Let me tell you exactly how to brew or "pull" a perfect espresso as it's called in barista language. A "barista", the Italian word for a bartender, is a professional operator of an espresso machine.
Obviously, espresso is the basis for any espresso drink, whether you like cappuccinos, mochas or lattes.
The basic items you need are...
- Water
- Coffee
- Espresso Machine
Other things you might consider would be a good coffee grinder and demitasse cups to make it extra fancy. Demitasse means "half cup" in French and generally has the capacity of holding 3 oz. of liquid.
What is Espresso?
Espresso is simply the term for coffee that is finely ground to almost a powdery consistency, then hot water (not boiling) is forced through the grounds under specific pressure for a specific amount of time.
This brewing process is timed so that the flavorful and aromatic oils are extracted from the coffee and not the bitter components. The results are a full-flavored, strong but not bitter, concentrated shot of coffee with golden marbleized foam that covers the top of the espresso called the "crema". Yum... Yum...
Fear not... it's really not that complicated once you have the know-how.
The Water
It very important that you use good clean water, preferably use spring or filtered water free of any chlorine. Not only does filtered or spring water make a better tasting cup of espresso, it's easier on your machine than tap water. Tap water is notorious for leaving hard to clean deposits.
The Coffee
The next thing to consider is the coffee itself. First of all, freshness is of utmost importance. For this reason, preferably buy your coffee from a roaster who will ship within a day or two from the roasting in whole bean form or if you prefer, purchase your coffee pre-ground.
Also, make sure the coffee is of a blend and roast that is especially for espresso.
There are seemingly endless varieties of coffee beans available all the way from light roast to very dark roast and everything in-between.
Let's just simplify the coffee roasting to 3 main styles, light, medium and dark roasts. This is easy to understand because there are also visual clues such a light, medium or dark brown.
The light roasts are not really suitable for espresso, so we are basically left with either medium or dark roast. The dark roasted bean will distinguish itself with an oily and high gloss surface.
Also a dark roast will require a coarser grind than a medium roast for the same extraction.
The grind is probably the most important component of a great shot. It needs to be so fine that it has the consistency of a slightly gritty powder. The time that water is in contact with the grounds is critical.
The coarseness of the grind will determine how fast the water passes through during brewing. The finer the grind, the more time it takes the water to be forced through the grounds because it's more compacted.
The Espresso Machine
Before going into the brewing process, let's just briefly cover a few of the parts of an espresso machine.
Water Tank
The water tank simply holds the water. A large water tank means more espresso with fewer refills. The larger the tank, the less refilling.
Boiler
The main heating unit for water in an espresso machine. It's one of the most important components of the machine.
Thermostat
The thermostat is what controls the water temperature. The proper temperature range of approximately 190 to 195 degrees.
Pump
This is the mechanism which creates the correct amount of pressure, allowing the pistons to operate properly.
Portafilter
The part with a handle and which holds the basket.
Basket
The basket stores the coffee grounds during the brewing process.
Tamper
The tamper is a around flat tool with a short gripping handle that is used to press down on the coffee within the filter basket. This process is referred to as "tamping". The tamper can be made out of plastic, wood, aluminum or stainless steel.
Brewing Espresso
Most commonly, espresso is brewed as either a single or double shot (also called a long shot). This terminology refers to the amount of coffee and water that is used.
The dose is the amount of ground coffee deposited into the portafilter. Most portafilters have a fill line which indicates the proper amount to use.
To brew a 1 oz or single shot of espresso, you will need 7 grams of coffee (about a heaping tablespoon) and pull it in 20-25 seconds.
For a 2 oz or double shot, you'll basically double those quantities to 14 grams of coffee (about two heaping tablespoons) in 20-25 seconds.
But, hey how come it takes the same amount of time to brew a single shot as it does to brew a double?
It's mainly in the filter baskets. For the single shot the basket is shaped differently so the surface area of the filter part is roughly half the size of a double basket. The smaller filter restricts the flow of the espresso so the time it takes to pull a single and double is the same amount of time.
Brewing Temperature:
This is controlled by the espresso machine's thermostat. Normally you don't have to worry about it as good quality machines fall within the proper temperature range of approximately 190 to 195 degrees.
