A common process in the barista world is the calibration and dosing in the preparation of espresso, with the aim of extracting the best possible espresso. However, this is something done with a pump coffee machine. How can it be done with a super-automatic machine, if it can be done at all?
The concept is the same, but the process changes. It is about extracting the coffee at a ratio of 1:2, that is, doubling the amount of coffee I am using. So, if I use 20 grams of coffee, I must extract a cup of 40 grams, exactly double, and all within an extraction time of between 20 to 30 seconds.
In the world of specialty coffee, these values are well-established as a method to achieve an intense espresso, revealing the aromatic profile and unique notes of the coffee beans being used.
First step: know how many grams of coffee the machine uses during grinding
The first thing to understand is how our super-automatic works, specifically how many grams of coffee beans it grinds with each of the intensity settings it has programmed. These intensity settings are nothing more than the dose of beans the machine uses to prepare the coffee.
That’s a piece of information that is not usually indicated in the machine’s menu or in the instruction manual, so to know it, we will have to perform a small trick that consists of weighing the coffee the machine has just ground with a scale. For this, it is advisable to get a coffee scale, although a kitchen scale will also do.
First of all, make sure the coffee grounds drawer is clean and without coffee residues inside. Remove it from the machine, place it on the scale, use the tare function, and then reinsert it into the coffee maker.
Now prepare an espresso with the highest intensity setting, but stop the preparation just after the grinder finishes grinding. What the coffee maker will do is expel the freshly ground coffee into the grounds drawer, so we can take it and put it on the scale, and thus we will know the dose the coffee maker uses for that setting. We do the same with all the intensity settings the machine has.
In the coffee maker I used for these tests, the splendid Magnifica Plus by De’Longhi, these settings are 30 grams at level five, 28 grams at four, 26 grams at setting 3, 23 grams at the second, and 20 grams at the first. In this case, I will stick with the first intensity setting, which is the closest to what is usually used in the world of specialty coffee, which is 18 grams.
Programming the volume to achieve the 1:2 ratio
Remember that the 1:2 ratio means that we double the cup drink volume compared to the dose of ground coffee used. In this case, 20 grams of coffee should be equivalent to a 40-gram espresso (approximately 40 ml). If the coffee maker does not come with a programmed volume setting of 40 ml, then I will have to reprogram it, something that any super-automatic coffee maker allows, even the cheapest one.
In your case, if the dose the coffee maker uses is much lower – let’s say it’s 10 grams – then the ideal volume would be 20 ml, at most 25 ml. Using a higher volume – 30 ml or more – would result in a very weak, watery espresso, without body and intensity. This problem is what many super-automatics, especially older or budget models, suffer from, as they use somewhat low coffee doses.
At the same time, you must also monitor the extraction time. For espresso, this is between 20 and 30 seconds: if we fall below 20 seconds, the coffee is under-extracted, and if we go above 30, it is over-extracted. In either case, we get an espresso that will leave much to be desired in terms of body, aroma, and intensity.
So you will probably see that the espresso is extracted too quickly. In this case, you need to lower the grind level to finer settings. It is about gradually lowering, one by one, until you hit the mark. At the moment you see that you achieve that 1:2 ratio and with an extraction time of between 20 and 30 seconds, you will know that you have optimally extracted the coffee.
Calibration in a super-automatic espresso machine differs from that of a pump coffee maker, although the goal is the same: to achieve the best possible espresso with the tools at hand.
But beware, be careful not to overdo it by lowering the grinder setting. One of the drawbacks of super-automatics compared to manual espresso machines is that they do not work as well with very fine grinds, especially with Arabica beans and light roasts. If you use such coffee with a low grind setting in a super-automatic, you may find the opposite situation, where the coffee is extracted excessively slowly, and not fluidly, but rather dripping.
You should also keep in mind that changes in grinder settings take time to take effect, so you must be patient, perform the calibration step by step, and not certify the changes until you have prepared two or three more coffees.
