I’ll be honest — making espresso isn’t the easiest affair. A few seconds or grams in the wrong direction can mean the difference between something enjoyable, or something destined for the drain.
For espresso that’s too bitter, the usual culprit is a shot pulling too slowly caused by grinds that are too fine. Read on for tips on how to tackle these flaws in extraction, as well as other tips you can try to beat the bitterness.
Making Better (Not Bitter) Espresso
Let’s talk about two main issues in espresso brewing that can cause your shots to taste too bitter:
Shots Flowing Too Slow
A well-balanced espresso should take between 20 to 35 seconds to brew, depending on the coffee and machine you use. If your shots take longer, you may be over-extracting your espresso.
Over-extraction happens when you brew too much of the coffee’s soluble content, including stuff that isn’t very tasty. This can make your espresso taste overly bitter.
Try out these adjustments that might solve this issue:
Move The Grind Setting Coarser
More often than not, you might be grinding too fine. If your coffee grinds feel like flour or cocoa powder between your fingers, then you’ll likely need to adjust your grinder to a coarser setting. Aim for a grind consistency similar to caster or fine granulated sugar.
Use Less Coffee
Overflowing your portafilter basket with ground coffee can also make your espresso taste too bitter. More coffee means more stuff restricting the flow of water through the puck, which can slow down your shot. A high dose can also amplify the coffee’s flavors, including its bitterness.
Using the right amount of coffee to match the size of your basket will increase your chances of a better-tasting espresso.
Similar to an overdosed basket, a tamp that’s too hard will restrict the flow of water through the puck. Don’t skip this step though, as it’s still essential to evenly saturate and extract the coffee.
Our best advice is to tamp just enough to feel the coffee compress slightly against your tamper and no more than that.
Your shots should go ‘drip-drip-drip’ only for the first few seconds. If it does this throughout the entire shot, then you need to speed it up.
Brew Temperature Too High
When it comes to espresso brewing temperatures, we often recommend a range between 195°F and 205°F (90°C-96°C). But if your espresso is too bitter, especially on darker roasts, you might want to err on the cooler side of this range to fix things.
Here are some ways to lower any machine’s brew temperature:
Double Boiler Machines: Adjust The Brew Boiler
High-end prosumer and commercial machines come with dual boilers — one for steaming and another for brewing. The brew boiler usually comes with a PID controller, which allows you to adjust the temperature in single-degree increments.
To lower your espresso’s brewing temperature on a dual boiler, look for a temperature display, and simply press the ‘DOWN’ or ‘MINUS’ button (you may have to press ‘SET’ first).
Heat Exchange Machines: Do A Cooling Flush
Many commercial and prosumer machines (like the Rocket Appartamento) use heat exchangers to handle simultaneous brew and steam duties. Adjustable temperature controls are not common in shared boiler configurations.
We can hack this by flushing water through the empty espresso grouphead longer than normal, before inserting the portafilter with coffee. How long you flush will depend on your machine, but expect it to be more than just the usual one to two seconds.
For extra precision, stick a thermometer right in the water path and estimate the number of seconds it takes to get the water temperature down to your preferred target!
On my heat exchange machine, it takes a 15-second cooling flush to bring the temperature down to my preferred target of 198°F (92.2°C).
Single Boiler Machines: Perform Temperature Surfing
Most entry-level home espresso machines cannot brew and steam at the same time, due to a single boiler handling water-heating duties. They’re also the slowest to get to ideal brew temperatures, and often have a simple light indicator that turns on when heating, and shuts off when the boiler is hot enough.
We can use this indicator to our advantage, by pulling a shot while the light is still on. It’s easier said than done, so you’ll really have to spend some time with your machine to figure out the exact point that’s cool, but not too cool.
Non-electric Espresso Machines: Use Cooler Water
What about espresso makers that work unplugged? Machines like the Flair don’t have an electrically-heated boiler, so you can simply pour slightly cooler water into the brewing chamber.
Other Ways To Solve Bitterness In Espresso
Are your shots still bitter even after you’ve refined your espresso-making technique? You might want to check out these alternative solutions:
Keep Your Machine Is Clean
Rancid coffee oils can get in the way of an otherwise tasty espresso. Always clean your grouphead and portafilters (check under those baskets!). Perform at least a water backflush daily, and use espresso detergent when necessary. More on espresso machine maintenance here.
Pick A Different Coffee
Dark-roasted coffee is traditionally used for espresso. But for some people, it might be too intense or too bitter.
These days, espresso comes in different roast levels and can take the form of a blend or a single-origin coffee. Try what your local roasters have to offer, and remember that the best coffee for espresso is the one you like!
Espresso beans can be of any origin, or any roast level
Add Salt To Your Espresso
There is no substitute for fresh, well-roasted, high-quality coffee. But if you’re stuck with a bean that tastes bitter no matter how you pull it, then you might want to try adding salt. This ingredient enhances acidity and sweetness and decreases perceived bitterness.
Renowned coffee educator and author Scott Rao saw positive results with a 0.15g dose of salt for every 100g of ground coffee. But for those without a microgram scale, try starting with the tiniest pinch of salt in your espresso and, well, add to taste!
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Drink More Espresso
If you’re new to drinking espresso, or black coffee in general, you might be put off by how bitter it is. Thing is, espresso generally has a bitter flavor profile, though it should ideally be balanced by sweet and sour flavors.
Tasting bitterness and nothing else? This recent study by the Flavour Institute at the Aarhus University in Denmark suggests that drinking coffee increases our palate’s sensitivity to sweet flavors and decreases sensitivity to bitterness.
Drinking more black coffee also helps develop your flavor vocabulary, because of how many aromatic compounds are in it. Who doesn’t want to taste coffee like a pro?
Overly bitter espresso is often remedied by adjustments in the way you brew it. If that doesn’t fix things, check your equipment, or choose another coffee that suits your palate better.