One of the big challenges when brewing a cup of coffee is to hit the right point of extraction, what you get is simply awesome and, once you get to know it, well, it changes coffee forever. But while it is a challenge to hit the right spot of extraction I’ve noticed that the more common mistake is for people to overpass it and get over extracted coffee.
If you want to go a little more in depth on the components in coffee and how they dissolve in the water to get under or over extracted coffee, you should read my post on how coffee is brewed. But here we will cover how to recognize when your coffee is over brewed and how to avoid it the next time you make coffee.
How to know if your coffee is over extracted?
There are a few signs that will tell you that you over extracted your coffee. I will try to cover them as clearly as I can.
The first and most obvious one is bitterness, the bitter compounds are some of the last compounds to get extracted from coffee after it goes in contact with water, and they usually start dissolving once all the good stuff has dissolved. So if your coffee tastes bitter, it is the first sign that your coffee is over brewed. That’s why I said it is a very common mistake, most people actually describe coffee as a bitter drink.
Another thing that you might notice when over extracting coffee is that it feels dry. Instead of having this mouth filling sensation that a good coffee should give, it feels dry in your mouth, with a kind of roughness to it.
This one is pretty hard to describe, but when you drink an over extracted coffee it leaves you with a feeling of “wanting more”, it’s like all the goodness (life) has been taken out of it. Even if it is something that you might drink because it’s there, it will definitely not be something that you enjoy.
You can try this experiment to have a good understanding of how an over extracted coffee can taste like. You can purposely over extract some coffee and look for these descriptions I mentioned. There are several ways you can do it. You can make a french press with a finer ground and leave it sitting for more time, perhaps 8 or 10 minutes, and then taste it. This will surely overpass the ideal extraction point by far.
If you have a pour over coffee maker you can do it as well with a very fine grind, and probably add a bit more water than you are used to, the fine grind will make the filtration longer which will over extract your coffee.
Of course these experiments will make are EXTREME over extraction, but it will tell you clearly how it tastes like so that when you drink a slightly over extracted coffee, you will be able to recognize it.
How to correct over extracted coffee
Once you recognize that your coffee tastes over extracted, there are things you can do to correct it the next time you brew. It is helpful to understand how coffee is extracted. But here is a list of things you can try next time to avoid over extraction.
Use a coarser grind. When coffee is ground, particles are smaller which means it’s going to take less time to extract whatever is in them. So what this means, is that with a coarser grind you are going to extract more slowly, and if you do it for the same amount of time, fewer components are going to be dissolved in your water.
If you are using a pour over method, or making espresso, there is a double effect on making the grind coarser, because additional to components extracting more slowly, since the particles are bigger they will let the water through quicker. This means that if you use the same amount of water, your brew time will be less. This is OK, my only advice is that if you are using these types of methods make a very small adjustment in the grind, so you don’t run the risk of under brewing due to this double effect. Another thing that you might want to think of in this case is to add more water to make the brew time the same as before, but this is only a good idea if you also want your coffee less concentrated.
Brew for less time. Of course if you are over extracting you might think of doing it for less time. Which is very simple if you are using an immersion method such as the french press, this means you stop extracting before you come to over brew. But with pour over or espresso, as I explained before, the way to reduce time without changing the grind is to add less water. This is totally OK, the difference is that you will have a more concentrated coffee.
Use less water. This one might be a little intuitive after the last two, if you use less water the brew time will reduce, for pour over and espressos and you will avoid over extracting. In a french press what happens is that if you use less water, it will saturate faster, and this slows down extraction. Imagine if you add a lot of coffee and just a little of water, this water will not necessarily come out as a very strong coffee, it reaches a point of saturation where it stops dissolving components.
There are also some mistakes that are common and can lead you to an over extracted cup, I will mention them so you can watch out.
- To leave the filter on top of the cup after you are finished, in pour over methods… The last drops of water remaining in the filter are filled with the bitter compounds, you don’t want them in your cup.
- To leave the coffee inside the french press after plunging, before serving it… French press coffee should be served right away, because even if the ground remain compacted at the bottom, they will keep on releasing components to the water.
Don’t go to far
Remember that these solutions must be slight tweaks, because if you go too far, you might end up with an awful cup of under extracted coffee, which you also don’t want at all. Of course if your coffee is way too bitter you might want to start with a bigger tweak, but this is usually not the case. Under extracted coffee is almost as unpleasant.
As I always say, this is still question of taste, I am sure that nobody likes an extremely over extracted cup, but depending on your taste you might enjoy a little bitterness in your morning drink. I personally like to avoid it all the way, let me know what you think!!!