This last technical summer series is dedicated to understanding coffee brewing in more depth. This will enable you to find your own “perfect brew” and more easily adapt to any potential new brewing method, or new bean (yes, we’re working on another limited edition Honey micro-lot coming your way in September 😉).
We define brewing or “coffee extraction”, as the process of transferring aromas, flavors, and textural components from the coffee grounds into your brewed cup of coffee. Your freshly roasted coffee grounds will always contain two types of compounds: soluble (typically desirable) and insoluble (typically less desirable).
Soluble compounds include both soluble aromas (in gas form) and soluble flavors (in liquid form). Since soluble aromas are not -strictly speaking- “dissolved” in water, they are lost over time, as your cup of coffee cools down- which is one of the primary reasons your coffee tastes a little different as it cools! Yet, all soluble flavors and textural components will remain unchanged as your coffee cools down, which is also why professionals typically judge both flavor and textural attributes of a particular coffee only after the brew has had a chance to cool down.
Insoluble compounds include oils (which are non-polar, so they won’t dissolve in water, and will float on your cup’s surface, due to their lower density), and fines (which are more noticeable when you are not brewing using a paper filter, i.e. on French Press or any method using a metal filter). Fines are simply very small grinds that are inevitably produced by your grinder (even the best ones!), as some particles get further degraded by the heat and movement of the burrs produced during grinding. The presence of both oils and some fines - or insoluble solids - tends to make your cup more viscous, or “full bodied”, yet excess fines may make your coffee feel gritty. If you find that fines and oils are something you don’t particularly enjoy, using a paper filter will largely eliminate both. In general, the thicker your filter, the less fines and oils you can expect in your final brew (yet, you should keep in mind you'll also be sacrificing some of your cup’s texture or “body”).
Hope you enjoyed this little coffee chemistry lesson… and that it helps you continue Brewing Greatness in the world with us! Always grateful for you,
Jolian & Lisbeth
P.S. We’ll be roasting Mondays and Thursdays for the next two weeks, since the Lakeland farmer’s market is closed in August and it is the only month of the year that we can offer our amazing small team some (very well deserved) weekends off! We’ll be back to our Mon/Weds/Fri roasts the week of Aug 27. Thank you for helping us make our Ethos a reality every single day… we LOVE roasting for you!
