How to correctly extract coffee when brewing
Extracting coffee correctly for optimum flavour is one of the biggest challenges when brewing speciality coffee. Several factors affect how good your cup of coffee will taste and these include three key factors:
- Quality of the green coffee
- Roasting style
- Brew method
- How well the coffee has been extracted
This blog post is all about how to extract coffee correctly when brewing to maximise flavour potential and will help you get the best from the coffee you buy!
As a speciality coffee roastery owner and licensed Q grader, I focus on making sure Horsham Coffee Roaster only buy speciality grade coffee, and cup scores tend to range from 83 to 90. We then make sure to focus on roasting these coffees to maximise their potential using our Loring S35 with a focus on consistent, repeatable roasts with regular cupping and evaluation. Once we are certain the coffee is roasted and tasting as it should, the final results are in the hands of a barista or customer brewing coffee at home. Unfortunately, there are many areas where this can go wrong, and one of these is flavour extraction.
How to extract coffee correctly
One key factor in making sure you extract coffee correctly is to make sure that you use a brew method that will allow you to evenly infused all of the ground coffee. When we talk about coffee brewing, we tend to refer to immersion and filter brewing or espresso brewing. So I'm going to discuss these as two categories.
Espresso extraction:
Exacting espresso correctly can be very challenging due to the high pressure involved when brewing espresso coffee. One of the biggest challenges is to ensure that water flows evenly through the bed of coffee. If the grind, tamp or distribution are not correct, the coffee will not extract evenly and will be prone to channelling through sections of the 'puck' of coffee. This will cause one area to over-extract, potentially increasing bitterness and reducing sweetness.
So, how do you avoid incorrect extraction? The best way to ensure you extract espresso coffee correctly is to use a bottomless portafilter like the one in the image below:
If you have incorrectly distributed the coffee, then the water will not gather together in a steady stream and will tend to spit or come out through one particular side of the basket. This will mean that you did not extract coffee correctly across the entire bed resulting in poor flavours.
Even distribution is not the only factor as contact time makes a big difference too. If you'd like to learn more about espresso brewing, please look at our espresso brew guide and video.
Filter and immersion coffee brew extraction:
To extract coffee correctly when brewing filter coffee, Aeropress or cafetiere, it's essential to make sure you perfectly saturate all of the coffee and use a set brew method that considers the dose weight of the coffee, water weight and the contact time.
Brewing coffee using a cafetiere is one of the easiest and most popular methods. Unfortunately, many people don't stick to a set method, which can result in under or over-extracted coffee that either tastes weak or bitter. Generally, people will blame the coffee without realising that the issue really lies with the correct extraction.
One of the tools that we regularly use at the roastery to measure extraction is a refractometer. This allows us to measure the total dissolved solids in the brewed coffee. You can read more about TDS and on the Barista Institute website. Generally speaking, with brewed coffee, we aim for a TDS% of around 1.3. So, for example, an Aeropress brewed with 14 grams of coffee and 210 grams of water would yield about 1.3% TDS.
Using a refractometer is a great way for us to check the solubility of coffee but it isn't something most people would have at home to check that their coffee extract percentage is correct!
Generally, we have to use our taste buds to do this, but my advice once again is to make sure you follow a set recipe, and if you are brewing cafetiere, Aeropress or filter is to make sure that all the coffee grounds have been properly soaked with water. One of the most common issue we see if that novice brewed will pour a filter and not ensure that the water pours evenly and the entire bed of coffee has been properly saturated!
If you are keen to extract coffee with better flavours at a higher percentage, then head over to our brew guides on the following methods:
