Thursday, January 26, 2012

The heart of espresso

Extraction into Bodum Pavina espresso cup
When brewing for espresso shots their is a lot of variables that you need to control to produce the perfect shot. This were especially one of many things that got me hooked on coffee brewing. See I like having a challenge, I like to put in an effort and being rewarded and I definitely like things to change a bit, so it won't get to boring. In brewing for espresso all these are answered and Im put to the test every single time, which I love about it. I can shortly mention the variable areas that you need to have focus on;
                              Get the right fresh roasted beans, which is roasted properly.

                              Grind the coffee beans exactly right for the machine you are using.

                              Tamp the coffee even and with enough pressure to create a puck without

                              Brew the espresso shot with fresh water at 95 degrees and under a 9 bar pressure.

                              Control the extraction time and brew in a preheated cup.

There is a lot to keep in mind for the inexperience coffee enthusiast and certainly for the more for the experienced ones. When you first have tried a perfect shot and experienced the magical flavors of the coffee beans, you will be in a constant hunt for more, leading to lots of testing and cupping. I once had a espresso shot that was so unbelievable sweet with heavy notes of ameretto, which for me tasted like heaven.

Other think to know about an espresso shot, is that is brewed in three different stages. The first stages is were the espressos dark and powerful flavors is extracted and the last stage is the bitterness of the shot. In between these two are the sweetness of the shot, which is sought by a lot of baristas. There are some that only extract the sweetness and how do they do that? Its fairly simple, just brew the espresso shot, wait a few seconds for the dark extraction to go though and when the espresso turns reddish dark brown pul your cup underneath. When the short shows sign of turning to blonde crema remove the cup and there you have it.

Pouring art using two spoons
So I have seen the picture above and it looks amazing, how do I get a shot like that??
Well actually having the right gear is half the way, so it depends a lot of your present status of coffee gear and gadgets. That being said, there is a lot of routines and knowhow that has to be in order for the shot ever to appear. If you are certain that you will give it a go, here is the way I would analyze and adjust my methods;

                           Buy a pack of freshly roasted beans from your local coffee shop.

                           The most important is to have a very good grinder, so purchase one!

                           Start by grinding a baseline (Grind a setting that you think are the right)

                           Tamp the coffee and give it a go!

                           If you are using a single basket, you should have about one oz of espresso in 22-25
                           sec. If you have more the 1 oz after the time period, you have to grind finer and if you
                           have less, grind coarser.

                           When the grind setting is right you should experience a positive difference in the taste
                           of the espresso shot. It should have more precise flavors and bring a lot more tasteful.

                           Check with a thermometer if the water temperature is 95 degrees by starting the pump
                           in the espresso machine and check the water temperature without the portafilter.
                           Some espresso machines have a PID, which allows them to adjust the brew
                           temperature, but if yours do not have one have a talk with the local coffee shops for
                           any help or search the web. It is different from machine to machine how to adjust the
                           brew temperature.

                           The brew pressure is harder to adjust because you need some equipment and locating
                           the OPV on your espresso machine, again search the web for your exact espresso

Espresso extracted on the Rocket Giotto
Diagnose espresso extraction problems
Lemon peel, This can be a blending or roasting error and irreparable. Short term, start-dump the shot. Long term, set the temperature higher and make sure the grinder burrs are sharp. This flaw comes from fines of very high quality coffees, and good blends tend to flirt with it.

Metallic, Recently cleaned machines or brand new ones can have this. The taste is eliminated most quickly by flushing more after cleaning or for new machines, pulling a lot of shots and dumping them. Dull burrs are another cause. Finally a failure in the water treatment resulting in almost distilled, low mineral water will cause this.

12 hours on the hot plate, Time to back flush and clean the portafilter. Verify the frequency of your cleaning schedule.

Instant coffee taste, The mark of over extraction. Grind coarser and stop darker, so volume stays the same. If the bitter taste is prickly-sharp rather than dull, also lower the temperature.

Thin and sourish, The mark of under extraction. Grind finer and stop lighter, so the volume stays the same. If the taste is extremely sour, also raise the temperature.

Ashiness, Usually a flaw in rapidly dark roasted, low grown coffees. Drop the temperature to the low end of the espresso range. Dial in to the lung end of the optimum crema range and dark stop the shot. These measures will not reduce the ashiness a lot, but will mask the problem with a little more brightness and crema. The real solution is to change blend.

Rubber or Iodine, Buying cheap coffee? This is the classic reason for start-dumping.

Sewage, decay, mold, sausage or cabbage smells, This is from badly fermented coffee. If the blend is normally good, its from a stinker bean. Clean out the doser and burrs. If it keeps happening there is nothing you can do except get new coffee. 

Not sweet enough, Do more ristretto shots, grinding finer and stopping at the same color. This will take the shot out of the optimum crema range, so it has to be a good crema blend. You can also center out the shots, however, this will reduce the distinctive flavors and can lead to blandness. On the other hand, somewhat blend center cut shots are good way to serve newcomers to straight espresso.

Over-intense flavors, Lover the pump pressure. If this because there is not enough sweetness to balance the bitters and sours, use the previous fix. Also consider going more lungo with the same stop color.

Pallid flavors, Raise the pressure. Also consider going more ristretto with the same stop color.

Overly sour, Raise the temperature. Short term, trying stopping lighter and grinding finer to keep the volume the same. If its really bad start dump.

Overly bitter, Lower the temperature. Short term, try stopping darker and coarsening the grind to keep the volume the same.

The section about espresso extraction problems has been quoted from Hope this was helpful and remember to join your newly establish Facebook site; Coffee Channel.

// Hendrup

1 comment:

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