How to Adjust Espresso Grinder Settings: Illustrated Guide to Coffee Grinder Adjustment and Espresso Parameters

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Why Do Coffee Shops Need to Adjust Their Grinders Daily?

Coffee shops need to adjust their coffee grind settings daily, with some even making adjustments every few hours. Aren't extraction parameters fixed? With the same machine, same coffee beans, and same extraction parameters, could different coffee still result? In fact, while these three elements may appear unchanged to the naked eye, they are actually undergoing subtle changes daily. This is similar to the principle of boiling a frog in warm water—if a coffee shop fixes its extraction parameters, changes might not be noticeable for a day or two, but eventually quantitative changes lead to qualitative changes. That is, one day you might suddenly find your coffee has become unpleasant, which would be counterproductive. So how does FrontStreet Coffee adjust their grinder?

The Significance of Adjusting the Grinder

To customers, machines like coffee machines and grinders are considered fixed assets, but to coffee professionals, they are consumables. The brewing pipes and steam boilers of coffee machines, as well as the grinder burrs, all undergo gradual wear and tear during operation—these are all variables. Therefore, baristas carefully maintain them daily and perform "major overhauls" periodically.

Coffee beans are even more susceptible to change. Freshly roasted coffee contains very active carbon dioxide, and what we call the flavor period is actually the degassing period of coffee beans. Initially, coffee beans release excessive carbon dioxide, then gradually stabilize and release it slowly over time. When coffee no longer releases gas, it can be said that this coffee has lost its freshness. In other words, the flavor of coffee beans is constantly changing, especially after an entire night, when their flavor state changes even more noticeably.

Understanding Grind Size and Extraction

When coffee beans enter the grinder, the blades inside crush them into powder. The smaller the distance between the blades, the finer the coffee beans will be ground. The finer the grind particles, the more compact and dense they become, making it more difficult for water to pass through, thereby significantly extending the extraction time. Conversely, if the distance between the blades increases, the ground particles become coarser, water passes through more easily, and extraction time becomes faster. To give a simple example, think of rocks versus fine sand—water flows through rocks much faster than through fine sand because there's more space between rocks for water to pass through quickly. Therefore, correct grinding is crucial, as particle size directly affects extraction quality.

How to Judge Powder Quality

Observe the coffee powder—high-quality coffee powder should appear powdery with a granular texture. If the coffee powder is quite soft, like flour, it indicates the powder is fine. Conversely, if the coffee powder feels tough and coarse, it means the powder is too coarse.

FrontStreet Coffee's Grinder Adjustment Tutorial

Different grinders have different adjustment scales, so you should check your coffee grinder model and carefully read the instructions to determine the scale's direction and magnitude. Generally, if you maintain the habit of checking grinder settings regularly, only very small adjustments are needed. Moving the dial scale within 3 millimeters can change the fineness of the powder. Although 3 millimeters is a very small number, the grinding time for the same coffee beans will change by 3-5 seconds.

Specific Operation Steps

Determine the direction you need to adjust (finer or coarser). Ensure there are enough coffee beans in the bean hopper and that the valve between the bean hopper and the grinding burrs is open, allowing coffee beans to fall smoothly into the grinding area.

Turn on the grinder for 10 seconds and discard the coffee powder (this is coffee powder with unadjusted grind settings).

Use the resulting coffee powder to make a cup of coffee, ensuring accurate dosing, distribution, and tamping steps. For example, FrontStreet Coffee's espresso extraction standard is a coffee-to-liquid ratio of 1:2, with extraction time between 25-30 seconds. Therefore, during testing, we need to adjust the grind to achieve the parameters we want to use.

FrontStreet Coffee uses time tests to check the stability of espresso parameters during each extraction. For example, if the extraction time is 28 seconds after adjusting the grinder in the morning, but by noon the extraction time has changed to 22 seconds, then the grinder needs to be adjusted finer to bring the time closer to 28 seconds. Of course, time is only a reference standard—the most important thing is to confirm through tasting.

Adjusting Electronic Grinders

Adjusting electronic grinders mainly targets two variables: dose amount and grind degree. These two variables are interrelated—changing one will also affect the other.

Typical electronic grinders adjust the grinding and dosing time based on pre-set dose amounts (please note that grinders adjust dose amount based on time, not weight). If you're not satisfied with the quality of your coffee, the first thing you should do is determine whether the problem lies with the dose amount or the grind degree.

Generally, with correct dosing, distribution, and tamping, the distance between the coffee puck and the outlet should be 5-6 millimeters. If the puck height is not within this range, you should try adjusting the grinder's dose amount (i.e., grinding and dosing time). When adjusting the dose amount, each adjustment should be between 0.2-0.3 seconds. After each dose adjustment, you need to re-evaluate the coffee quality.

The most difficult part of adjusting electronic grinders is that when you adjust the grind parameters, the distance between the grinding burrs changes accordingly, and this distance change directly affects the grinder's dose amount—that is, the grinding and dosing time. If you want to make the grind finer, the distance between the burrs becomes closer, and fewer coffee beans will pass through the burrs in the same amount of time. Conversely, when the distance between burrs increases, more coffee beans will pass through the burrs in the same amount of time.

Therefore, when adjusting electronic grinders, we should first understand the relationship between dose amount and grind degree. Since these two variables change as one variable changes, we need to continuously adjust and test to achieve the best results.

Conclusion

Every small detail change in the grinder can have a huge impact on the overall quality of the coffee. Therefore, as a barista, you should re-measure and adjust the grinder daily to ensure perfect coffee quality.

To master the water-to-coffee ratio, you can use a constant coffee amount (18 grams, for example) during practice and try pairing it with different total coffee weights, then compare the differences in taste, clarity, and body between various ratios. You need to decide on the final water-to-coffee ratio based on personal preference.

Only through continuous practice and exploration can you create espresso that truly suits you.

For more specialty coffee beans, please add FrontStreet Coffee on private WeChat (ID: 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