This guest Blog post is brought to you by Oli Baise, barista and owner of coffee blog Drinky Coffee.
There are a few more important variables involved in brewing espresso compared to filter coffee.
This means that it can be difficult to replicate the espresso that you get in a coffee shop at home.
While using commercial equipment allows coffee shops to (quite literally) squeeze every drop of quality from their espresso, you can still get close to producing as good an espresso at home if you follow certain brewing guidelines.
Here we are going to go through the steps you need to take to make close to coffee shop quality espresso at home.
Brew With As Good Quality Beans
One of the most variables in your espresso is the type of beans that you use.
Since espresso brews your coffee at high pressure, lots of soluble compounds in your ground coffee end up in your final drink.
With lower quality beans, many of these soluble compounds do not taste good. They are either too sharp or too bitter.
Higher quality coffee beans will create a more balanced final espresso, not too sour and not too harsh.
Darker roasts also tend to work better for espresso than lighter roasts. Please see our article on different coffee roast types if you’d like to learn more about this.
Use the Ground Coffee Dose Specified on Your Portafilter’s Basket
A portafilter is the removable part of the machine which holds your ground coffee.
The basket is the removable metal tray in the portafilter where your ground coffee sits
Every portafilter basket was built to hold a certain quantity of coffee.
If it holds significantly more or less than this specified amount, then the ground coffee will not get proper coverage from your brewing water. This will result in an uneven extraction which creates a harsh, bitter final drink.
A portafilter basket’s ideal ground coffee capacity is often printed on its side. If you cannot find it there, then it will be in your espresso machine’s manual.
Use this specified weight as a fixed variable in your brewing recipe and determine the amount of water you use to meet the 1:1.5 brewing ratio from this fixed variable.
Brew to a 1:2 Ground to Liquid Coffee Ratio
Espresso should be brewed with a ratio of one part ground coffee in to one and a half parts liquid coffee out.
This brew ratio is delicate. An espresso brewed to a ratio of 1:2 ground coffee to liquid coffee will taste drastically different to one brewed at 1:1.5 ground coffee to liquid coffee.
The only way that you can therefore measure out brewing ratio reliably is by weighing both your initial ground coffee dose and your final espresso.
Measuring your final espresso by volume, rather than by weight, is not reliable because the layer of crema that sits atop your espresso vastly increases its volume without actually adding that much more liquid to the drink.
You will need a small scale that measures to the nearest gram to do this. The scale needs to be small enough that it can fit under your cup as you brew your espresso.
Once the liquid coffee in your cup is twice the weight as your initial dose of ground coffee, you should end your shot.
If You Have a Grinder, Then Use Grind Size to Adjust Your Espresso’s Flavour
As mentioned earlier, small tweaks in the quantity of ground coffee that you brew with can drastically affect your espresso’s flavour.
You are therefore better off fine tuning your espresso’s taste by playing around with the grind size of your coffee, rather than the quantity of coffee used.
A finer grind size exposes more of your coffee’s surface area directly to your brewing water. This results in greater extraction and a stronger tasting final drink.
If your espresso tastes a bit weak, then you want to grind finer. If you find it to be harsh tasting, then you should grind a bit coarser.
If You are Using Pre Ground Coffee Then You Should Brew With a Pressurised Portafilter
While we would recommend grinding your own coffee for espresso, so you can control the grind size, you can still make a good espresso with pre ground coffee if you use a pressurised portafilter basket.
Pressurised portafilter baskets have a single hole in its bottom (as shown by the red circle in the image below). This contrasts to non pressurised portafilter baskets that have dozens of holes in their bottom.
The single hole in a pressurised portafilter creates a bottleneck where water cannot pass through it quickly. This increases the amount of contact time between your ground coffee and brewing water, increasing extraction in the process.
Since pre ground coffee is usually coarser than freshly ground coffee, it needs this additional contact time with water for proper extraction.
Finer ground coffee naturally creates more resistance for brewing water as there is less space between each ground that water can pass through. It does not therefore need this additional pressure from the single holed basket below it.
Most espresso machines come with both pressurised and non-pressurised portafilter baskets, allowing you to brew with both freshly ground and pre ground coffee.
Hopefully you now understand how to use your espresso machine to its full potential.
If you are interested in putting these skills to the test, check out our coffee subscriptions.
This article was written by Oli Baise, barista and owner of coffee blog Drinky Coffee.