Espresso: All Things Espresso

Espresso is fussy. It is the pursuit for perfection by a person who is driven by minutiae. This is all kind of funny since the word itself means "express," in the sense that it is prepared upon request, on a moment's notice, on express request, extemporaneously. So where do we find the balance in all of this? How can we expressly deliver the basics of this very involved brewing method? Well, what we can do is address the key variables that will have the greatest impact on your approach to honing your espresso brewing skill.

An Espresso is a small, concentrated coffee beverage, 2.5 ounces or less for a double espresso, served in a demitasse cup. It has both a liquid and a foam element (crema). It is made on a specialized machine that forces hot water through finely ground coffee that has been compacted (tamped), the force of the water being spent in the coffee cake. It takes 20-30 seconds to percolate the water through the coffee cake (or "puck") which is held in a portafilter "coffee handle". It is judged by its appearance, aroma, mouthfeel (body), flavor and aftertaste.

 

A more technical definition of espresso by Ernesto Illy is as follows: "An Italian espresso is a polyphasic beverage prepared from roasted and ground coffee and water alone, constituted by a foam layer with a partiucular "tiger tail" pattern, on top of an emulsion of microscopic oil droplets in an aqueous solution of sugars, acids, protein-like materials, and caffeine, with dispersed gas-bubbles and solids ... The distinguishing sensory characteristics of italian espresso include a rich body, a full fine aroma, and equilibrated bitter-sweet taste with an acidic note, and a pleasant lingering after-taste, exempt from unpleasant flavor defects."

 

A Traditional espresso is:
Volume Ground Coffee Portion Water Temperature Water Pressure Extraction Time
Single Espresso:
1 to 1.25 ounces
29.5 to 37 milliliters
6.5 grams ± 1.5 grams
.23 ounces ± .05 ounce
90 C ± 5 C
194 F ± 9 F
9 ± 2 Bar
130.5 PSI ± 29 PSI
25 ± 5 seconds
Double Espresso:
2 to 2.5 ounces
13 grams ± 2 grams
.46 ounces ± .07 ounce
90 C ± 5 C
194 F ± 9 F
9 ± 2 Bar
130.5 PSI ± 29 PSI
25 ± 5 seconds

You can find out more about espresso standards at Institute Nazionale Espresso Italiano!

Basic Techniques

To make great espresso you need decent espresso brewing equipment. You need a machine capable of delivering water that is not too hot nor too cold, at the correct amount of pressure through a cake of good coffee that is finely, evenly ground and compressed. Steam-powered machines, like the ubiquitous Krups department store models from the '80s and early '90s are not going to cut it. You will need a pump or piston driven espresso machine. At one time that meant buying a hand-pull piston machine, which are still beautiful objects and can still make great espresso! The good news is that electric pump-driven equipment capable of making really good espresso at home is now widely available, starting at about $230 or so (see the Gaggia Espresso). The machine is part of the equation, the coffee is another, and the machine-operator, the Barista, is also key!

 

Warm It Up

Before brewing, the machine and all its parts need to be warmed up. Every part that comes into contact with the coffee should be warm: the brew head of the machine, the coffee handle and portafilter, the cup, and even the tamper ideally! (Per your machine instructions, you are usually running 2 ounces of water through the head to prime the pump and boiler, and you should prime the pump every time you turn the machine on! But at this point, the water isn't hot yet). After the machine is warm, I always run 2 ounces of water through the brew head (with the coffee handle attached) to further warm things up. The first shot is oftentimes a throwaway among purists ... its a test run to see if everything is running right, if the grind is set right for the particular coffee and "degree of roast" that you are using, and to get everything warmed up. Heat up the machine with the coffee handle in the brew head to heat it up, and run a little water through it. Thick porcelain cups (like the Sorrento and Amalfi) that are preheated, or double wall pre-heated stainless steel cups are best. You can put hot water into cups to help preheat them, but dry them out before brewing espresso into them.

Good Grinds, 7 Grams, Consistent Tamping, and Constant Adjustment

You need good, even, fine grind to produce good espresso. Actually, the finest grind will usually not produce the best crema- the water does need to percolate evenly through the compressed cake of coffee. A slightly coarser grind aids in even percolation. Nonetheless, we are still talking about the fine end of the grind range. I prefer a coarser grind and a 40 Lbs of tamping pressure, rather than a finer grind and wimpy tamping to reach my goal of a 25 second shot time. The two are interrelated, and you will find that your barista skill is needed to sense when you adjust them in concert. On top of that, the degree of roast of your coffee is a changing variable, and requires changes in grind. Lighter roasts are less water-permeable, darker roasts allow water to saturate and pass through them easier. So it would make sense that a finer grind would work better with a darker roast (to hold back the water more offsetting the water-permeability) and vis-versa for the lighter roast. But darker roasts compress much easier when tamped. That means the cake is more impermeable to the water. So in fact I have to use a COARSER grind with my dark roast coffees, and I use a FINER grind with my light roast espresso.

