Why Does My Espresso Taste Burnt?
Espresso is a favorite morning beverage across the globe.
Its rich and powerful flavors can be potent, but espresso should never taste burnt.
In espresso, burnt taste can be the result of a mistake in the brewing process or it could be something else entirely.
If your espresso tastes burnt, read on to figure out why and what you can do to make your espresso taste like the robust coffee it should be.
What Makes Espresso Taste Burnt?
Short Answer: Burnt tasting espresso comes from over-extracted coffee or burnt beans. The grind is too fine, the tamp is too hard, there’s too much coffee, or the beans are over roasted.
Let’s go over all the possible reasons your espresso tastes burnt in more detail below.
Over Roasted Coffee Beans
Burnt tasting coffee can be caused by several factors and it may not even be due to the brewing process.
Sometimes coffee will taste burnt even when it has been brewed correctly.
When this is the case, it is most likely due to low-quality coffee beans.
Low-quality coffee beans come with a host of problems but one of the biggest is over-roasted coffee beans.
If you are familiar with coffee, then you are already aware of their different roast levels.
The roast level of a batch of coffee can bring out varying flavors in the final brewed coffee.
Light roast tends to carry floral and citrus notes while dark roasts will have chocolate and caramel flavors.
Italian roast coffee beans are roasted longer than dark roast coffee beans which gives them a unique smokey flavor that is perfect for espresso.
However, there is a large distinction between the smoky flavor of an Italian roast and the burnt taste of low-quality coffee.
For one, burnt coffee beans will taste extraordinarily bitter.
Coffee, especially espresso, does have a bitter quality to it, but coffee brewed with burnt coffee beans has an overwhelming taste which makes it almost unpalatable.
Burnt coffee beans can often be spotted by the color of the coffee beans.
These low-quality coffee beans will have patches of darker color.
There will be an inconsistency in the color of these coffee beans.
Burnt coffee beans will look charred and blackened in comparison to the rest of the bag. They will have a dark, scorched appearance.
Burnt coffee beans are caused by inconsistency during the roasting process.
Oftentimes, a sudden spike in the roasting temperature will cause some of the coffee beans to burn, leaving others uncharred.
Coffee companies with low-quality control will bag the burnt coffee beans along with the well-roasted ones.
This can make them hard to pick out during purchasing.
The best way to avoid over roasted coffee beans is by purchasing quality coffee from a company that cares about the integrity of its products.
Trade Coffee is a good place to order fresh, high-quality coffee from a curated list of roasters.
High Brewing Temperature
If your coffee beans are high quality, burnt-tasting coffee might be a result of the temperature of the brewing water.
Similar to how exposing coffee beans to high temperatures during the roasting process chars them, exposing ground coffee to boiling water will continue to roast the coffee beans.
This leaves an unpleasant burnt taste in the coffee.
The rate at which flavor is extracted from coffee grounds is directly related to how hot the brewing water is.
If the water is below a certain temperature, then it will not be able to pull enough oils from the coffee beans to flavor the coffee.
This is called under extraction.
Under extracted coffee leaves much to be desired in terms of flavor.
Water that is too hot but not boiling will over-extract the coffee.
Coffee grounds exposed to water that is too hot will release a lot of oils.
These oils will flavor the coffee, but too many will make the coffee taste bitter.
Coffee made with water that is still boiling will burn the grounds without extracting any of the flavors we love.
Instead of over-extracting the oils from the coffee grounds, boiling water destroys the fragile flavors of the coffee grounds.
The result is a weak and burnt-tasting coffee.
To avoid this problem, it is important to pay attention to the temperature of your brewing water.
This is easy to do with manual brewing methods like a French press or a pour-over but can be harder to do with espresso.
Many espresso machines can be pre-programmed to brew espresso at a certain temperature.
If the espresso is still tasting burnt, it is a good idea to descale your espresso machine.
Descaling is the process of removing mineral buildup that occurs when water is repeatedly heated in an enclosed space like an espresso machine.
This buildup of minerals can interfere with the espresso machine’s temperature sensors.
By descaling your espresso machine, you will be able to measure the temperature of the brewing water more accurately, which will help you avoid burnt-tasting espresso.
Reheating Coffee
One of the easiest ways to achieve a burnt coffee flavor is by reheating old coffee.
This is because coffee is already fully brewed.
By reheating brewed coffee, it continues to brew, which will inevitably give it a burnt taste.
This can be better understood through the analogy of a freshly baked batch of cookies.
Let’s say that after these cookies were completely baked that they were placed on a plate to cool off.
Once cooled off, these fully baked cookies can’t be warmed back up in the oven because that would continue to cook them.
They would eventually burn.
The same thing happens when coffee is reheated.
Coffee that is kept piping hot will also taste burnt after a while.
This is because by keeping coffee at the same temperature it was brewed at, the coffee will continue to brew which will cause a burnt taste.
We can use the cookie analogy to explain this as well.
Imagine that freshly baked cookies have been taken out of the oven but are not removed from the hot pan they were baked on.
The cookies will continue to cook even when they have been taken out of the oven because of the heat from the pan.
Carafes that continuously heat brewed coffee to keep it warm will run into this problem.
Coffee that has been allowed to cool and then reheated in a microwave will taste burnt because the second wave of heat they are exposed to allows the coffee to release quintic and caffeic acids.
These molecules are what we attribute bitter and burnt flavors in coffee to.
The only way around it is to insulate the brewed coffee to keep it warm or to brew a fresh batch.
In recent years, companies have developed smart mugs, such as The Ember, to keep coffee at optimal drinking temperatures without burning or reheating.
Friction from Coffee Grinders
Coffee grinders will often generate heat that cooks the coffee beans.
Too much exposure to this heat can result in a burnt-tasting coffee.
The friction caused by the blades and burrs of a coffee grinder can often create enough heat to cook already roasted coffee beans, therefore ruining their flavor.
Some coffee grinders are better than others, however.
For example, blade grinders will create more friction than burr grinders.
Very fast grinders will also create more friction than a slower coffee grinder.
The best way to ensure a coffee grinder is not cooking the coffee beans is by pulsing the coffee instead of grinding continuously.
This gives the heat caused by the friction a chance to dissipate before more heat is created.
To minimize this friction while producing fine, uniform ground coffee for espresso, it may be best to use a conical burr grinder such as the Baratza Sette, or Niche Zero.
Over-Extraction
All the reasons mentioned above can result in a burnt taste in any coffee, not just espresso.
Over roasted coffee beans, a high brewing temperature, reheated coffee, and friction from a coffee grinder can all cause coffee to taste burnt.
For espresso specifically, burnt tasting coffee could be a result of over-extraction.
It is very easy to over-extract espresso because of its temperamental brewing method.
Espresso requires precision and in-depth knowledge of how coffee is brewed, which makes it one of the most challenging brewing methods.
Over-extracted espresso will taste burnt and it is one of the easiest brewing mistakes to make.
Over-extracted espresso can be made in one of two ways.
It can be achieved by exposing too many of the coffee bean’s oils to the water.
This happens when the grind is too fine, leaving a lot of surface area of the coffee grounds for the water to interact with.
Over extraction can also occur if the water is exposed to the coffee grounds for too long.
The flavors of the coffee grounds will continuously soak into the water until they become over-saturated.
This will make them taste bitter and oftentimes burnt if the over-extraction is bad enough.
By paying close attention to the grind size and the brew time, burnt-tasting espresso can be easily avoided.
Espresso is ground very fine.
It is often compared to the consistency of table salt.
The average espresso shot will take approximately 25 seconds to brew, but this time can vary depending on the coffee, the espresso machine, or the filter basket size.
The best way to discover what is causing espresso to taste burnt is with trial and error.
By experimenting with better coffee beans, the water temperature, the brew time, and the grind size, anyone can discover how to brew quality espresso.
Conclusion
Good espresso can tend to have a robust flavor, and depending on the beans, somewhat of a bitter aftertaste.
When brewed using Italian roast coffee beans, espresso will take on a smoky, slightly charred flavor.
Darker espresso has rich notes of chocolate and caramel but should never taste burnt.
Burnt-tasting espresso is a good indication that something is wrong.
With fresh, good quality, specialty coffee beans, the burnt taste can be fixed through trial and error using the causes outlined above.
If the espresso is still burnt or is too dark for your taste, try brewing again with a different, more familiar coffee and see if you get closer to the expected result.
