Popular articles
Recent discussions on forum
How to Measure Extraction Coffee
About coffee extraction, what affects it, and how to measure it.
Published February 2, 2022
Select language
Daniel Hedlund
Coffee experts@The Coffee Lab
If you want to make a better cup of coffee, the good news is that it might be easier than you think. When you understand coffee extraction, how to measure it and how it works, it becomes easier to control several different factors including the balance, sweetness, and acidity to get a perfect cup every time.
Coffee extraction refers to the method by which flavors, aromas, and other compounds are dissolved from roasted and ground coffee beans. When the coffee grounds are brewed in water, hundreds of unique compounds are extracted from the coffee grounds, making your daily cup of coffee. These compounds directly impact the aroma and flavor of your cup of coffee.
Typically, extracted coffee contains various water-soluble compounds including caffeine, sugars, acids, lipids, and carbohydrates. If you want more control over the profile of your cup of coffee, it’s important to control how these compounds are extracted from the grounds.
How Coffee Extraction Affects Taste
The compounds in the coffee grounds are not all extracted at the same time. Acids are extracted first, giving the coffee a fruity and acidic taste, followed by sweetness, adding balance, and then finally, the compounds that add bitterness to the coffee are extracted.
If coffee is under-extracted, it will not have the slight bitterness and sweetness that is needed to balance the cup, and as a result, it usually tastes quite sour. On the other hand, a brew that has been over-extracted is usually quite bitter, as the compounds that add acidity and sweetness to the cup are overwhelmed. Controlling the extraction allows you to create coffee that is more balanced to your taste.
The Perfect Extraction Level
If you’re getting into making coffee at home, you may have heard about extraction percentages and the ideal extraction level of Total Dissolved Solids. This simply refers to how many compounds have been extracted into the water from the coffee and is usually between 18-22%.
However, when determining the perfect level to extract coffee beans compounds, it is important to bear in mind that different coffees have different characteristics. So, instead of aiming for a certain number, it’s always better to focus on achieving the highest percentage extraction at which the specific coffee you are drinking is going to taste best.
Controlling Coffee Extraction
When it comes to getting the best flavors from your coffee, getting the right level of extraction is one of the most important factors to consider. When you understand how this happens, you will be better able to figure out what has gone wrong if your coffee doesn’t taste right when you drink it. For example, if you’re tasting more acid than other compounds and your coffee has a sour taste to it, it could be over-extracted. To fix this, you might try using a finer grind or brewing more slowly. On the other hand, if your cup tastes too bitter, over extracted coffee might be the culprit. You may be able to fix this by using a larger grind to slow down the extraction time or brewing the coffee for less time.
When making coffee, it’s also important to avoid inconsistent extraction. This happens when some grounds are extracted faster than others, which leads to a combination of both under- and over-extracted coffee grounds. This results in problems, making it impossible to control your final flavor profile. To avoid this happening, it’s a good idea to invest in a high-quality burr grinder. Most of the time, inconsistent extraction happens when the coffee is ground using a blade grinder. While these are affordable and easy to get your hands on, they are not always the best choice since their design makes it impossible to get a consistent grind or control your grind level in as much detail.
Extraction can also be tweaked in order to compensate for factors with the coffee that are not ideal. For example, if you are using up old coffee beans that have gone a little stale, using a finer grind can help you achieve a better tasting coffee as this will allow for faster extraction, resulting in better notes from different compounds.
It’s also important to consider the roast level when thinking about extraction. If you’re using a dark roast, for example, these beans will typically be more soluble in comparison to medium and light roasts as they have been exposed to high heats for longer. As a result, they will usually extract faster in comparison to lighter roasted beans, which means that a coarser grind will usually work better.
Which Variables Influence Extraction?
Extraction and solubility can be impacted by a lot of factors, including some that are not in our control such as the unique genetic characteristics of the coffee. However, many of the factors that impact extraction are something that we can adjust.
The grind size is one important factor that will have an effect on how the coffee is extracted. Extraction will usually be much faster when using finely ground coffee compared to coarser grinds, as more surface area is exposed. Depending on the type of brewing method that you are using, this can sometimes lead to a higher risk of bitterness if the compounds extract too quickly. On the other hand, a coarse grind size can sometimes lead to more acidity due to the higher risk of under-extraction depending on the brewing method, which can lead to a flat, weak cup of coffee with fewer flavorful compounds extracted.
The grind size has an effect on the compactness of the coffee puck, creating either more or less room for the water to flow through the grounds, which can increase or decrease brewing times for filter or pour over coffee. Fine grounds are also more easily displaced by water, which is why it is important to make sure that they do not sit unsoaked rather than being saturated.
Another factor to consider when it comes to extraction is the brew time. The longer the coffee brews for, the more it will extract. In general, short brews will be more acidic, while longer ones have a more bitter taste. Espresso, for example, has a short brew time and uses a high amount of pressure to force water through a coffee puck that has been densely packed. Because of this, it is best made with a finer grind size to allow the water to flow easily and ensure that enough surface area for extraction is created. On the other hand, immersion brewing methods like French Press are longer brews, so a coarse grind is usually recommended to slow down the extraction and avoid a bitter-tasting coffee.
How Water Affects Extraction
The temperature and quality of the water that you use for brewing coffee will also have an impact on the extraction. The ideal water temperature for making coffee is around 195-205 degrees Fahrenheit, which is just under boiling, and at a point where most of the flavor compounds will be able to easily dissolve in the water. Extraction will be faster with hotter water, while on the other hand, cooler water will slow the extraction down. For example, cold brew coffee which is extracted in cold water will take at least twelve hours to brew and fully extract all the desired compounds. At some point, certain compounds will not extract if the water is too cool, which is why cold brew often has a more mellow flavor compared to hot brews.
The quality of the water is another factor to consider. According to the Specialty Coffee Association, any water that you use for brewing coffee should be free from any contaminants that could impact the flavor and pH neutral. Hard water does contain minerals that can sometimes help with the extraction process. For example, magnesium in water can help with the extraction of sharper, fruity notes, while calcium in the water can enhance the creamy note in the coffee. However, too many minerals in the water can have the opposite effect, impacting the flavor of the coffee by reducing the amount of extraction. If you are not sure, it’s a good idea to make coffee with filtered or bottled water.
What is Coffee Extract?
Now that you know about extraction, what is coffee extract vs coffee? How to extract caffeine from instant coffee? Coffee extract occurs when you combine roasted coffee beans with alcohol and is a more concentrated version of coffee made using a different method of extracting the flavors. All you need to do is crush some coffee beans, mix them with alcohol, and allow the mixture to sit until you achieve the desired flavor. The alcohol is key since it acts as a solvent that extracts the trapped solids. Choose a mild-tasting type of alcohol like vodka that will not affect the flavor or overwhelm the coffee taste.
Extraction is an important factor to consider when making coffee at home or making coffee extract for use in baking. Extraction refers to the process of dissolving the flavor and aroma compounds in coffee with water or alcohol.
About the author
Daniel Hedlund
Working with the Era of We initiative and loves knowledge sharing and a really good cup of coffee.
Add comment
More on the coffee lab
Sign up and contribute now