If you prefer your coffee with a bit of crema on top, we would like to share some tips for making delicious crema-rich espresso using Leverpresso’s tamper.
For those that are unfamiliar, crema is a thick, golden layer of foam formed on top of coffee during the brewing process.
To put it simply, espresso is coffee syrup. The coffee powder is tamped, or compressed, so that water pressure is passed through. The components that are relatively soluble in water, including fine coffee powder, carbon dioxide, and caffeol (coffee oil), emulsify and become highly viscous.
This process causes fine powder, collagen, and caffeol to float on the coffee instead of settling down. This layer of foam, or crema, is dense and helps to keep the espresso from cooling down quickly.
Before you start, these essential steps will provide you with the best coffee-making experience:
- Coffee beans (coffee oil, carbon dioxide)
- Grinding (pressure)
- Tamping (pressure)
- Lever lowering speed (pressure)
You need fresh, well-roasted beans.
There are three different kinds of coffee roasts: light, medium, and dark. The lighter the roast, the more acidic and the more taste that is retained. The darker the roast, the more bitter and the caffeine levels will be decreased.
When roasting coffee beans, gas is generated. As this gas (mainly carbon dioxide) is discharged, it pushes the grease out of the coffee beans, so the oil expunges. This coffee oil plays an important role in the emulsion action and crema, mentioned earlier.
The problem is that if this coffee oil is exposed to the air for a long time, it dries and acidifies, thereby failing to take the aforementioned action properly.
After a month or two from the roasting date, the coffee oil acidifies. Thus, the above-mentioned action can't take place properly.
Because of this, it is recommended to purchase as small a quantity as possible and to ask about the roasting date when buying coffee beans. After the beans are ground, the surface area becomes larger, which leads to faster acidification and moisture acquisition. The recommended method is to grind fresh beans close to the roasting date, just before extraction.
You need to grind fresh beans 'moderately'.
Once you have fresh coffee beans, you need to grind them to a 'moderate' size. If you grind them too small, they may become overly pressurized, resulting in espresso that is too bitter, or even make extraction impossible. On the contrary, if it becomes too large, there is no pressure, so a cup akin to drip coffee may be extracted.
The one on the left is the size of sugar generally used, and the size on the right is the size of our beans.
We are extracting espresso at a sugar-like size, 0.3~0.5mm. It's a bit larger than the actual espresso (less than 0.3mm). However, it may be difficult to visualize it like this.
When you ask to grind the beans, it is recommended to ask that it be done a bit thicker than espresso, but a bit smaller than for a moka pot (your typical electric coffee maker).
If the size of the ground coffee beans is larger or smaller than that scale, adjust the zero point to grind a smaller or larger size. From there, if you adjust the size according to your taste, you can extract delicious espresso that suits you.
Let's do tamping.
In order to get espresso, you have to tamp the coffee. However, if you use 18g of espresso beans, it can be too much.
Don't panic. First, make an OK sign with your fingers to make a dosing ring and add the coffee powder. Shake it a little or tap it on the floor to do it well. Don’t try to put it in all at once.
Of course, use a dosing ring if you have one.
It is necessary to shake it and smooth it out.
After that, press it tightly with the plastic tamper included with our product.
At this time, it is good to press down firmly using the middle of the palm to flatten the grounds. The most important point of tamping is to flatten evenly and strongly. If tilted to one side, channeling may occur, wherein water is drained to the tilted side.
Normally, the tamping is done with a vertical force of about 20kg. Of course, depending on the degree of grinding or the degree of roasting the beans, it can be adjusted.
Now, you are ready to extract. First, pour hot water with the lever down, then pull the lever up and pour in water again. It is designed to allow you to pour more water while the lever is up.
Shall we let it sit a bit (Pre-infusion)?
When the lever is slightly lowered and raised, air bubbles rise like this. You can leave it like that for 5 to 10 seconds. After this process, the water and coffee puck meet and coffee is extracted from the coffee powder.
You don't need to press the levers too hard. Just push them down gently with natural body weight.
It looks like 3-4 seconds here, but it was actually extracted slowly for about 30 seconds!
If your arms are too far apart, you can't create pressure. You just need to put your arms down close to your body. The closer the shoulder and the lever, the easier it is to extract.
However, if the shoulder line is over the Leverpresso, excessively high and unstable pressure may cause injury, so be careful!
If it goes down too fast, it's either that the grind is too large or the tamping is too weak. If the lever is too tough to push down, the grind is too small or the tamping is too strong. If you adjust the parameters from these steps, you will surely be able to extract the espresso that suits your taste.
Once you have grinded your roasted beans, tamped the grounds and have extracted, you are now ready to have delicious coffee using Leverpresso's new basic tamper.
Enjoy your crema!