At least 3 weeks
Around 100 ppm
When brewing espresso in our shops, we have a rather simple approach. Having coffee rested for at least 3 weeks, clean water at a hardness of around 100 ppm, and a machine set to 95°C and 9 bar of pressure will help you to create balanced extractions of our omni-roasted coffees. When roasted in this way, our coffees also have a very long shelf life. We often continue to experiment with coffees and discover more of their potential beyond 3 months from roast. We recommend a ratio of just over 2:1, our standard recipe uses 17g (0.6oz) of dry coffee to 38g (1.34oz) of espresso in the cup. We’d like the extraction to take place in over 30 seconds and often up to around 35, but this can vary depending on many factors, including your grinder and the make up of your brewing water. Taste with a critical palate and make adjustments to your brewing.
To brew coffee well, extraction is an important concept to understand. If we were able to dry out coffee grounds after they have been brewed, they will have lost about 20% of their weight. This is the amount that we have dissolved into our cup during brewing, and the percentage is termed extraction. This is important, as flavour does not extract from coffee in a linear way, more is not necessarily more. When we begin to brew a coffee, the natural acids present in the coffee will extract most easily, followed by sugars, and then heavier bitter compounds towards the end of the brew. This means controlling how much we extract from a coffee will control the balance of flavour in your cup. Extract too little, and we have a sour coffee, too much acid from the beginning of the brew, and not enough sweetness to create balance. Extract too much, and we will extract too much bitterness from later in the brew, resulting in an overall bitter and drying cup.
There are two main ways we can control extraction, in ANY method of brewing coffee. Grind Size, and Contact Time. The table below shows a guide to controlling extraction when brewing.
|Coffee Tastes||Grind Size||Contact Time|
By tweaking these variables, and tasting every cup you brew with a critical pallet, you’re sure to be brewing transparent and delicious brews.