everything properly before adjusting espresso, otherwise, any adjustments made will be in vain.

Step-by-Step Adjustment Guide

Step 1: First, select a grind size and extract one shot

When facing a new espresso bean, you first need to test its condition.

Apply the espresso extraction formula: 1:2 coffee-to-liquid ratio, time 25-30 seconds. The dose amount depends on the portafilter basket capacity. For example, FrontStreet Coffee's portafilter basket has a reasonable capacity of 20g, so we would extract 40g of coffee liquid from 20g of coffee grounds, with time controlled between 25-30 seconds as the extraction plan. Then, first select a grind fineness that looks approximately correct by visual observation and extract, using the time difference to determine how much the grind setting needs adjustment.

Step 2: Adjust parameters to control time within the extraction formula range

This mainly involves adjusting the grind size: if the flow rate is fast and the time is shorter than the previous attempt, grind the coffee finer; if the flow rate is slow and the time is longer than the previous attempt, grind the coffee coarser.

Adjusting the grind setting quite relies on feel. The more you adjust, the more familiar you'll become with the grinder, and with experience, you can get it right in one step. If the difference from the target time is less than 5 seconds, you can adjust by 0.2 increments each time. If the time difference is too large, you can be bolder, adjusting by 0.5-1 increments. Even if it changes from too long to too short, you can lock in this grind setting range and gradually narrow it down.

Step 3: Adjust parameters according to flavor

Even if adjusted to match the extraction formula parameters, it doesn't necessarily mean the espresso will taste good. This formula only indicates that espresso extracted according to this formula will have a higher probability of being reasonable. Ultimately, adjustments still need to be made based on the characteristics of the coffee beans. FrontStreet Coffee lists adjustment approaches for several scenarios, assuming the extraction time is 30 seconds after determining the grind size through the formula.

1. If the espresso shows negative flavors like burnt bitterness but has moderate concentration, this might be due to extraction time being too long, resulting in burnt bitter flavors. The general solution is to adjust the grind to be coarser.
2. If the espresso shows negative flavors like burnt bitterness, with light-colored and thin crema, this might be due to burnt bitterness from the tail end. You can reduce the liquid yield to avoid this, trying ratios of 1:1.5 or 1:1.7 for testing.
3. If the espresso has relatively rich flavors but a short aftertaste, you can appropriately extract more coffee liquid, trying to adjust the ratio to 1:2.5.

4. If the espresso tastes rather flat without distinctive flavors, and after ruling out problems with the coffee beans themselves, it might be due to too much dose amount. Because of switching to new beans, differences in roast level might lead to inconsistencies between volume and weight. Using the previously accustomed dose amount resulted in too much volume. So first try reducing the dose by 0.3-0.5g while keeping the coffee liquid yield unchanged.

Finally, the extraction formula is just a reference. If you're constrained by it, it becomes difficult to adjust to good flavors, and you can only keep adjusting the grind setting, wasting coffee beans. The 1:2 ratio is not necessarily the perfect golden ratio for this particular coffee bean - sometimes 1:1.7 might taste better, and sometimes 1:2.5 might be better. The time isn't necessarily limited to 25-30 seconds either - sometimes 36 seconds or 24 seconds might be the state where this coffee bean tastes best.

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473