The Rules Of Engagement: Pulling the 'Perfect Shot'.

The key to espresso is the understanding that it is not coffee. Espresso is the suspension of solids, primarily oils and sugars, extracted from beans under high pressure. Under normal brewing procedures, the flavor components that make up espresso are never realized. Coffee is in a tie with distilled alcohols for its contributions to humanity. While readily available today, coffee and its importance to religion, social and creative implications cannot be underestimated. Espresso is the culmination of the very coffee experience. Success in coffee today won't happen with a cookie cutter shop pushing out mediocre drinks. Atmosphere and quality are the key.

  
a section of our espresso lab.
Here are the basic 'rules' of espresso production:
  1. Proper equipment. Espresso is extracted between 9-11 atmospheres of pressure, and at a temperature between 197-204f. Coffee is dirty, and water is lazy. Portafilters, and group heads need to be cleaned daily to remove the coffee residues, and maintain proper water flow. Grinders must also be cleaned of coffee residue, and grinder burrs need to be regularly changed.
  2. Good water. Water with a specific mineral content, of a specific ph, and of a given purity is necessary to create perfect espresso. As city water can change from time to time, once the initial water tests have been conducted, the easiest test is to taste the water regularly. (Send us a sample of your water for testing!)
  3. Grind. In a production setting, as long as all other factors remain constant, grind is the one variable that will affect a perfectly timed espresso 'pull'. Always grind espresso just prior to its use. Fresh ground espresso acts as a sponge, and will immediately begin to absorb moisture and odors from the air.
  4. Dose and Tamp. Dose enough espresso into the portafilter so that it is 'too full'. Swipe off the dose so that it is level with the rim of the portafilter basket. Tamp by evenly applying 30-50 lbs. of pressure to the dose, creating an even surface, and an even density of espresso for the water to flow through.
  5. Pull Espresso. The critical measurements to a shot of espresso are; 1-1.5 ounces of water passing through the espresso in 23-28 seconds. The espresso should ooze out of the portafilter like warm honey. If the espresso pulls faster than 23 seconds, adjust the grind finer. If the espresso pulls longer than 28 seconds, adjust the grind coarser. Do not adjust tamp pressure or dose amount to compensate for times!
  6. Inspect. Even with all of the above steps, the ultimate judgment is the actual appearance of the crema. A thick, rich caramel foam topping the actual shot underneath.
 
shots pulling from a piston machine.
Now let's discuss these elements. What do they really mean in practice?

Clean equipment: It's a slow digression. Let a couple of weeks/months pass without cleaning the grinder or portafilters. The fouled oil residues will cause a sour/ acrid 'bite' to the shots and the crema will disappear rapidly on the shots.
Cleaning is simple and should be made a regular part of cleaning the bar. The grinder: Make cleaning the espresso grinder(s) a nightly task. Empty the hopper and wipe it down. As long as buildup isn't out of control a clean damp cloth will do the trick. Don't use a 'scrub pad' on the hopper. Hoppers are made of plexiglass or lexan and will scratch easily. Keep a small shop vac available behind the bar to sweep out the dosing chamber.
The portafilters/ group heads: Once a day, typically at closing, pop the basket out of the portafilter. If buildup isn't heavy a quick scrub with hot water will do the trick. Typically the portafilters and baskets are soaked in hot water and purocaff in a milk steaming pitcher. This will keep the milk pitchers clean as well.
Backflushing the group heads: Unlike the grinder and portafilters forgetting to backflush the group heads can cause maintenance problems. Backflushing cleans all of the oils that build up during normal use. Every machine has different particulars for backflushing so check the user's manual. Just don't forget to backflush!
Changing burrs: It's a simple job and it's cheap. There are of course various methods for determining the frequency for changing burrs. Typically feeling the coffee grounds as they shoot out of the burrs does the trick. When the grounds are feeling warm to the touch, it's time to change the burrs. The heat buildup from dull burrs will also cause significant crema deterioration.

Water quality was a legend, a myth 15 years ago. The information was out there, it was just something that was easy to overlook. With the advances in recent years of coffee quality in general, especially espresso machines; water quality is as important to flavor as grind. The difference being that poor water will not only cause poor tasting espresso, it will wreck your machine. Spend the time and money to get a water test done and be prepared to install the necessary water treatment equipment. If we're your roaster, we'll do a complete water test for free, just send a sample!

Now for the fun stuff! 		 
Here are some pictures that have nothing to do with 'perfect shots', just good riding.
GRIND: Assuming that all other factors remain constant, grind is the one 'variable' to adjusting shot pull times. The constants are: Water quality, espresso machine consistency, temperature mainly, grinder/machine cleanliness, DOSE and TAMP.


Dosing means filling the portafilter with freshly ground espresso. The best method is to keep the dosing hopper empty. Turn on the grinder just prior to dosing. As the espresso is grinding, start dosing espresso into the portafilter. After several doses the portafilter should be just a bit too full. Level off the espresso with your finger. While this technique takes some practice to perfect, it will insure consistent doses.
Tamping means applying pressure to the espresso grounds. Tamping is a matter of style. The definition of a tamp is to apply pressure of at least 25 pounds downforce in order to compact the grounds to provide a uniform density through which water will pass. As the tamp becomes a signature of the individual barista it's difficult to give a definition for a 'perfect tamp'. The basics are: After dosing and swiping, apply downforce, knock the portafilter to loosen grounds from the side, reapply downforce and often finish with a 'spin' of the tamp to polish the top of the espresso.
Now, the grind. If all of the above factors become constants then the only variable to pulling a 'perfect shot' is the grind. Adjusting the grind is simple. All that adjusting the grind consists of is moving the burrs of your grinder closer or further apart to make smaller or larger particles of espresso. The smaller the particle, the slower water will pass through it. The larger the particle the faster the water will pass through it. The best analogy is to compare espresso in the portafilter to rocks in a bucket. If you fill a bucket with rocks and dump water through the bucket, water will pass quickly. If you place sand in a bucket, the water would pass more slowly. Finer grinds mean slower water. 		 


Push the button! Pull the handle! Pull a shot of espresso! Watch the magic flow! What's so special about 'the perfect shot'? It's like learning to ride a bicycle. Once you get it, you just get it. The major factors are that enough espresso was dosed (16-22 grams) through which 1-1.5 ounces of water will pass in 23-28 seconds. That doesn't explain the magic. The magic is in the flavor, though there are obvious visual cues.
This illustrates a 5 second shot. If you look closely at the 1st photo, it looks like a decent shot. Note the 3rd photo; the crema is light in color and obviously weak. Photo 4 is only 30 seconds after the shot pulled. The crema is falling apart. This shot would taste very weak and thin bodied.
This is a 15 second shot. The first 3 photos illustrate that the shot is pretty close to acceptable. Note the 4th photo, the crema is still light and weak.
This is a 'good shot'. It pulled in 24 seconds. Note the appearance of the espresso in photos 1 through 4. Photo 5 demonstrates the appearance of better crema with darker and lighter 'stripes' of crema producing a marbled effect known as 'tiger stripes'. Photo 6 was taken after 5 minutes; there is still a thick head of crema.