The "in cup" temperature should be around 160 to 165 degrees. The heat loss is simply attributable to the portafilter, the air and the cup.
For a proper "in cup" temperature you should "pull a blank shot". It's simply running 2 ounces of water through the portafilter handle attached to the machine (without the coffee) and into the cup or shot glass to warm everything up.
Pressure
When we're talking about pressure in relation to espresso, there are actually two different things we need to address: tamp pressure and brewing pressure.
Tamp Pressure
This is the amount of pressure used to compact the coffee grounds in the basket in the filter handle (portafilter) prior to brewing.
The general technique for tamping is to apply about 30 pounds of level pressure finishing with a twist to polish the top of the exposed coffee grounds.
Simply use a scale, that measures weights at least up to 30 lbs. such as a bathroom scale to get a good sense of what 30 lbs of pressure feels like. If you place the portafilter handle on a counter top and lean into it with the tamper you will have greater control.
Brewing Pressure
In order to brew a proper espresso, hot water must be forced through the coffee grounds at around 9 bars of pressure - roughly 135 PSI. The pump inside every espresso machine is designed to produce these exact measurements of pressure, so again this is not something to worry about.
Some machines advertise they are able to produce pump pressures of up to 19 bars. However, this doesn't mean that they will then produce better espresso than those of lower pressures.
The machines are designed to not allow any more than about 10 bars. If the pressure begins to exceed that level then a special valve (back pressure relief valve) opens and diverts the water to either the water reservoir or the drip tray. This serves at least 3 functions:
- It protects the pump from excessive pressure buildup
- It lessens the likelihood that the coffee will be over-extracted and
- It prevents the machine from blowing coffee all over the counter top
Coffee Grinder
Some of the espresso machines have built in coffee grinders. If you decide to get a separate grinder, know that there are two types of grinders - burr and blade.
Stay away from blade grinders for espresso making. They cause a number of problems such as dust, heat and inconsistent grind fineness.
Get a good burr grinder.
Extracting the Espresso
First thing you'll need is a clear shot glass with marks for 1 oz and 2 oz.
Fill the portafilter with the ground coffee and tamp the grounds with an even, downward, twisting motion. Then tap the sides of the portafilter causing the coffee on the sides of the portafilter to fall off of the side wall. Tamp again until an even, level and firm compaction is accomplished.
Now brush any coffee on the rim of the portafilter to ensure a snug fit before placing back on machine.
If the grounds are not firm and level, the pressurized water could blast a hole through the grounds and the water would follow the path of least resistance and not pass through all of the grounds evenly. This would over-extract the grounds surrounding the hole(s) and under-extract the other grounds.
The greater the tamp pressure and the finer the coffee grind the greater the resistance. Too little resistance does not allow for sufficient pressure and the resulting beverage is weak with little crema. We call this under extracted coffee. Too much resistance will cause an over extraction; bitter and little crema as well.
With the tamped grounds and the portafilter locked in the espresso machine and the shot glass in place, hit the brew button.
After a couple of seconds, the espresso should slowly start to fill the glass. As it is pouring, the streams should look like the consistency of maple syrup and be about the size of cooked spaghetti.
As the streams of espresso are pouring into the shot glass, observe its appearance.
After about a half an ounce, you should see a layer forming on top that is light brown in color. This layer is called "crema". Crema is a fine celled foam of oils that have the best taste and aromatic properties of the coffee.
The perfect shot of espresso has a layer of crema that is thick, consistent in color and remains intact for at least a couple of minutes before settling.
Poor crema production is usually a sign of under-extraction but can also be caused by stale coffee or a low brewing temperature from not preheating the portafilter.
Another thing to observe during extraction is its color. Initially the color will be light brown in color, but after all of the good oils in the coffee have been extracted; the color will change to a whitish color.
If it takes you less than 20 seconds to brew the espresso, it means you are pulling too fast. The water is passing too easily through the grounds. This is remedied by adjusting your grinder to a finer setting.
On the other hand, if it takes you longer than 25 seconds to brew the espresso, it means you are pulling too slowly. The water is being prevented from going through the grounds at the appropriate rate. You can fix this by adjusting your grinder to a coarser setting.
With a few tries and little experimenting, you should be able to make that great espresso at home with no problemo.
Enjoy!
