This is why your espresso tastes bad (and how you can fix it)

Perfecting the at-home espresso can be fun, rewarding and will save you an awful lot of money on coffee shop trips. But getting to grips with a manual espresso machine involves getting over a potentially steep learning curve. There are a lot of variables and there are plenty of things that could go wrong.

You shouldn’t let this put you off though. Here at Expert Reviews, we’ve reviewed enough coffee machines by now to recognise the most common pitfalls when it comes to making espresso. Below, we’ll give you a rundown of these.

Over-extraction and under-extraction

One of the common complaints people have about their espresso is that it is too bitter or too sour. There’s a good chance the cause of this is to do with the extraction of the coffee.

What exactly is meant by extraction? Without delving into a chemistry lesson, when water comes into contact with ground coffee, soluble compounds including acids, sugars and oils are drawn out from the beans, which gives us the flavours we associate with espresso. There’s a bell curve to consider here: extract too little and you’ll only get the sour, acidic notes from the coffee. Extract too much and the espresso will taste bitter, because the water has pulled out all it can from the coffee including the bitter plant fibres. The middle point between these is a perfectly balanced espresso.

The process of extraction is key to all coffee brewing methods, not just espresso; espresso brewing perhaps the most unforgiving. A few of the things to think about here are dose size, grind size and – to an extent – the type of coffee you’re using.

Dose size

The size of your dose, which is to do with how much ground coffee you put in your portafilter basket, will vary depending on what machine or, more specifically, what basket you’re using. These will usually come with recommended dose weight sizes – often 7-9g for a single shot basket and 16-18g for a double shot. It’s a good idea to stick to these recommended doses, so make sure to check the manufacturer’s suggestions.

It’s not just weight that’s important when it comes to dosage, volume is also crucial. If there’s too much or too little space between the top of your coffee puck in the basket and the machine’s shower head, you’re going to end up with a spoiled shot and a messy puck. It’s hard to recommend an optimum headspace – that’s the gap between the shower head and the top of the puck – but some people suggest a trick involving placing a thin metal washer or a clean penny on top of your coffee. Lock in your portafilter before unlocking it again and if your dose is correct, you should have just a slight indent where the washer was.

There are also tools available, such as Sage’s dosage razor, which can help you to get your espresso dose right.

Grind size

Grind size also has a huge effect on extraction. You want to grind finely for espresso; too coarse and the extraction time will be too quick and you’ll end up with a sour cup. On the other hand, if your coffee is too fine or densely packed the extraction time will be too long and your espresso will be bitter. The type of coffee you use will in part determine how fine you should grind your coffee so, when switching to a new roast, expect a process of trial and error. I would suggest starting with a very fine espresso grind and then adjust depending on results.

READ NEXT: Best coffee grinders

Type of coffee

The type of coffee, specifically the type of roast, is going to change the flavour of your espresso however you cut it. And while that’s no bad thing, you may need to play around with your settings when switching coffees to get the best you can out of it. Traditionally, darker roasts have been used for espresso because their flavour profile complements espresso’s naturally quicker extraction time as opposed to, say, brewing filter coffee in a cafetiere.

That’s not to say you can’t use lighter coffees for espresso but first timers may be a little taken aback by the flavour profiles of some roasts.

What about pod machines?

Opted for a pod machine instead of a manual espresso machine? These can be great for convenience’s sake, saving a lot of time and effort. Plus they’re easy to use too. However, the quality of the espresso will never match that of a manual espresso machine for a number of reasons. First of all, there’s simply not enough coffee in those little pods and secondly, it’s not going to be as fresh.

If you’re a faithful pod machine user and your espresso starts tasting bad, consider also the possibility that the machine needs cleaning, that there’s a fault or perhaps you’re using a bad batch of pods.

READ NEXT: Best Nespresso compatible pods

What’s the solution?

Given all the variables involved, including what machine, portafilter basket and coffee you’re using, it’s impossible to provide a one-size-fits-all recipe for the perfect espresso. So, how do you fix a bad shot?

Inevitably, there’s going to be a lot of trial and error involved. But that’s part of the fun of making manual espresso and finally dialling in the perfect shot for your setup can feel very rewarding. Ultimately, we recommend playing around with all of the factors discussed above, taking into account such things as the type of coffee you’re using and grind size and tweaking your settings accordingly until you get a result you’re happy with.