Making the perfect cup of coffee can be hard. Sometimes your espresso might be bitter and other times it might be sour and you don’t know how to fix it. In this article, I will walk you through a few things that can help eliminate these unpleasant flavors, because bad espresso is not the way to start your day.
Common reasons for your espresso being either sour or bitter include:
- Using the wrong amount of water
- Beans ground too fine or too coarse
- Over and under-extracting
- Old or bad-quality beans
- Improper tamping
Before we go on, let’s first establish what espresso should be like, and then we look at all the factors that can influence that perfect taste.
What is Espresso?
Before we can even talk about the mistakes in espresso making, we first have to establish what the perfect espresso shot is and how it should taste.
Angelo Moriondo invented the first espresso machine in the early 1900s because he wanted to be able to serve coffee faster to his guests. However, he didn’t just decrease the brewing time of a cup of coffee, he also blessed us with coffee that makes our taste buds yearn for our next cup of coffee.
How to Make Espresso
Espresso is made by forcing hot water through fine-ground coffee beans that are in a filter basket and is usually served in a small cup. The reason that we use fine-ground beans is that it helps with making a stronger shot because the finer the grind, the more water comes into contact with it. But beware of not using beans that are ground too fine, that will make your coffee bitter.
Espresso needs an intense aroma and flavor. It should be rich and smooth and have velvety crema (a kind of layer of foam) on top.
Neither espresso that is too sour nor espresso that is too bitter is a good thing. There should be a good balance between the two.
For general reference, if you think of sour, think lemon juice, and for bitter think 98% dark chocolate.
If you want to know what either sour espresso or bitter espresso taste like pull a shot, but let it pour into two separate cups. Fill the first cup during the first 10-15 seconds of the extraction process and the other during the 10-20 seconds that are left.
The first will be sour and the second will be quite bitter. The reason for this is that the sour notes are extracted first followed by the bitter compounds later.
You can spot sour espresso a mile away without even tasting it. The espresso will have a light color. Also, the crema will be thin and light and will disappear quite fast. You can also see it in the puck which will be quite dry after extraction.
As a general rule of thumb, under-extracting your coffee will make your espresso taste sour and weak. The reason for this is that if the extraction time is too short, the coffee oils that are responsible for a good coffee flavor, haven’t had time to be extracted yet.
Why Does Your Espresso Have a Sour Taste?
There are quite a few reasons why your espresso might taste sour. Here is a list of the main reasons that your espresso might taste sour:
- A too coarse grind
- Bad tamping
- Too low water temperature
- Not enough coffee in the basket
- The wrong kind of bean
- Beans that were roasted too recently
How to Fix Sour Espresso?
Longer Extraction Time
One of the factors in making a good shot of espresso is extraction time. If you pull the shot for too short a time, only the bright and sour notes of the coffee will be extracted. Lengthening the extraction time gives the water more time to get into contact with the coffee grounds allowing more flavor compounds to be extracted. Of course, you can also over-extract a shot, but we’ll get to that in a second.
As a rule of thumb, an espresso that was pulled for less than 20 seconds will be sour. The sweet spot for extraction time is between 20 and 30 seconds.
Using a finer grind
If you use a finer grind, the resistance for the water will be greater and more oils will be extracted.
Tamping More Firmly
Not tamping your espresso well will lead to a sour espresso shot. The reason is that not tamping well leads to an inconsistent coffee bed that, in turn, leads to channeling. This is when the water just flows through one area which results in uneven extraction and a sour flavor in your espresso. You want an even water flow through the puck in order to get a more balanced flavor.
Using a Higher Water Temperature
The ideal temperature for water to brew coffee with is between 195°F and 204° (95,5°C and 96°C). If your brew is sour it might be that you are using too cold water. You can try to increase the water temperature and also to preheat the portafilter.
Adding More Coffee to the Basket
With espresso extraction, the coffee-to-water ratio is very important. This ratio is also referred to as the brew ratio. If you are using too much water in comparison to coffee, you will get a sour coffee taste.
Generally, baristas use a 1:2 (coffee to water) ratio for a shot of espresso. For this, you will use about 18-21g of coffee. However, the roast level and the kind of bean that you are using will have an impact on this. So, if you use a 1:2 ratio and the espresso turns out sour, you could try to add more coffee.
Change the Kind of Bean That You are Using
Light roast beans (also called blonde roast) tend to have a more bitter taste. If your espresso is sour, consider using a darker roast. (Here is a detailed comparison between blonde roast and normal espresso.)
Also, beans from Africa and Central America tend to be sourer. Furthermore, robusta beans are more bitter than Arabica beans, so you could also try that.
Wait a Few Days After Roasting Your Beans to Use it
After roasting your beans they first need to degas otherwise it will result in a sour brew. The reason for this is that carbon dioxide builds up in the beans when you are roasting them.
