What Make a Good Espresso?
A good expresso will depend on the right grinding of the coffee bean. A good espresso takes around 30 seconds to extract and be about 30ml. Any extractions faster than this will result in not enough flavour being extracted, and the drinks will be weak. When the grind is too coarse, the grounds will not pack tightly together, and the water will pass through them too quickly. The extraction will be too fast, and the drinks will be weak. You must make the grind finer.
If the extractions take longer than 30 seconds, they will be bitter. When the grind is too fine, the grounds will pack too tightly together, and it will be harder for the water to penetrate the coffee puck. This will result in an extraction that is too slow, hence bitter drinks. You must make the grind coarser.
When to Adjust your Coffee Grinder?
Commercial grinder calibration should be done every morning before the opening. Many café or expresso bar ignore this due to poor knowledge and lack of skill. This will result in inconsistent and poor tasting expresso.
How to Calibrating Your Grinder?
A double espresso is prefer when calibrating your grinder. Load and tamp a double espresso dose around ½ ounce into the double group handle and lock it into the coffee machine. Push the button for the double expresso and start the kitchen timer.
A correct grind will cause the flow to start about 4 seconds later. It will be smooth and constant and the crema will be golden brown. If the grind is too coarse, flow will like to start in 3 seconds or earlier and be noticeably fast and extraction will not be smooth. There will be very little crema and the extraction will look pale. The extraction time will continue past 30 seconds. Crema will be dark and the brew will taste bitter.
The grind can be easily changed by rotating the collar on your commercial coffee grinder. Refer to the user manual for instruction.
The collar should have a “legend” on its top surface that indicates which way it should be rotated to make the grind finer and coarser. The “legend” may be arrows with “+” and “-” or “Coarse” and “Fine” signs. For most commercial coffee grinders, rotating the collar clockwise will make the grind finer, and rotating the collar counter clockwise will make the grind coarser.
How to Adjust the Collar?
Firstly, empty the chamber of the (previously ground) coffee, This can be done by repeatedly pulling the dozer lever until no more coffee comes out. Find and press the collar release button, and rotate the collar in the appropriate direction to make the grind coarser or finer, as needed. Put the hopper back onto the coffee grinder, and open the gate. Grind enough beans to fill the dozer, and load up another Double Expresso.
Re-time the new Double Expresso. Repeat the process if further adjustment is needed until you get the correct setting.
You can save the ground coffee that you empty from the chamber for uses other than espresso. You need not discard it. Use it for regular or iced coffee.
The standard espresso drink is the double espresso
Here are some characteristics of a quality doub tle shot:
o The espresso should be quite hot when served. If it is only lukewarm or warm right after it is made, then the barista did not heat the cup that it was served in or there is a problem with the machine.
o It should be to the temperature where it is too hot to drink (for most people). It should only take a minute or so to cool off. Maybe two minutes.
o There should be a nice layer of crema on top of the espresso (a few millimetres thick, completely covering the espresso). This comes from the release of carbon dioxide when the espresso is extracted under pressure.
o The color should be golden-brown to dark brown for a double shot.
o The color will not always be uniform; it will sometimes be slightly lighter where the shot actually poured in the spot on the crema.
o The crema should remain for at least three – five minutes if not longer.
o The espresso should be bitter, but not too bitter (high levels of bitterness are more characteristic of espresso long shots).
o It should be rich, but not too rich (again, high levels of richness are more characteristic of espresso ristretto shots).
o It should NOT be sour. If it is sour, it has been sitting for too long before being served or was over-extracted.
o It should not taste watery, this is usually a characteristic of under-extraction.
o Hard to describe for espresso and the aroma will vary a lot. One thing to avoid is a ‘sour’ smell, which usually indicates a sour taste, as described above, or that the coffee being used is inherently too acidic.
o Espresso is going to be thicker and more viscous than regular drip coffee, but it won’t be syrupy. When you are done your espresso, the drop or two that remain at the bottom of the cup, when dried should leave a distinct brown residue on the bottom of the cup.