A common misconception is that making an espresso is easy, just put some ground coffee in the portafilter, stick it in the espresso machine, press the button, and PRESTO out comes the nectar. Well, making bad espresso is that easy, but making good espresso is a little more challenging.
Fresh quality beans, the perfect grind, the right amount of ground coffee, the ideal extraction time, and a yield that is double the weight of your ground coffee is the start to a great expresso. One way to tell you’re on the right track to decent espresso is to look at the crema. Does it hold on the surface if you tilt the cup? Is it caramel in color? Is it thick and creamy? If not, how do you make this happen? How do you get a good crema?
To get a good crema, you must have a good espresso. To make a good espresso, all of the following factors must be considered: the correct coffee dose, the coffee yield, grind size, and a suitable extraction time. Once all these things are don’t correctly (which I will explain), you should have a delicious espresso and a good crema.
Now let’s dig a litter deeper into each of those factors so you too can make the perfect espresso with fantastic Crema!
‘Dose’ is the amount of dry, ground coffee you put in your portafilter (group handle). The amount you dose is determined firstly by how much your portafilter will hold. For a double shot (baristas always talk in double shots, and never in single shots, because they don’t ever pull single shots) on a home espresso machine, you’re looking at about 15g, in a larger or more commercial machine, it’s usually 18g, but can be anything up to about 20g.
To determine a good dose for your espresso machine, fill the portafilter with ground coffee and then tamp it. If it’s between 2/3 and ¾ full, that will be a good place to start. Make a note of how much that weighs. The second thing that determines how much coffee you dose is how much yield you would like.
The yield is how much coffee (espresso in this case) you extract from your dose. In specialty coffee, most people use a 1:2 ratio as a starting point. So, if you’re dosing 15g of coffee, you will want your yield to be 30g of espresso (that’s about as small as a double espresso gets).
Why a 1:2 ratio? Because over time, this is where baristas have most found the “sweet spot” of the espresso. This is where you can get the most from the coffee and produce an espresso that is not too bitter, acidic, or sweet, but a nice balance of all of these things. A 1:2 ratio isn’t a blanket measurement always used for all single origins or blends of coffee, but it’s usually a starting point to try.
If it’s not quite as balanced as you would like it, you can change the dose, yield or extraction time from there to get to where you want to be with the espresso. There is nothing wrong with a 1:3 ratio or anything else if that is how you like it. I have seen an 18g dose, with up to a 60g yield, and if that’s your preference, go for it.
Grind size is possibly the most crucial factor in getting the perfect espresso and crema. If you grind too fine, the water will not be able to get through the coffee in your portafilter quick enough (here you might get a crema, but you won’t get a tasty espresso. Instead, you will get something bitter and over-extracted).
Grind the coffee too coarse, and the water will run through so quickly, you probably will not get a crema at all. If by chance you do, it will be thin and pale, and your espresso will taste insipid. To get your grind size correct, make sure you keep your does and yield constant and adjust the grind size accordingly to get the desired extraction time.
If the espresso is running off too quickly, make the grind finer. If it is running too fast, make the grind coarser. A good starting point is a grind that is similar in size to table salt.
Extraction time is the time it takes from pressing the button on your espresso machine to having the desired amount of espresso in your cup. The ideal time for espresso to extract is usually between 28 and 32 seconds.
Anything less than 25 seconds and the coffee will most likely be under-extracted. It will probably taste overly acidic or insipid because the water has run through the coffee so quickly and with little resistance that you extract very little from the ground coffee. You may also not get a crema, or it will be pale and thin if you do.
If it’s too slow (more than 35 seconds), you will get more bitterness than desired, and probably a thick and not very tasty espresso, but you will probably still get a crema.
How to Know if Your Crema is Good?
First, you have one – that’s the best start, and if you follow all of the above guidance, it should be there. Next, does it stick to the sides of the cup if you tilt it? If it does, great. If it breaks straight away, not so great. Color-wise it should be a deep caramel color. If it’s a few different shades of that color, that is good. Lastly, if it has flecks of dark brown in it, then even better.
These are all superficial things to look for. Not all coffees give you a fantastic crema. Often South American coffees/blends that are roasted slightly darker give you an amazing crema. And sometimes, light roast African coffees give you a less lovely crema.
This does not mean you have not pulled a great espresso; the only real test is how it tastes. If you like it, and you have pulled your shot in your desired time, with your intended dose and yield, that is what matters most.
Crema doesn’t taste that great, and if you’re drinking espresso correctly, you’ll be giving it a good stir before drinking anyway, so the crema will get mixed in. There was a time when coffee geeks scooped it off their espresso before drinking it because they thought it made the espresso less desirable. So definitely don’t place too much importance on it.
However, on the flip side, a nice thick crema does help with latte art, so if you’re making a great looking (and tasty) flat white, you’ll probably want decent crema on your espresso.