14-16 grammes of coffee ground in such a way that when extracted at 9 bar of pressure using water
heated to 88-92 degrees the resulting beverage takes 22-30 seconds to pour 2fl ozs.

The above numbers are for guidance - some prefer more coffee, and a good extraction can be anywhere between 20-35 seconds, but the pressure and temperature of the water are important.

The espresso should have a thick reddish brown "head" of crema which dissipates slowly in the cup. (The Italian test for crema is to put a spoon or two of sugar on the crema, which should support it for several seconds).

In Italian bars, espresso is usually served with a glass of water, and often with a small liquer - Grappa or Strega for instance.

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How does espresso differ from other coffees and brewing methods?

Espresso has many associated meanings.  Originally, espresso meant a serving of coffee made "espressly for the customer" - that is, brewed at the time of order.  This obviously means a fresher coffee than just pouring a cup from a large jug.  Over time, espresso has also come to be synonymous with the method of brewing (the equipment) and  the coffee (espresso blend).  Although espresso can be made with any beans, it is typically made with a carefully selected blend that will display great flavour in the cup - a balance of taste and aroma that has the necessary properties to produce good crema and particular flavours on the palate.  Descriptions of espresso range from "chocolatey" to "fruity", "spicy" etc, so the blend is important in achieving the taste required.  The degree of roasting plays an important part too, since flavours will vary dramatically from light to dark roasts.  Beans tend to perform better, or produce their characteristic smell and taste, at a particular roast level.  Over-roasting, particularly, tends towards a bitter coffee, under-roasting towards a grassy taste

Espresso is a process, and the process is important, since it differs from other brewing methods in specific ways.  An espresso takes around 22-30 seconds to produce, a much shorter time than other brewing methods such as drip or  french press.  Because the hot water is in contact with the coffee for less time and at a slightly lower temperature, this inhibits the amount of caffeine in the drink (espresso contains less caffeine than regular drip coffee, or even tea).  If the espresso procedure is followed correctly (by trained use of grind and tamp) the resultant beverage is perfectly extracted - neither bitter nor sour and at the correct temperature for drinking.

Because espresso is brewed at high pressure special things happen during and after the extraction.  This method of extracting fresh ground coffee produces the crema that is so specific to the drink.  It is described as a polyphasic colloidal foam. Polyphasic means changing states/phases.  With over 800 aromatic compounds continuously breaking down and combining and the crema releasing its gas and aromas continually, espresso is truly a different experience, one that can remain on the tongue for many hours.
 

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How do I know if it's a good espresso?

That's difficult.  There are many clues to a bad espresso: Little or no crema - Pale or white crema - too much volume.  A chance glimpse  the machine being used can often give clues - a dirty machine can point to sloppy practices that will show in the cup.

However, an espresso may look visually fine - nice crema and the right volume, but still taste wrong. This can be due to many factors: incorrect brewing temperature, dirty machine, insufficient coffee used, stale coffee, wrong sort of coffee.

Although a well trained barista is the key to a good espresso, modern "superauto" machines have taken a lot of the guesswork out of espresso production, and, using automated procedures, are often able to deliver better espresso than that made by an inexperienced barista.  Such machines still rely on some skill - the skill of the technician that sets the machine up and maintains it.
 
 

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What about beans?

Espresso is usually made with a blend, although some single varietals of coffee can make a good espresso.  A traditional Italian espresso may have 5 or more different coffees in the blend, although at least three are usually present.  A nice espresso (that I like) will have a Brazil base another region coffee, such as Indonesian and a small percentage of Robusta (upto 20%).

Of course, there are good and bad Brazils, good and bad Robusta etc, so the quality of the bean is also important.

Robusta is a family of beans, the other being Arabica.  Arabica is usually of higher quality, Robusta is usually used in mass market instant coffee etc.  Whilst there are high grade Robusta coffees, Robusta is more usually used as a filler, as it is cheaper.  The reasons why Robusta is generally cheaper is that the Robusta family is hardier - it can grow in a wider range of conditions than Arabica and is less susceptible to damage through pests, bad handling procedures etc.  Arabica is grown at higher altitudes and is more sensitive.  This doesn't mean, however, that all Arabicas are better than Robusta - a good Robusta can be better than a poor Arabica.

