One of life’s true pleasures is the enjoyment of great espresso coffee. For many, the opportunity to indulge at a restaurant or coffee house is sufficient. If you are ready to take the next step and bring the truly rewarding espresso ritual into your home, here are some tips and techniques to help you achieve great success.
Preparing a great cup of espresso is both an “art” and a “science”. Well, not science exactly, you won’t need a degree in physics to learn how to do this well. And the “art” refers more to the challenge you will encounter to prepare a great shot consistently time after time, although there is some poetry to all of this.
Actually, to be fare, the prefect shot doesn’t happen all that often. Even the finest baristas are not capable of producing a nirvana espresso result each and every time. Chances are, you may not have even experienced a truly great shot of espresso. It doesn’t happen as readily as you think. Even the best and most experienced are sufficiently humbled by the elusive essence of a perfect shot.
But don’t be intimidated or discouraged. With a little practice and some knowledge of what to look for, you can definitely become very proficient at making great espresso. And that is more than half the fun! Every so often, when the stars align, a stream of dark rust-red liquid emerges from your espresso machine and the perfect crema, just right in color and consistency, forms at the top of the pour right from the start. The sublime taste of the black nectar and the beautiful lingering finish that remains on your palette confirms the truth – you have produced a great shot of espresso! And that makes it all worthwhile!
The Equipment
You need the right equipment to make good espresso. The inexpensive steam-powered machines that were popular in the 1980’s and 90’s are not going to get the job done. To produce the necessary amount of pressure, either an electric pump driven or hand powered piston driven machine is required.
At one time, a hand-pull piston machine was the only option available. While these are certainly beautiful works of art and can definitely make great espresso, they take more skill that the more modern electric-pump designs. There is a big range in price that you can pay for espresso machines, and you can spend upwards of $3500 for some of the more fancy, top of the line commercial units.
The good news is that respectable machines that are capable of producing great espresso in the home start in the low to mid $200 range. Gaggia, the original inventor of the modern pump-driven machines, offers an entry-level home unit for around $200. The “Gaggia Espresso” model is a no frills machine equipped with the essential basics necessary to make good espresso, including a pump that produces 16+ bars of pressure, a high performance boiler, and a full-size portafilter handle capable of making true 2 oz doubles.
The more expensive units offer additional features, options and premium materials that can provide more control and flexibility, some of which are truly a thing of beauty to display on your counter. The commercial units generally provide more capacity including additional group heads for making multiple shots at the same time. These commercial machines are more suitable for a restaurant or commercial establishment.
Types of Espresso Machines
- Manual or Piston machines – these are the earlier machines that preceded the more modern electric pump designs. The piston machines are still very popular today. They take a little extra work to pull the piston by hand. This gives the operator more control over how much pressure is applied during extraction. This can take a lot of practice to develop a consistent technique.
Being able to vary the amount of pressure is not actually all that critical to producing good espresso. The ideal amount of pressure is around 9 bars. Pressure below 9 bars is not sufficient and more pressure than 9 bars doesn’t produce better espresso. The semi-automatic, automatic and super-automatic machines using an electric pump all generate the optimum amount of pressure automatically making the hand-pull piston machines somewhat obsolete.
There are some aficionados, however, that contend that these manual piston machines in the hands of a true artist can produce the best shots of espresso. La Pavoni and Gaggia continue to produce these beautiful machines today.
- Semi-Automatic machines – these are the most popular type of machines for the home and they are an excellent choice for the majority of users. The semi-automation machines use an electric pump to consistently and evenly produce the appropriate amount of pressure.
The user fills the portafilter basket with ground coffee, tamps to compact the bed of coffee, inserts the portafilter handle, and presses the brew switch to start the extraction. After 25 seconds or so, the switch is turned off resulting in a cup of espresso.
Semi-automatics range in price from $500 to $1800 depending on features and quality.
- Automatic machines – similar to semi-automatics, the automatic espresso machine adds the additional feature of controlling the volume of water that is dispensed through the group head and portafilter. As a matter of convenience, the automatic machine can be programmed to run a certain amount of water through the portafilter during extraction and then stop.
