Coffee brewing: Extraction.


A note about Extraction

When you mix coffee and water, a lot of things happen. The most relevant and easy to understand of all these things is that water dissolves a lot of coffee's flavours. These dissolved flavours make up (almost) everything you taste when you drink a cup of coffee.

On the journey from the farm to your cup, a lot of steps are involved and a lot of hard work is done to create the perfect bean. As you brew your coffee, all the potential locked within the coffee bean can be lost by bad brewing. 

Strength. an often misused and misunderstood term. Strength of coffee has to do with water to grounds ratio. The more grounds and the less water are used for brewing, the stronger your coffee gets. Coffee strength preferences are very personal. We often get asked for our strongest coffee, by which often is meant, our darkest roast. note that coffee strength and roast type are two very different things! 

 

Making a good cup of coffee is all about proper extraction. Extraction is determined by several factors, but the main three to worry about are grind sizewater temperature, and immersion time.The coarser the grind, the quicker water will flow through the coffee. As of such, less extraction will take place, creating more acidic coffee. Similarly, the smaller the grind size, the less gaps for water to flow through and so the longer extraction will take. This will result in a more bitter brew..  For this reason, grind consistency is crucial. If your grinds are different sizes, some of them will be extracted more than others – meaning it’ll be nearly impossible to get the profile you want.

Turbulence is how much the coffee/water moves and therefore interacts. When brewing pour the water in concentric circles to ensure the most even extraction possible. Some people give their coffee a stir after pouring to ensure all the grinds are exposed to the water. Others pay close attention to the rate of their pour so as to not disturb the grounds while adding water.

Remember, the general rule: the shorter the extraction time, the fruitier and more acidic the coffee becomes. Too short, and it will turn sour. The longer the extraction time, the more body the coffee develops, until it becomes bitter. 

Brewing ratio recommendations: though grounds/water ratios change depending on your brewing method, the general rule is 30 grams of coffee grinds for 500ml. Note that the general coffee spoon contains 7grams when level. We'll discuss brewing methods and grinds in our next post.

Note: If you want to be sure of your grammage and/or consistent in your grammage, you can always use a kitchen scale to measure your coffee grounds. 

 

Stay tuned for our next post about grinds!

 

sources: perfectdailygrind, world atlas of coffee

 


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