Those tattooed bearded baristas make pulling espresso look easy, don’t they? But no matter how hard you try at home, your espresso shots just don’t taste right.
They’re either extracting too quickly or flowing out of only one side of the portafilter or a magnitude of other issues you just can’t put your finger on.
You’ve tried everything, but your espressos are just not good enough, no matter what you do.
If this sounds like you, you’re not alone. And yes, those baristas do make it look easy.
If you’re experiencing problems when pulling a shot of espresso, the most common cause for most issues is “espresso channeling.”
The good news is with a bit of practice, and by tweaking a few of your brewing parameters, you can knock all of these problems on the head.
Want to pull the best shot of espresso you can? Keep on reading and make sure you’re not making any of these mistakes.
Channeling In Espresso – What Is It?
So what is channeling?
Simply put, when pulling a shot of espresso, channeling is when water finds the path of least resistance and doesn’t flow through the entire coffee bed evenly.
Over the course of the brew cycle a channel in the coffee will have a faster flow rate than the rest of the puck.
This suggests that the coffee grounds in those channels will have more extraction than the rest of the puck, which will lead to unbalanced flavors in your final shot.
Why Is Channeling Bad?
I’m sure you can already see why espresso channeling is bad – it ruins the flavor and clarity of your espresso.
Ideally, the entire coffee puck would have the same amount of water during the complete brewing cycle.
This would effectively mean that every coffee particle has the same amount of extraction.
But, because espresso channeling causes some areas of the coffee puck to get more flow and others less, it messes up your extraction by over and under extracting different areas of the puck.
The resulting shot of espresso will have muddied, unclear flavors – it’s not the best it can be.
Signs Of Coffee Channeling
The signs of espresso channeling can be hard to spot.
After all, your portafilter is locked in the group head of your machine, so it’s impossible to see what’s going on during the extraction – or is it.
If you think you might be having issues with coffee channeling, the best thing you can invest in is a naked portafilter.
The standard portafilter that came with your espresso machine more than likely has a closed bottom with one of two spouts – a “spouted portafilter.”
But with a naked portafilter, you have a flat bottom with lots of holes.
The added benefit of this is that you can see precisely how your espresso is filtering through the coffee puck. And you can quickly see potential problems as they happen.
If you’re having channeling issues, you will be able to easily see when and how with a naked portafilter.
If you don’t have this type of portafilter, you’ll have to do some good old investigating work by examining the puck once you’ve removed the portafilter from the machine.
Nevertheless, this isn’t as accurate as closely watching the espresso extraction in real-time.
Many changes happen in the machine as soon as the brew cycle stops, which can change the appearance of the puck before you get a chance to examine it. Still, you can use the expired coffee puck as a guide to try to pinpoint issues.
Signs of espresso channeling include:
📌 You notice your espresso shot starts too quickly.
If you find that your espresso is coming out sooner than expected, even before pressure has entirely built up, you may have channeling issues.
Examine the espresso as it comes out and look for dark thin watery fluid that quickly blondes. The stream might also have stripes of blonde and flecks of darker colors too, depending on the severity of the channeling.
But any indication of early blonding is a telltale sign that there are problems hidden in your filter basket.
📌 A lack of crema or a very pale crema.
This could also indicate the quality of your coffee beans, grind, and dose. So use this in conjunction with other warning signs.
📌 Your espresso shot “feels” one-dimensional.
It has a weak flavor, is flat, dull, and lacks acidity are all potential indicators of channeling.
📌 If your espresso machine has pre-configured time-based brew settings and your shot of espresso is pulled faster than it should be, you may have a problem.
📌 More water in your shot of espresso than expected is an indication of channeling or other issues.
📌 Once removed and on closer inspection of the used coffee puck, you notice small holes or groves.
Now that you know how to spot espresso channeling, what can you do to reduce it or avoid it altogether?
How To Stop Espresso Channeling?
What causes espresso channeling? Once you’ve identified that you have an espresso channeling problem, you can take steps to stop it.
Before anything else, you should look at your recipe and your coffee grind. If the foundation isn’t up to scratch, you are setting yourself up for failure.
Even distribution of ground coffee is essential.
The more evenly you can distribute the coffee in the portafilter basket, the less likely you will see channeling.
Distribution starts the moment the ground coffee comes out of the grinder. Try to spread the grounds around the filter basket by moving your portafilter in small circles.
Once you fill your filter basket, you need to use a good espresso tamper and/or a distribution tool.
When tamping your coffee, make sure the coffee bed is as level as possible. Even the tiniest slant to one side or the other will result in one half being more resistant to the flow of water than the other.
Finally, I strongly recommend swapping out your regular portafilter for a naked portafilter so you can easily see any problems as they occur.
You can tweak and make changes and monitor each pull until you’ve ironed out all of the issues that are causing the espresso puck channeling.
If you’re happy with the grind, your recipe, distribution, and tamping pressure, try to pull your shots at a ratio between 1:1 and 1:2.5 within 20-35 seconds.
So there you have it. If you have reached this far, you should know how to fix espresso channeling and the telltale signs to look for.
Remember, a good shot of espresso needs a solid foundation. By that, I mean the correct coffee grind, good quality espresso bean, even distribution, and a firm tamp.
The easiest way is to invest in a bottomless/naked portafilter if you’re having problems. What would usually be hidden from view you will be able to see.
You can then play around with your coffee grind and dispersion using a distribution tool and a leveler until you nail the perfect shot.
Whenever I have an espresso channeling problem, the first thing I tend to do is immediately examine the used coffee puck.
Almost always, I will see tiny holes along one edge of the puck. Next time, with all brewing variables being the same, I will focus on my tamp.
I then try to fix my espresso channeling problem using a nutating technique.
This is where I run the tamper around the edges of the portafilter, lightly in a circular motion, twisting and then polishing to help ensure an even distribution of the ground coffee, then I apply my final tamp.