This may be a convenience for a busy barista in a commercial establishment, but the additional capability does not necessarily produce a better espresso result. For the home user, this feature is generally not worth the additional cost over a semi-automatic machine.
- Super-Automatic machines – automatics are often confused with super-automatics. Above and beyond automatics, which add a water dispensing and control feature, the super automatics also do the grinding, tamping and extraction all at the touch of a button.
Super-automatics have the same essential components as the semi-automatics with the addition of an internal brewing system and a high-quality burr grinder all built in. All of these components are coordinated with the help of an onboard computer that enables amazing one-touch espresso coffee as well as the associated cappuccino and latte beverages.
Super-automatics are the most expensive machines and typically range from $500 to $3500 depending on features, capabilities, and quality.
Equipment Terminology
Today’s modern electric pump driven designs come with a wide range of features and capabilities, but they all share the same basic underlying functional and mechanical design and technology. It is helpful to understand some of the equipment terminology common to most of these machines.
- Boiler – all machines have a boiler that typically employs one or more electric heating elements to heat the water. A larger boiler will be able to hold and heat more water at one time which makes it more convenient to produce successive shots of espresso without having to wait for more water to heat up. The boiler heats the water to the ideal temperature between 190 and 196 degrees F (95C).
- Pump – the electric pump forces the heated water through the bed of ground coffee at the ideal pressure of 8 to 9 bars or approximately 135 PSI. The modern machines equipped with an electric pump make it a little easier to consistently produce and deliver the right amount of pressure than the earlier hand-pulled piston devices.
- Piston – earlier models before the electric pump was employed used a hand-pulled piston to create and deliver the pressure to push the hot water through the bed of ground coffee.
A long lever, similar to a slot machine, created the leverage necessary to produce the sufficient amount of pressure. A hand-pulled piston design puts more control in the hands of the operator, but takes a fair amount of practice and technique to consistently operate the machine. The “La Pavoni” espresso machines are the classic example of beautifully crafted hand-pulled piston devices.
- Group Head – also referred to as the brew head, this is the receptacle on the machine that the removable portafilter or group handle attaches to. The hot water, under pressure, flows through the group head as it is forced through the packed layer of ground coffee held in the attached portafilter.
Smaller machines will typically have only one group head. Larger commercial machines will have two or three group heads and can produce more shots of espresso per hour, which is necessary to keep up with the customer demand in a busy establishment. A better espresso machine will heat the group head and keep it at a consistent temperature throughout the brewing process. This generally improves the quality of the espresso result.
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Portafilter – also referred to as the group handle, is the assembly of the handle, filter basket and puring spout.The portafilter basket holds the packed layer of ground coffee through which the hot water is pushed under pressure. The portafilter easily attaches and detaches from the group head.
In the manual, semi-automatic and automatic machines, the portafilter is removed from the group head, the proper quantity of ground coffee is packed into the filter basket using a tamp, and then the portafilter is attached back onto the group head ready for brewing. Once the shot of espresso is extracted, the portfilter is removed and the expended coffee grounds are discarded.
- Tamp – a tamper is used to press and compact a loose bed of finely ground coffee in preparation for brewing espresso. The bed of coffee is tamped into a compact layer in the portafilter basket using between 30 and 50 pounds of pressure.
To determine what 30 pounds of pressure feels like, put your bathroom scale on the counter, put your portafilter handle on the scale, and press down with the tamper while watching the scales dial. A good quality tamper is a useful tool to have. Heavier duty tampers are available made out of solid stainless steel construction.
For best results, portafilter baskets come in two sizes. One for single shots that holds about 7 grams of ground coffee, and a slightly larger filter basket for double shots that holds about 14 grams of ground coffee. A good quality portafilter is has a solid heavier weight which will retain the heat better during operation.
The Technique
Espresso is produced by pushing hot water (not boiling, but close – about 195F) at high pressure (at least 9 bars or about 135 PSI) through a bed of finely ground and compacted coffee. A single shot is about 1 to 1.5 ounces of liquid and is made using about 7 grams of ground coffee. A double shot is between 2 and 2.5 ounces of liquid and uses about double or 14 grams of ground coffee. When extracted properly, the result is topped with a dark golden cream called “crema”.
