Words to understand
Extraction = This refers to the pour of the coffee from your espresso machine. It’s extracting the coffee oils from the beans.
Blonding = When the coffee pour is a pale yellow colour
Basket = The basket holds the coffee grinds which the water flows through
Crema = The light brown oils that sit atop the coffee shot.
Puck = The coffee grinds that remain in your basket after you have run a shot. The make a shape like a hockey puck when you empty the basket out.
Let’s Get Started!
First, check that your beans aren’t too fresh or too old. Despite common belief that freshly roasted coffee beans are the best to use, for espresso, this actually might be the reason for your bad extraction. So, before you even start to adjust your machine, check that you’re using;
- beans that are at least 1-2 weeks old (possibly 3 weeks if you live in colder weather!)
- good, high-quality beans.
- medium roast coffee beans (light roasted beans generally have a sour taste when extracted for espresso, while dark roasted beans are often bitter in flavour)
Bitter coffee shot (left), Great coffee shot (right)
Identifying a bitter shot
There are some characteristics you can look for in your shot to tell that it’s sour without even needing to taste it. Look for a thin white/pale yellow watery pour and spirals/billowing at the end of the extraction. Big patches of white on your crema are also another sign as well as a long pour time. After the shot, a way to confirm is to look at the puck, and if it’s super soggy and sloppy, it’s not the shot you’re wanting.
How to fix it
A good pour will be somewhere between 25-35 seconds to get around 30ml from the extraction. Keep an eye on the shot as it comes through because you’ll want to turn it off as soon as you see the coffee change colour to a light ‘blonde’. The blonde that is you see is called blonding, and its almost pure caffeine which tastes very bitter, so it’s important to stop it when you see it.
One mistake that is often made is trying to extract too much coffee out of a single dose. If you want a strong coffee, get a bigger basket (22g-28g) and keep the shot time within the ideal range. You’ll still get your caffeine fix, but you won’t have to endure a bitter coffee!