What Is a Coffee Bed? Does Bed Depth Reveal Coffee Quality? How to Achieve a Perfect Depression in Pour-Over Brewing

As we all know, when we finish brewing pour-over coffee, the coffee bed will be revealed as the water level drops. If the coffee bed presents a deep and uniform depression at this time, it will be something worth showing off.

But I believe everyone knows clearly that the shape of the coffee bed at the end of brewing doesn't have much to do with whether the coffee tastes good or not. It mainly conveys to us information about the pouring method and the coffee grounds. Currently, there are mainly six common states of coffee beds, from which we can interpret different messages. Therefore, FrontStreet Coffee would like to share what these different forms of coffee beds are expressing!

1. Coffee Bed with a Deep and Uniform Depression

"Contestant number one" is the deep depression coffee bed that's often shown off! The appearance of this type of coffee bed means that during pouring, we used a large water flow to raise the coffee bed. Moreover, the water flow injection position is mainly concentrated in the center, which allows for the formation of such a depression located in the center of the coffee bed with uniform size.

In addition to the injected water flow, there are other factors that affect the formation of the deep depression in the coffee bed: the amount of coffee grounds determines the depth of the depression—more coffee grounds mean the coffee wall can pile up higher, allowing the depression to sink deeper; the density of the coffee grounds determines the size of the depression—lower density makes it easier to form a depression, so typically, dark roasted coffee grounds are the main candidates for forming deep depressions; the number of pour-over segments determines how prominent the coffee bed appears—fewer segments make the depression more obvious. Therefore, based on the size of the depression in the coffee bed, we can interpret so much information.

2. Coffee Bed with a Deep but Offset Depression

Of course, many times although the depression in the coffee bed might be deep, it might be somewhat uneven. As shown in the picture, it doesn't present a uniform vertical downward shape, but rather a manifestation of shifting to the left or right.

This type of coffee depression occurs because when we pour water, the water column doesn't form vertically before injection. The pour-over kettle used for hand-pour coffee will have different spout designs depending on the manufacturer, and these different spouts will cause certain changes in the water column poured from the same angle. For example, with the same capacity and water volume, a downward-curved eagle-beak spout will more easily pour a vertical water flow than a straight flat spout.

When we use a spout that makes it difficult to inject vertical water flow, we need to adjust our pouring method accordingly, otherwise hot water will be injected at an angle, causing coffee grounds in certain directions to receive more extraction, thus creating uneven extraction. Additionally, hot water might break through the coffee wall due to excessive impact force and escape directly through gaps, forming bypass water that affects the overall concentration of the coffee.

Therefore, when we see a similar coffee depression during a brewing session, we must pay attention to adjusting the pouring method to avoid frequent occurrences of uneven extraction.

3. Flat Coffee Bed with Coffee Walls

Sometimes, the coffee bed we brew might not form ups and downs of depressions, but rather will be relatively flat overall, like a flat surface.

This type of flat coffee bed with small sections of coffee walls, as shown in the picture, mainly has three formation reasons: first, not raising the coffee bed, with pouring mainly consisting of large circles, causing the coffee grounds to have no opportunity to disperse and thus unable to form depressions; second, too many pour segments! When there are too many pour segments, the coffee grounds will have reduced adhesion due to saturation. As the number of pours increases, the coffee grounds will gradually detach from the filter cup wall due to increased weight and fall to the bottom. When all the coffee grounds attached to the filter cup wall have fallen off, it will form the appearance in the picture, with only a small amount of coffee grounds sticking to the wall, while the rest lies flat;

Additionally, the density of the coffee grounds is too high! When the density of coffee grounds is too high, they are not easily moved by water flow. Even if the coffee bed is raised, they will quickly sink down, thus forming such a flat coffee bed.

4. Flat Coffee Bed Without Coffee Walls

This type of coffee bed is completely different from the previous one! The coffee bed has a flat bottom, and almost no coffee grounds are attached to the surrounding filter cup walls!

This type of coffee bed occurs because when we pour water, we pour hot water onto the filter cup wall, causing all the coffee grounds attached to the wall to be washed down. If using a filter cup with many ribs (such as V60), this pouring method will promote the birth of bypass water. Hot water, due to its strong penetration, will escape directly through the gaps created by the ribs. Then the coffee will be diluted due to the generation of bypass water, and at the same time, because there isn't enough hot water for extraction, the coffee will easily exhibit under-extraction.

So when this type of coffee bed appears, we also need to pay attention to our pouring method to reduce the occurrence of uneven extraction and bypass water phenomena.

5. Layered Coffee Bed

Whether it's a deep depression or flat bottom, we might see this type of coffee bed, with a barrier around the cup wall separating the coffee wall from the coffee bed.

This situation is similar to the second type of coffee depression because our improper pouring caused hot water to concentrate on extracting these edges. Similarly, the appearance of this situation will also cause the coffee to easily exhibit uneven extraction. We need to pay more attention during brewing and avoid pouring hot water on the edges.

6. Muddy Pit

The so-called muddy pit refers to a coffee bed that looks very muddy with a deep depression, as shown in the picture below.

There's only one main reason for this type of coffee bed, and that is too many fine particles. When there are too many fine particles, not only will the coffee bed appear in this form, but it will also easily cause your coffee to be over-extracted due to excessive brewing time.

In this situation, we need to find the cause of the large amount of fine particles and solve it. Grinding too fine, poor quality grinder are the main sources of large amounts of fine particles. If grinding is too fine, we can solve it by adjusting to coarser settings. If it's a quality issue with the grinder, then we need to solve it by using a sieve to remove fine particles or by replacing the grinder~

Finally, FrontStreet Coffee still wants to emphasize: the shape of the coffee bed doesn't have much to do with whether the coffee tastes good or not. Don't miss out on a cup of delicious coffee just because you're judging coffee by its appearance~

Important Notice :

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