- Always start with fresh roasted beans. The darker roasts are generally more suitable for making espresso.
- Always grind your beans just before you are ready to use.
- Always use the freshest water possible.
- Always keep your equipment clean. Use the appropriate cleaning agents available to remove scale and sediment buildup inside the machine.
- Before brewing, the machine and all of its parts that come in contact with the coffee need to be warmed up. This includes the brew head, the portafilter, and the cup. You can put hot water in your cups to keep them warm, but be sure to dry them just before use.
- Per your machine’s instructions, you want to run at least 2 ounces of water through the brew head to prime the pump and boiler. This should be done every time you turn on the machine. At this point, the water isn’t hot yet.
- After the boiler heats the water sufficiently, run another 2 ounces of hot water through the brew head to further heat things up. Temperature is critical to producing good espresso.
- The first shot is often a throw away just to be sure things are working right. Test to be sure the grind is right for the degree of roast you are working with.
- You want an even, consistent grind to produce good espresso. A good quality burr grinder is a must to control the grind. Espresso is typically made with a very fine grind, however, this is where you need to be flexible and experiment a little. The hot water does need to percolate evenly through the compressed layer of coffee to produce the best crema. A slightly coarser grind will enable better percolation. But all grind levels that you will use for making espresso are at the finer grind end of the range.
- Dose enough espresso into the portafilter so that it is a little 'too full'. For a single shot, start with 7 grams of ground coffee and 14 grams for a double shot. Skim the excess coffee off the top so that it is level with the rim of the portafilter basket. Tamp evenly with about 25-50 pounds of pressure, depending on the grind level, to compress the cake of coffee evenly. Tamp with more pressure (40-50 pounds) for a coarser grind level, and with less pressure (25-30 pounds) for a finer grind level.
- Of the variables you are working with, extraction time, grind level and tamping pressure, the goal is to always aim for a finished double shot extraction in 23 to 28 seconds. In other words, don’t compensate for an under or over extraction by extending or reducing the extraction time. The ideal extraction time is 23 to 28 seconds. If the extraction is taking longer than 28 seconds, then reduce the tamping pressure or increase the coarseness of the grind. If the extraction is running too fast and finishes in less than 23 seconds, then increase the tamping pressure or increase the fineness of the grind.
- To further control consistency, once you have established the proper tamping pressure for the beans and style of roast that you are using, narrow the variable that you adjust to just the grind level. Keeping the tamping pressure constant, and always aiming for a 23 to 28 second extraction, adjust the grind coarser if the extraction is taking longer than 28 seconds. Go the other direction and adjust the grind finer if the extraction is taking less than 23 seconds. Don’t adjust the dose amount or the tamp pressure to compensate for the extraction time.
- The visual cue that you want to watch for during extraction is the formation of the crema. The espresso should ooze out of the portafilter at about the consistency of warm honey. The flowing liquid should be dark rust-red in color.
- If the crema is a very light tan/yellow color, and the extraction took under 20 seconds, this is an indication of underextraction. Increase the extraction time by adjusting for a finer grind level or tamp with more pressure. Be sure you used enough coffee.
- Symptoms of overextraction include a dark crema color with a lighter tan spot in the middle, ten or more seconds for the first drip to emerge from the portafilter, the liquid coming out in drops and never establishing a stream, and extractions times that exceed 30 seconds. Adjust for a coarser grind level or tamp with less pressure. Also be sure that you didn’t use too much coffee.
- Another symptom of overextraction is indicated when the crema color starts off right, but then the crema visibly drops ¼ inch or more in the cup within one minute. The crema may also appear too pale in color, and you may see large, unstable bubbles at the surface. This might be a combination of shorter extraction time (adjust the grind and tamp pressure), or too light of a roast. Robusta beans will also produce a less persistent crema.
- The ideal crema has a rich dark color with a more compact foam. You may see darker striations producing a “tiger skin” effect. Perfect!
