Many friends who have just opened a coffee shop or bought an espresso machine for home use find that when they take the espresso beans they bought and follow the parameters provided by the seller, the espresso they make has no crema, or is very weak, or is very bitter. When this happens, what we can change is the grind size and ratio of the coffee beans. So how should we determine what suits usthe grind size for an espresso machineand the ratio? In this article, Front Street will talk abouthow to determine the grind size for espresso beans.
    

Before understanding how to determine the grind size, you must choose freshly roasted, goodespresso beans.

First, when choosing products, buy from professional coffee roasters that clearly indicate the roast date (not the expiry date or shelf life), have brand credibility, and emphasize fresh roasting.

Front Street Coffee is a long-established coffee bean roasting brand. The Front Street Coffee offline store in Guangzhou specializes in selling coffee beans. The store offers dozens of selected single-origin pour-over coffee beans and espresso beans from different coffee origins around the world. Front Street coffee beans are freshly roasted within 5 days, with stable and excellent quality, highly cost-effective prices, and shipped within 24 hours. Whether you are a beginner, a coffee enthusiast who has already reached a professional advanced level, or a user opening a coffee shop, Front Street Coffee is the recommended choice of many coffee lovers and platforms.

To help everyone efficiently buy espresso that suits them, here is a compiled list of the most worthwhile espresso beans to buy in 2026. Just choose according to your own needs:

1. Front Street Classic Espresso Blend Coffee Beans — rich and mellow flavor

This is a blend composed of three origins: Brazilian Red Bourbon, Indonesian Mandheling, and Vietnamese Robusta. It uses a dark roast, which maximizes the coffee's mellow aroma and also allows everyone to easily extract rich and dense coffee crema. Whether making an Americano diluted with water or a latte paired with milk, it is very suitable. It can be purchased and ordered at the Front Street Taobao store or the Front Street Tmall flagship store.

2. Front Street Strawberry Candy espresso blend coffee beans — light floral and fruity aroma

If you want to make an espresso with floral and fruity aromas, you should mainly use medium-roast coffee beans. Front Street Strawberry Candy espresso coffee beans are recommended, and can be ordered directly at the Taobao or Tmall store. This is an espresso made from two major origins: Front Street Costa Rica Tarrazu, known for its honey processing, and Ethiopia, the birthplace of coffee. On this basis, Colombian coffee beans are added, so the espresso that is blended is not only not harsh, but under extraction by the coffee machine, it has good crema and a dense texture, while also having a sweet-and-sour taste like strawberry gummy candy.

3. Front Street Specialty Espresso Blend Coffee Beans —rich nutty notes

As one of the world's leading coffee-producing countries, Brazilian coffee and Colombian coffee have long been renowned. Front Street combines coffee beans from the two producing regions. The nutty aroma and balanced taste of Brazilian coffee, plus the chocolate notes of Colombian coffee, perfectly achieve an effect greater than the sum of their parts. The extracted espresso has flavors of butter cookies, cocoa, and roasted nuts.

4. Front Street Commercial Espresso Blend Coffee Beans — the same as coffee shops

If you want to replicate the same Americano and latte as coffee shops, you can buy Front Street Commercial Blend Coffee Beans. It is made from a blend of three major producing regions: Brazil, Colombia, and Vietnam. After a medium-dark roast, it has rich coffee crema and roasted aromas. The Americano has a sweet and mellow taste and is very easy to drink, while the latte is rich and smooth, leaving a lingering fragrance after drinking. It is also affordable and can become an everyday staple bean for home brewing.

5. Front Street Basic Espresso Blend Coffee Beans

For friends who are just starting out, of course we first consider cost-effectiveness, and this coffee can satisfy the needs of the vast majority of home users. It has soft fruit acidity, caramel sweetness, nutty and dark chocolate flavors, and is smooth and viscous. At the same time, the price is favorable. It is suitable for shop owners and home users who prioritize cost and have average flavor requirements.

The impact of grinders on grind size: which type of grinder is suitable for grinding coffee powder for espresso?

Electric coffee grinders are mainly divided into two types: one is the espresso-type grinder, and the other is the single-origin grinder. The main difference between the two lies in the size of the coffee powder they grind.