For espresso, Robusta plays a part, since it has good crema properties - providing a lingering crema.

Freshness of beans is important.  Green (unroasted) coffee beans can last years, roasted beans lose their freshness in a much shorter time.  In an ideal world the beans will have been roasted not more than a few weeks before use.

In practice, various technologies are used to lengthen the shelf life of roasted coffee -

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What about the equipment?

Espresso is made using an espresso machine, but you knew that, right?

A modern espresso machine containes a pump, a boiler, and other parts:

Grouphead:  This is where the water is dispensed to make the espresso.

Showerscreen:  where water exits the grouphead.  The showerscreen creates a spray pattern so that the coffee cake is evenly wetted.

Portafilter: The handle that locks into the group, usually with single or double spouts.  This holds the basket.

Portafilter basket:  Removeable perforated insert that holds the coffee, available in single, double and triple (and larger) forms.

There are other parts to a machine, depending on whether it's a home or professional machine:

Automatic Water level: Maintains the correct water level in the boiler (plumbed in machines)

Pressure gauges (for both pump and boiler)

Pressurestat or thermostat (to control the water temperature and pressure)

3-way valve - allows the pressure that builds during the shot to be released, allowing the removal of the portafilter more quickly.

Steam and hot water wands

Switch pads to operate the machine.

There are also different technologies used in espresso machines:

Single boiler machines

Conventional domestic single boiler machines usually have two thermostats - 1 for brewing temperature and another (higher setting) for steaming. This results in a wait whilst changing between brewing and steaming to allow the machine
to equalise at the new temperature.

Double boiler machines

These machines have separate steam and brew boilers and are able to do both tasks at the same time, since each boiler is held at the correct temperature for it's job.

HEX (Heat Exchanger) machines

These operate by running a tube through the main boiler. The tube contains the brew water which is heated indirectly by the water in the main boiler

Lever machines

There are two types of lever machine - manual and spring levers

Manual levers tend to be domestic machines such as the Pavoni, which rely on the strength and skill of the operator to pull the shot.

Spring lever machines are usually commercial (although some domestic models were made) These machines utilise a strong spring to generate the required pressure - the operator compresses the spring when pulling the lever down, the spring creates the pressure when the lever is released (lever machine operation is described in greater detail elsewher on this site).

A good espresso machine must be able to dispense water that is heated to 88-92 at a pressure of 9 bars for the duration of the shot.  Consistency is the achilles heel of espresso - consistent temperature, consistent pressure.

Cheaper espresso machines that rely on steam pressure (not having a pump) will overheat the water and cannot generate the required pressure.

Other "espresso makers" like moka pots etc are used everywhere in Italian homes. They make a strong coffee (sometimes even with a little crema) but do not make espresso.

Examples of good domestic pump machines include the Gaggia range (Baby, Espresso etc), Rancillio Silvia, and the more expensive machines such as Giotto, Livia etc.

Commercial machines are worthwhile investigating if you have the space and drink more than the odd espresso or cappuccino.  They are often available 2nd hand for around the same price of a top end domestic machine, and aren't totally impractical in the home.  Ensure that any 2nd hand machine being contemplated is in good serviceable condition, as spares can be expensive.  Be prepared to at least clean the machine thoroughly and also to undertake some servicing work.  Basic manual or semi-auto machines are best because they have less to go wrong (less expensive circuitry) and they allow control over the output.  Commercial machines often have to be plumbed in, so allow for connection to the water mains, and drainage is required for the drip tray (this can be as basic as a bucket under the drain pipe).

In addition to the above, we need a few other items. We must have a grinder (see separate section). We need a tamper.  This is a utensil used for packing the coffee in the portafilter. Tampers can be made from a multitude of materials - wood, brass, steel etc, but whatever it's made of (and how expensive it is) it must be a close fit in the portafilter. We also need a steaming jug for making milk drinks and optionally, a steaming thermometer. Of course a set of nice espresso demitasse cups and saucers is essential!
 
 

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Cleaning?

It is essential to keep espresso making equipment clean.  Regular cleaning of the portafilter and group (including backflushing or rinsing the group) as well as removing the basket after use for cleaning is an essential part of the espresso routine.

There are proprietory espresso cleaners available to assist in the task of removing coffee oils from your equipment.

