Why is my coffee bitter?!

Posted by NB Coffee Roasters on

The phrase that send quivers in to every hipster baristas' man bun
"my coffee is bitter"
But is it really?
Bitterness is that harsh, dry, back of the throat, last taste before you swallow nastiness, often associated with burnt over cooked coffee.  But often vegetal, undercooked coffee acid flavours can impart similar traits towards the front of the mouth.
It tastes bad doesn't it? Why does it matter where it tastes bad in my mouth?
Well I'll tell ya! Read on!
Consumers often blame bitterness on the roasted beans and hence the roaster, but in reality, bitterness is more a result of the way the coffee soluble matter has been extracted from the ground coffee.
Matt Perger form Barista Hustle writes a great article on coffee solubles.  Let me summarise.  A roasted coffee bean contains soluble matter which we extract by soaking the coffee grounds in hot water.  Not all solubles taste great though, and too much time, or too little time will create unpleasant flavours.
How do you fix it?
Lets assume the person who roasts your coffee is a good roaster.  They know how to cook the inside of the bean (not just the outside), the beans are fresh (under a month old at most), and when you drink your coffee you dont taste char and smoke.  Lets also assume you clean your equipment regularly and that your grinder blades (if you have a grinder) arent dull.
Reason 1: Brew time
Espresso extraction
If you use a little amount of water in your brew method (espresso machine, espresso shot) the water will be in contact with the coffee for a short time (say 30 secs).  
Tasting horrible, back of mouth bitterness?  This could be too much coffee and/or too finely ground coffee resulting in the water being in contact with the coffee for too long.  The effect is the bad soluble matter being extracted, and the good soluble matter being damaged by excessively long exposure to the hot water.
Answer: try less coffee at a coarser grind.  Find a dose amount which when tamped, doesn't hit the shower screen in your espresso machine.  Keep your dose consistent, and change you grind until you are getting around 30-35 secs for a full double espresso shot extraction.
Taste and adjust accordingly.  Still bitter, make your grind coarser until you get an extraction time closer to 30 seconds.
Medium to slightly darker roasts work better with fast extraction methods.  Darker coffee has softer acids and more body, ideal for quicker extraction methods
Filter/French Press
If you use a lot of water in your brew method (say filter, pour over, french press) the coffee will be in contact with the water for longer, around 3-4 mins
Bitter coffee?
Answer - Lighter coffees work better with pour over/immersion brew methods, as the bean structure has not been weakened as much in the roast process.  This allows for longer brew times without the risk of severe over extraction of bitter compounds as well as the main reason - delicate, interesting acids are preserved meaning better flavour!

Reason 2: Bad coffee
Coffee roasting seems easy in theory and it sort of is, if you can control your roasting machine to do what you want it to.  A good roaster needs to cook the outside of the bean as closely as possible to the inside of the bean, without introducing flavours like smoke and char to the coffee, and without baking and dulling the unique taste of the coffee.
Easy right?!
While everyone's tastes are different, its hard not to argue that a naturally smooth, sweet, balanced coffee which leaves you wanting more, is the holy grail.
For espresso coffee, try medium roasted coffee, without excessive oiliness.  Supermarket coffee just wont do here, its too old and often over roasted in big batches with mismatched beans.
For other brew methods, try lighter single origin coffees.  Ask your roaster for filter roasts.  Single origins are highlighted in lighter roasts  and filter brew methods.  You may just discover something super delicious!
Too sour or weird tasting?  Chances are the coffee is underdeveloped (not cooked in the middle).  Tell your roaster they are fired, and come over to us!

Reason 3: Dirty Equipment
Clean your stuff! 
Coffee is amazing sticky and persistent.  Those delicious oils we love in our coffee, also stick to our equipment, building up quickly and becoming rancid, leaving undesirable flavours in its wake.  Imagine cooking dinner on the same unwashed pan for weeks.  Ok, too dramatic, but you get the picture

At Neutral Bay Coffee Roasters we love what we do.  Coffee doesn't have to be complicated, but it should taste good.  See you in store or online soon!