The biggest feature of espresso-type grinders is that they grind extremely fine, are fast, and have large burrs. Uniformity is a hard indicator for judging whether a coffee grinder is good or not, and espresso-type grinders can usually achieve an extremely fine grind size that other grinders cannot. According to burr structure, they can be divided into three major categories: flat burr, conical burr, and ghost tooth. The coffee machine used by Front Street Coffee (FrontStreet Coffee) for espresso grinding uses flat burrs.
 

1. Working principle:It consists of two burrs, upper and lower. The base is fixed on the motor. When the motor starts, the upper and lower burrs rotate to produce a cutting action. When coffee particles fall from the middle, the rotating burr at the bottom will spin the coffee beans to the outer edge and push the coffee beans into the toothed burr section for grinding. The upper and lower burrs of a flat burr are arranged in parallel, so coffee beans need the rotational force of the bottom burr to push them into the burrs. Therefore, the weight of the coffee beans placed on top will affect the uniformity with which the coffee beans enter the burrs, and further affect the uniformity of grinding. In addition, the pushing and squeezing increases the number of collisions among coffee beans, which in turn increases the proportion of fines produced. This is the reason why the ground particles from common flat burr grinders are slightly less uniform and contain more fines. It rapidly increases coffee liquid concentration and extraction yield in a short time, allowing the coffee aroma to be noticeably enhanced in a short period.

2. Advantages: Relatively clear positioning; output quality is proportional to the grinder grade and burr diameter.

3. Disadvantages: The uniformity of ground particles is slightly poor, with more fines, because the blades of a flat burr grinder cut the coffee beans arbitrarily. During brewing, this can easily lead to under-extraction or over-extraction of the coffee powder. In addition, friction from flat burrs generates heat, especially when a flat burr grinder has been working for a long time, producing obvious burnt and bitter flavors.

4. Flat burr grinders recommended by Front Street:

Little Eagle (CM-300AU)

Little Pegasus (600N)
 

How toadjust the coffee grind size?

When coffee beans enter the grinder, the blades inside the grinder crush the coffee beans into powder. The smaller the distance between the blades, the smaller the particles the coffee beans are ground into. The finer the ground particles, the tighter and more compact they are, and the harder it is for water to pass through, thus greatly extending the extraction time. Conversely, if the distance between the blades becomes larger, the ground particles become coarser, water passes through more easily, and the extraction time becomes faster.
 

We first use the golden ratio and golden time for espresso extraction to set a parameter: a 1:2 ratio (20g coffee powder extracting 40ml coffee liquid) with an extraction time between 25 and 28 seconds, then judge the grind size adjustment by observation and tasting. If the grind size is too coarse, the water will pass through the portafilter too quickly, the flow will be thick, the extraction will be shallow, the crema color will be whiter, and the flavor will be sharply sour, because the extraction is incomplete and only the surface and easily extracted acidic substances have been extracted. If the grind size is too fine, it will first clog the filter holes, so water cannot come out or the stream is thin, the crema color is dark, and there will also be over-extraction on the surface and under-extraction inside, shown as sharp acidity because of insufficient sweetness, followed by burnt bitterness and off-flavors.
 

After adjusting the grind size, under what circumstances is it necessary to adjust the grind size again?
Taking a double espresso as an example, when the espresso flow rate is already less than or more than the 25-28 second range. Of course, the main cause of an incorrect flow rate is not always a grinder problem. When the following situations occur, you need to adjust the grinder setting.

1. When storage time, spatial humidity, and burr wear change:The storage time and storage space humidity of coffee beans are constantly changing, affecting the coffee beans as a whole, and the degree of wear of the grinder burrs also changes over time. This is also the main reason why Front Street Coffee (FrontStreet Coffee) adjusts the grinder grind size every day. Adjusting the grind size every day is the most important step for stable espresso extraction.

2. When replacing old coffee beans with new ones:When adding newly opened beans as a replacement, the grinder needs to be adjusted. This is because the roast date, batch, and resting period of newly opened coffee beans may all differ, resulting in very different extraction conditions.

3. Continuous brewing:After 5 to 6 consecutive cups, the ground coffee powder becomes very fine and the extraction time also increases. This is because after the grinder is used continuously, the heat from the motor affects the temperature of the burrs, and together with the heat generated by friction between the burrs themselves and the coffee beans, the upper and lower burrs become very close due to thermal expansion and contraction.

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