Backflushing: Can be performed on machines that employ a 3-way valve.  It Involves the use of a blind filter basket (one with no holes in the bottom) and a suitable espresso detergent such as Puly caf, Urnex etc.

1.  Fill the blind filter with a teaspoon or so of the detergent
2.  Insert the portafilter into the group.
3.  Operate the pump to allow the water to contact the cleaner.
4.  When the pump goes quiet switch pump off
5.  Cleaning froth will exit the 3-way valve
6.  Repeat the above two steps until the cleaning solution runs clear
8.  Remove backflush/blank disc from the portafilter, replacing with the normal basket and flush with plenty of water
9.  Reinsert the portafilter and do a few more flushes with plain water to rinse the area.
9.  Remove the portafilter and turn the pump on and off a few times to flush the grouphead.

IMPORTANT:  Some home machine manufacturers do not recommend backflushing their machines.  It is therefore your responsibility whether you carry out the above process. In any event, if you do backflush, do not labour the pump for more than a few seconds as damage may occur if the pump is constantly under stress.

If your machine doesn't have a 3-way valve you can still clean the grouphead area by doing what is known as a showerhead rinse:

Put the blind insert in the portafilter, or fabricate a semi blind filter insert (a piece of plastic cut to fit the bottom of the coffee basket), a couple of teaspoons of cleaner, then place the portafilter in place loosely, and operate the pump (pull the lever on a lever machine), whilst manually varying the degree of tightness of the portafilter. This gives the grouphead seal and the showerhead a good clean, whilst allowing the pressure to pass through, so as not to damage the grouphead. Repeat the above process with clean water sveral times to flush the area.
 

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What about a grinder?
 

Almost more important than the espresso machine!

A good grinder is essential, in order to grind coffee freshly and at the fineness required for espresso.

There are various grinders available, but we need a burr grinder.  A good quality burr grinder will be able to grind consistently at the fineness required for espresso.

In the consumer price range, suitable grinders are the Gaggia MDF, Rancillio Rocky, Mazzer Mini etc and the Iberital/Innova grinders (these tend to have smaller conical burrsets mounted on plastic carriers, but still seem to be hardwearing enough for domestic use).

Commercial grinders aren't necessarily a waste in the home setting.  They are built to provide many years of service, and in the home environment this translates to a good investment, since they will outlast your espresso machine upgrades.  Suitable grinders include the Rossi RR45, Cunill range, Cimbali Cadet, Mazzer Super Jolly etc.  Spares are available long after these grinders cease to be manufactured, and at surprisingly little cost.  Replacement Burrs (pattern) are available from £15 upwards, so these grinders make a good secondhand purchase.  Plastic parts can be expensive, so ensure any prospective purchase is complete with it's lids etc.

Many commercial grinders come with automatic fill mechanisms.  Although of no use in any but the busiest environment they shouldn't affect a purchasing decision - just operate the grinder manually.

Burr grinders are available with dosers.  These allow the correct amount of coffee to be dispensed.  They are of little use in the home environment, since they need to be partially full to work properly, resulting in stale coffee if not used immediately, but many people prefer them to grinders that grind into a container or just from a chute.  Just switch the grinder on and operate the doser as often as is needed to dispense the coffee.

It is essential to keep the grinder clean by brushing out old grounds etc on a regular basis.  Don't forget that burrs are consumable items - they don't last forever.  Burrs need changing once every few years, depending on usage, and changing them will be much easier if a cleaning regime has been adhered to.  Lack of cleaning the upper burr carrier area will result in coffee oils jamming the mechanism, requiring brute force and extensive time to release.  Regular dismantling of this area allows for cleaning and also inspection of the burrs.  Replace burrs when they feel dull to the touch (they should have sharp leading edges).  Clean the doser and chure area by either brushing or vacuum cleaning the area.

If unused for a while, operate the grinder and discard the small amount of coffee that exits the chute, since this will be stale.

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What about all those other espresso drinks?
 

Espresso is used as a base for other drinks, and espresso itself can be ordered in different ways.  Below are some examples of espresso and it's counterpart drinks.

Ristretto:
A smaller drink, with the grind being adjusted slightly finer to produce less volume. In practice, many bars will just cut the shot short.  (Ristretto means "restricted").

Lungo:
A long espresso, which should have the grind adjusted (slightly coarser) resulting in more volume within the approximate same extraction time.

