COFFEE EXTRACTION PROCESS- HERE’S WHAT YOU NEED TO KNOW
Are you looking for a way to improve your morning cup? Well, it's easier than you think. When you understand how coffee extraction works, you can control the sweetness, acidity, and balance in your brew.
As you read on, you'd better understand how coffee extraction works and how to improve on it.
WHAT IS COFFEE EXTRACTION?
Coffee extraction is the method by which we dissolve soluble oils, flavors, and other compounds from ground coffee. In other words, when coffee is brewed, unique compounds are extracted from the ground coffee into the water, making your morning cup.
The flavorful compounds that are extracted have a direct impact on the aroma of the coffee. Extracted coffee contains the following soluble compounds- Acids (some of which create sweet/sour flavors), Caffeine, lipids, Sugars (sweetness, viscosity), and Carbohydrates.
By controlling how these compounds are extracted, you can have more control of the profile of your cup.
DOES THE EXTRACTION METHOD AFFECT TASTE?
Not all coffee compounds are extracted at the same rate. The acids and fats are extracted first, then the sugar. Under extracted coffee won't have sweetness and slight bitterness that creates balance. It will have a sour taste.
Over extracted coffee will taste bitter because the compounds that create sweetness and acidity will be overwhelmed. If you’re having issues getting the perfect shot, you’ll figure it out as you dive deeper with our guide. You can create coffee that is balanced by controlling the extraction process.
Let’s break it down.
To make any coffee drink, you’ll use ground coffee and water. But why water? Water is a universal solvent. Water, on a molecular level, has a polar arrangement- two hydrogen atoms with a positive electrical charge and one oxygen atom with a negative charge on the other side.
This makes it hold in a wide variety of molecules, causing them to dissolve properly in the water. It will pull apart the bonds of other molecules, making them dissolve into the water. Once you heat the water, all the molecules will begin to move around quickly, making it a more efficient solvent.
Okay, we’ll take you one step back. Coffee beans are just roasted seeds from ‘coffee cherry’. The coffee seeds are full of stored energy like- complex sugars, acids, and even fat. Since it is a part of a fruit-bearing plant, the seed usually contains microscopic plant fibers.
These seeds are then transformed into something we can use to brew. It is then roasted. The heat from roasting does some important things to the components of the coffee seed. This is how it works- The heat evaporates any moisture found in the coffee.
The moisture then continues to leave the seed, the plant fibers in the coffee will become hard and dry. If it is roasted for too long, the plant fibers will continue to break down. So, most of the oils in the coffee will move to the surface and begin to oxidize. The next yhing is that the heat will begin to reduce the complex sugars into simple sugars, so it is easier to taste. As the roasting continues, some of this sugar will begin to caramelize and create a nutty aroma.
If the coffee is roasted for too long, these sugars will carbonize and the flavor will change from sweet and complex to smoky and burnt.
As the coffee is being roasted, many acids in the coffee will break down. If the roasting process is stopped too early, the acids in the coffee will be much. If the coffee is roasted too long, the acids will break down fully and taste bland.
At Coffee hero, we make sure the roast is perfect and never burnt and smoky. We aim to balance the levels of acidity so that your brew will neither be sour or bland.
Now you’ve got good coffee and water, all you have to do is start brewing. There is a general principle for all types of brewing methods - pour-over, espresso, drip, or French press. Take roasted coffee beans, grind them into fine or coarse particles and add water.
Once water is added to the grounds, it starts to extract all the flavorful compounds. Regardless of the brew method being used, water extracts flavorful compounds in the following order- fats and acids, sugar, then the plant fibers.
Acids and Fats: As we mentioned, these are the first compounds to be extracted. Acids contribute sour flavors, and they are the simplest compounds (molecularly speaking), this means that water will easily dissolve them into the brew. Then the oils or fats in coffee which are the body, are not simple. They are described as ‘hydrophobic’ and easily wash out of ground coffee.
Note: Many of the lighter aromas, fruity and floral are extracted at this point.
Sugars: The sugars are next. Simple sugars are even more molecularly complex than acids. You didn't see that coming right? Because of this, water needs more time to fully dissolve.
Plant fibers: Next, the sugars will begin to break down the plant fibers that hold the ground coffee together.
UNDERSTANDING BREW STRENGTH
Brewed coffee isn't just defined by the quality of its extraction, the strength of the drink is equally important. The strength here doesn't mean caffeine content. The strength here relates to the number of dissolved compounds in the beverage. Filter coffee contains roughly 1-2% dissolved coffee compounds, the remaining is about 98-99% water.
For espresso, it's a much-concentrated drink, it's made of 7-12% dissolved compounds and about 88-93% water. It is important to note that the strength of the coffee is largely the result of ground coffee to water ratio.
As we pointed out, if too little water is used, the coffee will be too concentrated and overpowering. If too much water is used, the coffee will feel watery. You need to understand that strength has a very strong relationship to extraction.
That is why we recommend finding a ratio that produces the strength of coffee you enjoy before working on the extraction. The brew method will also impact the way your coffee tastes, which means you have to consider your brewing equipment as well. The strength of your coffee also determines how it will taste for distinct flavors.
This means, the stronger the drink is, the more difficult it will be to parse out individual flavors. For instance, think about the difference between an iced tea and a milkshake. Iced tea will have more aroma and can be expressive while milkshakes are intense, sweet, and simple.
If you are taking espresso drinks with lots of milk, it is usually a good idea to have a stronger shot of espresso that cuts through the milk. You can try making a ristretto, or a restricted shot for lattes or cappuccinos.
These shots use a 1:1 or 1:1.5 ratio- this means 1 g ground coffee for every 1.5g of espresso. If you want a really clear distinct shot of espresso or you want to make an americano, you’ll have to use a larger ratio. We recommend a 1:2 ratio, 1g coffee to every 2g espresso.
When you’ve got a target ratio, it's time to adjust your grind to get the ideal extraction. If your coffee tastes sour, you’ll have to extract more out of the coffee. The easiest way to change this is to adjust your grind setting finer and ensure that your tamp is leveled. Read our full guide on how to tamp espresso like a pro.
The finer grind will have two effects- The smaller particles will slow the flow of the water through the coffee, which makes it pull out more sweetness and the small particles will have more surface area exposed, making it easier for water to enter the coffee grounds. If your shots taste too bitter and bland, you’ll have to extract less from the coffee.
The easiest way to do this is to adjust your grind setting but this time, you’ll make it coarser. Let's give you more techniques.
There's something coffee experts call brew manipulation, you should apply it.
What Is Brew Manipulation?
This is the process of altering the taste of your coffee and changing the way its brewed. There are different ways to improve your coffee experience.
Bypassing: This is simply adding water to already brewed coffee and helps dilute your coffee. If you prefer the strong-flavored coffee that's not so keen on the viscous mouthful, just add extra water to reduce the brew strength.
Pre infusing: This is the process of pouring enough water to saturate your grounds and is normally used during infusion brewing. Pre-infusing helps to improve the overall quality of the extraction, especially for drip-brew.
Agitation: Agitation involves the stirring of the coffee grounds during the brewing process to increase the rate of extraction and is useful for steeping methods. This helps to break up the crust and build up wet grounds that float to the surface. There you have it!
Now you understand how coffee extraction works, you can brew the perfect cup of coffee- And you know the best way to start is to get freshly roasted coffee beans from us. Click here to get some.