Have you ever faced challenges in preparing coffee with the same beans, tools, and method, but the results vary between excessive acidity or extreme bitterness?
In the business and cafe world, this issue often doesn't stem from the quality of the beans, but rather from the coffee extraction process.
In this article from Marid, we will provide a specialized explanation distinguishing between under-extraction and over-extraction, the factors influencing it, and how staff or cafe managers can precisely identify the source of the problem by analyzing the cup's taste, thus contributing to improving the final product's quality and increasing customer satisfaction.
Table of Contents
What does coffee extraction mean?
Coffee extraction is the process of dissolving soluble compounds from coffee beans using water, where factors such as temperature, grind size, and brewing time affect the final flavor quality of the coffee.
In the world of cafes, a precise understanding of the extraction process enables the team to enhance the customer experience by offering coffee with a balanced and distinct flavor, thereby boosting the brand's reputation and increasing customer satisfaction.
Ideal extraction achieves a balance between acidity, sweetness, and bitterness in the cup, and relies on precise control over influencing factors such as water temperature, coffee bean type, and brewing methods used.
What factors influence coffee extraction?
The quality of coffee extraction is influenced by several key factors that must be well understood to achieve the best flavor and balance in the cup. Below are the most important factors that directly affect the coffee extraction process:
1. Roasting
The roasting level of coffee beans plays an important role in determining the speed and depth of extraction. Lightly roasted coffee beans require a longer time or finer grind to extract flavors in a balanced way, while dark roasted beans require a shorter time and coarser grind. Therefore, the appropriate roast level should be chosen according to the brewing method to achieve the best extraction.
2. Grinding
The grind level of coffee beans is one of the most influential factors in coffee extraction. A coarse grind leads to under-extraction, making the coffee acidic and weak, while a fine grind speeds up extraction and can lead to over-extraction with a bitter and heavy taste. Therefore, the grind size must be precisely adjusted according to the brewing method and the desired extraction time.
3. Time
The coffee brewing time significantly affects the quality of extraction. A short extraction period leads to an acidic and weak taste due to under-extraction, while a long extraction period causes a bitter and heavy taste due to over-extraction. Therefore, the brewing time must be controlled to achieve a balance between acidity and bitterness in the cup.
Types of Extraction:
Under-extraction
Under-extraction occurs when coffee does not get enough time or suitable conditions to fully extract essential compounds and flavors.
Sensory characteristics of coffee taste in this case:
Distinct and excessive acidity
- Light and watery body
- A taste that disappears quickly after tasting
Common causes of under-extraction:
Grinding beans too coarsely
- Too short brewing time
- Water flowing too quickly through the coffee
- Using lightly roasted beans with an unsuitable brewing recipe
Scientific explanation of what happens:
In this case, acids and easily soluble compounds are extracted first, leading to a prominent acidity in the taste, while sugars and compounds responsible for sweetness and full flavor depth are not extracted. This results in an unbalanced cup of coffee lacking the moderate sweetness and bitterness that create a distinctive flavor balance.
Over-extraction
Over-extraction occurs when too many compounds are extracted during the coffee extraction process, due to unbalanced brewing conditions that affect the final flavor quality.
Sensory characteristics of coffee taste in this case:
Bitter and strong taste
Dry sensation in the mouth
Undesirable flavors such as burnt or woody taste