Americano:
A shot of espresso pulled on top of 5oz or so of hot water, making something similar to a filter coffee.

Cafe Crema:
A different way of producing a longer drink, like an americano, but by adjusting the grind in order to achieve a 4-5fl oz drink in the correct timeframe. For this beverage the grind will be much coarser.

Machiato:
A shot of espresso "stained" with a drop of steamed milk on top (the name means "marked" in italian).

Cappuccino:
Equal thirds espresso, steamed milk and foam.

Latte:
In Italy, this merely means "milk".  Outside Italy, this drink is 1/3 espresso 2/3 steamed milk (although the amount of milk can vary wildly, sometimes resulting in a hot milk drink with a hint of coffee!).

Mocha:
A cappuccino with a spoon of chocolate added

There are national variations - Spain has a drink called a Cortado - like a machiato, but usually a slightly longer drink.
 

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How do I make an espresso?

Assuming you have the correct equipment, proceed as follows:

Ensure your espresso machine is preheated.  Merely switching on and waiting for it to get to pressure is insufficient.  The whole machine needs to be hot, especially the grouphead and portafilter.  Always leave the portafilter in the machine when it's switched on. Try to minimize the time that the portafilter is out of the machine. Preheat your espresso demitasse by filling with hot water.

Grind sufficient coffee to slightly overfill the double basket (approx 14-16 grammes).

Strike off the excess with a crooked finger.

Tamp the coffee firmly (about 10-20lbs of force - practice on your bathroom scales)

"Polish" the cake by tamping with a lighter pressure whilst rotating the tamper through 110 degrees or so.

Remove any stray grounds from the portafilter lip and Insert into the group.

Discard the water in the cup and place cup under the spouts.  (Some recommend drying the cup first).

Switch on the pump and observe.

If the grind is near correct there will be no flow at the start.  If there is an immediate flow then either the grind is too coarse, or the coffee
wasn't tamped correctly, allowing chanelling.  Flow will also be quicker when the machine hasn't been allowed to warm up sufficiently.

After 8-10 seconds or so the flow should start, and the pump should become quieter.

Observe the flow - The stream should be a thick honey-like pour, with dark reddish brown liquid.

If the stream lightens quickly, switch the pump off.

As the stream lightens (after about 25 seconds or so) or you have 2fl oz of espresso after this time, switch the pump off.

Do not let the shot overextract by either running the pump for too long or allowing the stream to lighten.

You should have a nice thick 2 oz espresso!

If the stream lightened quickly or the 2fl oz was dispensed too quickly, adjust the grind a notch finer and start again.

If the pour was too slow (less than 2fl oz), or no liquid came out, adjust the grind one notch coarser and try again.

Espresso is all about containing the variables. Tamp with a consistent pressure. Get your routine consistent so that the only variable left is the grind. Adjust the grind to accomodate the shot timing.

Stale beans will have a big impact on espresso extraction, resulting in a fast pour with little or no crema.

Do not attempt to make espresso with preground beans, since the grind is finely tuned to the machine and the ambient conditions of your kitchen.

Practicing the above will allow you, the operator, to home in on the exact grind and tamp needed to produce that perfect shot.  Even if everything worked as above, you may still end up with a mediocre shot.  After much practicing you will be able to observe the pour with a critical eye and will eventually hit the "sweet spot" - the exact point at which the extraction was perfect.  This may involve very slight changes to the grind etc, but the resulting shot will have all the hallmarks of a great shot - the correct colour crema, perhaps even with "tiger flecking" - small flecks in a stripe pattern on the crema - the sign of a perfect extraction.

Don't forget that the quality and freshness of the beans and grind are paramount.  For evidence of this prove it yourself.  Grind sufficient coffee for a couple of doubles and make the first espresso.  An hour or so later use the remainder of the ground coffee to make another shot and observe the difference - the second shot will have a faster pour with reduced crema.  If this test were to be repeated another hour later the resulting shot would bear no resemblance to the original shot, even though nothing but elapsed time has changed.
 

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How do I steam the milk then?

Steaming can take two forms - making big bubbly froth, or creating dense "microfoam".  Microfoam is a pourable thick froth with extra texture, which I prefer.  Frothing is best learnt with no manufacturers frothing aids or attachments to the wand.  If possible, remove these so that you are left with the straight wand (provided it has a tip with one or more holes present).