You can check your tamp pressure by pulling out the bathroom scale and tamping with the portafilter resting on it to measure how hard you're pushing. The critical thing here is to learn to consistently apply the same amount of pressure. It doesn't matter so much if you apply 25 pounds or 40, so long as you can tune your grind to your tamp, which means you need to tamp about the same amount to every time. In addition to consistent tamp pressure, it's important to insure that you're giving a level tamp.

Okay, now let's add the easy variable: the amount of coffee. Ideally its 7 grams for a single, 14 grams for a double. More and more people are using much higher dosage volumes, somewhere in the range of 18-20 grams for a double and sometimes even more than that. It is best to try to achieve a good extraction with the traditional parameters and then add volume per your personal tastes.

Most people only make doubles with their home machines (single filters taper in to offset the smaller amount of coffee, which sort of violates the espresso purists ethic). You can get pretty close to this using a measure scoop, or by eyeballing the amount you grind into a portafilter before tamping. Or you can use a gram scale ... in fact our Salter Gram scale works pretty well for this, although there are pricier ones on the market better targeted toward the 1-30 gram range. Overall, as a home espresso barista you will need to develop a feel for grind adjustment and tamping pressure. That's why people end up spending so much on a good grinder like the Mazzer, and a nice tamper. But more on these later in The Espresso Pages when I get into the fine grind details.

The Almighty Extraction

So, you have your coffee in the portafilter. You tamped in with the pressure you have deemed appropriate. Then, you wiped off the rim of the filter so you don't compress grinds up into the group head. Now, get out your timer, or look at your watch, and flip that switch! You will learn to hear and see the signs that you have a perfect shot (the right volume of espresso within the alloted time, with that beautiful crema appearance, and that oozing of espresso out of the coffee handle). You will eventually know in the first 5 seconds if its a heavenly shot or a dud. If you are like me, you will probably taste it either way. The ideal drip from an espresso machine is the thinest possible stream, perhaps globby but still held together. Some call this a "mouse tail" stream (but it doesn't happen with all coffees depending on roast and type of coffee). If you are like me, you will stop the shot at 25-28 seconds nomatter what the volume is. If you have 1 oz out of a double, then you call it a Ristretto and you are happy ... if it is 2.5 oz. then you have a true double. If it is 3.5 or 4 ounces then it's a Lungo, and you take a sip and toss it out. But you probably aren't me. On the flip side, if the shot took 10 seconds to get to 2.5 ounces, you have underextraction and you need to make adjustments to tamp and grind. It's fun to taste underextraction (10 seconds) and over extraction (35 seconds), and in fact I like some shots very much at 15 seconds. But it's usually nicer to taste them all at 25 seconds!

In between shots, you need to clean everything out, wipe it off, and dry it too, while not losing the warmth of all the component parts. You want you portafilter and your next cup to be warm but dry. I use both an ample supply of white terry towels and paper towels to clean up. I always run a tad of water out of the brew head and wipe it down with a soft cloth too.

Keeping It Clean

Residual coffee in the handle, brew head -also called the group head, shower screen (the screen screwed into the brew head), and anywhere else in the brew system will turn rancid quickly and taint every espresso you make! Lime scale will build up in the boiler and on the heating elements and eventually the machine won't reach correct brew temperature. Cleaning is critical to making great espresso. Some machines have a 3 Way Valve that releases pressure behind the brew head. These machines usually come with a Blank Filter - a portafilter that snaps into the coffee handle with no holes in it. That means you can put a little coffee cleaner (Cafiza) into it, put it into the brew head, turn on the machine for 30+ seconds, and backflush! If your machine has no 3 Way Valve, no worries. Just keep the coffee handle clean by soaking it in a Cafiza solution, and remove and clean the shower screen every week or two. Use an angled plastic bristled Group Head Brush once a day or more, and you may need a Stainless Steel Bristle Brush to remove compacted coffee. Some machines have brass tanks, some have aluminum. Either way, you can run CleanCaf through the tank which will also address lime scale buildup, or use packets of Urnex Lime Scale Remover. I would not run Cafiza through any tank. After cleaning anything, flush it with water as much as possible. Flush the tank at least twice with water after descaling it.

Water Quality

If the water is bad, the espresso will follow! Some people like espresso brewed with Reverse Osmosis water, softened water, or even distilled water. I don't! I like espresso brewed with good-tasting pure spring water, or good-tasting filtered water. At the shop we simply use our pretty-good Bay area Sierra water, run through an active carbon filter. I think some mineral content in water is best for coffee brewing, but not too minerally. Certainly, taints like chlorine flavor are bad. Certainly, RO or soft water will make a boiler last longer. But I would rather have the espresso taste good, and replace a heating element after 3 or 5 years. If you live in an area where lime scale is a big problem, I would only use bottled water in the espresso machine!

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