Why is My Brewed Coffee So Weak? What Causes Under-extraction in Pour-over Coffee? Does the Coffee-to-Water Ratio Affect Coffee Strength?

Bland! Bland! Bland!!

Attention! This isn't a frog croaking, but rather a friend's exclamation after tasting a cup of coffee that's as bland as water. Of course, FrontStreet Coffee doesn't exclude the possibility that it might be some single person

It's quite common for brewed coffee to taste either too strong or too weak. This happens not just to beginners, but even experienced coffee professionals who have been in the field for years may occasionally brew coffee that doesn't suit their taste. So, beginner friends shouldn't worry - this is a "common occurrence." Compared to overly strong coffee, brewing coffee that's too weak and watery is a situation that many beginners encounter more frequently. So how should you adjust when this happens? It's okay if you don't know~ FrontStreet Coffee will share today what causes brewed coffee to be bland and what the corresponding solutions are!

Why Does Brewed Coffee Taste Weak?

When you think coffee tastes bland, it means there's a lack of substances in this cup of coffee that cannot support sufficient flavor expression, resulting in the unpleasant experience of bland, hollow-tasting coffee. There are two factors that can trigger this situation. The first one is what we commonly refer to as: "under-extraction."

Under-extraction

When we extract coffee, we all apply extraction formulas corresponding to that specific coffee bean. Because not all substances in coffee are desirable, we need to control parameters to limit the release of these undesirable substances. Time, grind size, water temperature, and coffee-to-water ratio are the main parameters we need to control. They are all important complementary elements that work together. During the extraction process, they provide different extraction efficiencies from different angles, allowing water as a solvent to appropriately dissolve flavor substances.

And if, one parameter in this formula deviates, it will directly affect the overall extraction efficiency, which in turn prevents the water as a dissolving agent from extracting sufficient substances. Then the coffee will have insufficient substances, leading to unremarkable flavors and unclear taste - this is what we often call "under-extraction." Besides tasting bland, under-extracted coffee may also have undesirable negative experiences such as saltiness and astringency.

This kind of problem is easy to solve - just find the factor affecting extraction and make corrections! FrontStreet Coffee still suggests using time as the judgment standard. For example, FrontStreet Coffee brews 15g of coffee beans using hot water, with brewing time set around 2 minutes. When the brewing time is much shorter than two minutes (difference exceeding 10 seconds), it means the grind is likely too coarse. At this point, we need to adjust the grind to be finer, which can correct the under-extraction problem. And if the time exceeds two minutes but still tastes bland, then it's likely caused by water temperature being too low. At this point, appropriately increasing the water temperature can improve the under-extraction situation. (Note: Everyone uses different equipment and amounts of coffee. FrontStreet Coffee here follows their own equipment and coffee amounts to set the extraction time, so 2 minutes is only for reference~)

But if, the grind size or water temperature is in a situation where it cannot be adjusted, then we can correct the lacking extraction efficiency by increasing other parameters. For example, if the grind is too coarse, but because it's pre-ground or the grinder can't be adjusted any finer, then we can choose to increase the brewing water temperature or extend the extraction time (both segmented brewing and changing the dripper can solve this),以此来得到更高的萃取率，减少研磨不够细带来的影响，以此类推，其他方面出现类似的情况也是一个道理。

Concentration Too Low

Another situation that can cause bland coffee is: coffee "concentration too low," which is somewhat different from under-extracted coffee. As FrontStreet Coffee mentioned in yesterday's article, because the flavor substances in coffee are limited, when we use too much hot water for extraction, not only will we extract undesirable substances like off-flavors, but it will also dilute the coffee's concentration. Because there are only so many substances, the more water you add, the more diluted it becomes.

(The image shows a comparison of coffee extracted using 1:17 and 1:15 coffee-to-water ratios respectively. You can clearly see that the coffee on the right is stronger because it uses less water, with a deeper liquid color. The coffee on the left, because it uses more water, has its concentration diluted, resulting in a lighter liquid color.)

This situation is easy to solve! First, let's taste this bland coffee to see if there's over-extraction - whether there are off-flavors or obvious bitterness in the coffee. If there are, then we only need to directly reduce the coffee-to-water ratio to correct the bland effect. For example, reducing from 1:17 to 1:15, without worrying about whether extraction needs to be corrected. And if there are no off-flavors or bitterness in the coffee, it means that when we correct the coffee-to-water ratio, we also need to simultaneously improve the extraction efficiency of other coffee parameters. Otherwise, after shortening the coffee-to-water ratio, the extraction time will also decrease accordingly. Time is also an important member of the extraction formula. When using a 1:17 coffee-to-water ratio, if the coffee doesn't show negative flavors like off-flavors or astringency, it indicates that the 1:17 ratio combined with other parameters has an overall extraction efficiency that's just right! At this point, if we directly adjust the coffee-to-water ratio, it means the extraction efficiency will be reduced, and the coffee is likely to show under-extraction. So we need to improve other extraction parameters to make up for the extraction efficiency!

In summary, we need to understand the underlying logic of coffee extraction. As long as we thoroughly understand the extraction logic, then no matter what situation our brewed coffee encounters, whether too strong or too weak, we can immediately identify the problem and correct it in a timely manner~

- END -

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473