Dark roaster beans take about five days to degas. Lighter roasted beans, on the other hand, take about ten days. So, you have to be patient after roasting your beans.
Like a sour one, a bitter espresso shot is not particularly tasty either. Bitter espresso, as opposed to sour espresso, had a quite brown color. You can also see it in the puck, which, will be very wet. Most likely, you extracted the shot for too long.
The reason for this is that tannic acid that is one of the heavier compounds in coffee beans. This means that it needs a high temperature and pressure for extraction. When you extract the shot for too long, you give this compound time to be extracted.
However, apart from over-extraction, there are also other possible reasons for your expresso’s being bitter.
Here are some reasons why your espresso might be bitter:
- A too fine grind
- Too much coffee in the basket
- Too high water temperature
- Unclean Espresso Machine
- Old or Poor Quality Beans
- Using the Wrong Kind of Bean
How to Fix Espresso That Has a Bitter Taste?
Shorter Extraction Time
As I mentioned before over-extracting your shot will make it bitter. The ideal extraction time is between 20 and 30 seconds.
Use a Coarser Grind
A coarser grind will let the water pass faster through the grounds resulting in less time for the compounds to be extracted. This, in turn, leads to a less bitter and smoother espresso shot.
Use Less Coffee
Like when your espresso is sour, the ratio of coffee to water is quite important. A good starting point is a 1:2 coffee-to-water ratio. For this, the amount of ground coffee beans that you should be using is about 18-21g.
Use a Lower Water Temperature
If your espresso is bitter it could be that you are using a too hot temperature. You could try a lower temperature. As I mentioned with when your espresso is sour, the ideal temperature for water to brew coffee with is between 195°F and 204° (95,5°C and 96°C).
Clean Your Coffee Machine
Another possible reason for bitter coffee is an uncleaned machine. The coffee residue and oils that build up over time could result in a bitter shot of espresso. It is a good idea to use hot water to clean your coffee maker after each use. If the oils and residue are quite a lot by now, using vinegar to remove it can be quite helpful. Be sure to clean the group head and the portafilter.
Use Fresh, High-Quality Coffee Beans
Old coffee beans can be the culprit for bitter espresso. The same goes for overly roasted beans. Using fresh beans will help avoid a bitter brew. Old coffee could also be the reason for a burnt taste.
Change the Kind of Bean That You are Using
Using a too dark roast could result in a bitter shot of espresso. Thus, you could consider using a lighter roast. Another possibility is to reconsider the origin of the beans that you are using. Beans from Africa and Central America tend to be sourer, which, could be the solution to your problem. Furthermore, Robusta beans are a bit more bitter than Arabica beans. So, you could also try swapping your Arabica beans for Robusta ones.
Summary: Espresso Bitter vs Sour
This is probably the most common reason for coffee-making going wrong. Although you need fine coffee grounds to ensure a good cup of coffee, grinding too fine will result in a bitter espresso. A good rule of thumb, when it gets to grinding, is that the grounds should be about the size of a grain of salt.
The coffee grinder that you are using could also make a difference. A blade grinder will give you an inconsistent grind, which, is not ideal.
Type of Coffee
Another important factor is the kind of beans that you use. Generally, lighter roasts tend to be sourer, and darker roasts are on the more bitter side of the taste spectrum.
Also, consider the origin of your coffee. As I mentioned earlier, Arabica beans as well as beans from Africa and Central America will give you a sourer brew whereas Robusta beans tend to be more bitter.
Amount of Coffee
The amount of coffee that you use determines the coffee-to-water ratio. The ratio that is used most is 2:1 (coffee to water), however, there are multiple factors involved and you could try to adjust the ratio to your taste.
Generally, speaking using more water could solve sour-tasting coffee and more coffee can help reduce bitter flavors.
Higher temperatures could cause a bitter espresso brew and lower temperatures a sour one. The ideal temperature at which to pull the shot is between 195°F and 204° (95,5°C and 96°C). Also, always make sure that your machine is warmed up properly before you attempt the brewing process. Pulling a shot without coffee could help the warming-up process.
Make sure that you get a level and even puck. However, be sure to not pack it too firmly as this could also negatively influence the taste of your espresso.
Fixing Your Espresso
The first thing to check when your espresso tastes either burnt or sour is to adjust the grind size. If this doesn’t solve your problem, one-by-one go through the other options to see which could solve your problem. Just be sure to only change one thing at a time and remember what you did so you can know what worked and what didn’t.
The best way to find your perfect brew is to experiment. The definition of good espresso is a highly personal one and in the end, no one can give you the exact perfect recipe.
In life, the taste of your coffee is vital and that is why it is important to know how to fix bad-tasting coffee. This includes cold brew that is too bitter.
Like with espresso and all other coffee for that matter, you don’t want your cold brew to taste bad. Here is how you can make your cold brew less bitter.