To make microfoam we need to do the following:

Start with a cold steaming jug and cold milk from the fridge. Either full fat or semi skimmed (3 or 4%) milk can be used.

(Milk that is fully skimmed, warm, or previously heated won't make good microfoam) Use a jug whose capacity is twice the volume of milk you need - no larger, since the milk may end up only covering the bottom.  The ideal jug for frothing has a wider base and a pouring spout.  Usually made from stainless steel.

Fill the jug to half full or less, depending on the amount of milk you need, but do not fill more than half full as the milk will expand during the process.

Steaming milk is a two process operation - stretching first - Stretching is the action of changing the protein molecules in the milk, which only occurs before the milk reaches a certain temperature, so we need to accomplish this at the beginning.

Start by flushing the wand until steam exits. (Condensed water will be present in the steam wand tube). Then insert the steam wand so that the tip of the wand is barely beneath the surface of the milk.

Turn on the steam wand.  Don't be shy - turn it on!  A steam wand only partially opened will not give sufficient steam to successfully froth the milk, so be brave!  The exception to this is when steaming very small quantities of milk, but even then, it's better to use the right shaped steaming jug (one that allows the milk to be at least 1/3 of the way up the jug), but I accept that blasting a couple of ounces of milk might be messy.  My solution to this is just to steam a sensible amount of milk and use the remainder or give it to the cat!

Keep in mind that as we steam the milk the volume will increase, so we need to gently lower the jug in order that the wand remains just below the surface.  Aim for a sound like a cotton sheet ripping (the sound of air being admitted) - not a big bubbly sound.

As the volume increases (up to 100%) prepare to insert the wand fully. This will stop the stretching phase.  Continue steaming until the correct temperature has been reached.  This is between 140-160F.  A trained barista will hold the bottom of the jug during steaming and when the jug is too hot to hold the correct temperature will have been reached.  You can cheat - buy a milk thermometer if you wish. Another method of determining the temperature is by listening to the noise of the steam wand.  It will lower in pitch as the milk heats.  Stop before it becomes a low rumble, vibrating the jug.

Do not steam above 140F - 160F since the milk will start to scald.

After use, immediately flush the steam wand to stop milk being sucked back into the boiler.  Then wipe the wand to remove any milk.  Leaving this until later makes the job much more difficult.

When do I steam the milk?
If you are preparing a cappuccino or latte you will be preparing a shot of espresso and steaming milk, so one has to be done before the other.  Which you do first is to some extent dependent on the type of machine you have.

I always prepare the shot (but don't always pull it), then steam the milk and finally, pull the shot. This is because I have a large lever machine that can steam and pull shots at the same time.  The espresso would cool quickly if it were prepared first, (since it is a small volume) whereas the milk will stay hot and any crust that develops can be swirled in before pouring.  I can also pull the shot and whilst it is extracting I can then steam the milk.

In a domestic single boiler machine, you will have to wait for the machine to stabilise at the correct temperature for each job, so you can either pull the shot and wait for the machine to get to steaming pressure, or you can steam the milk and then get the machine down to brewing temperature by bleeding some water through the group and admitting fresh, cooler water into the boiler.

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Can I roast beans at home?

How about fresh roasted coffee whenever you want it?  If so, home roasting is for you.  Roasting coffee at home isn't as daunting as it might sound.  Be aware that the smell of roasting beans is not the same as the smell of roasted beans - roasting can produce a lingering smell.  Consider roasting outside.

Equipment can be anything from a £20 popcorn popper to a £400 dedicated home roaster.  In between are the various roasters devised by inventive people, often based on gas bar-b-q grills, hot air guns (paint strippers) etc. Elsewhere on this site there is a pictorial account of popper roasting and also the first attempt at a home made roaster.

Commercially available roasters range from the Hearthware products and the Freshroast to the Alpenrost and the Hottop (£100 - £400)

The differences between the above are batch size and time taken to roast, together with a degree of automation.

To roast at home you will need to source green beans (that is, unroasted, coffee beans). Green beans are available from a variety of online suppliers, and local coffee suppliers will sometimes sell green beans.  Bear in mind that whilst espresso can be made with a single variety, most espresso is made with a blend.

Popper Roasting

In the UK the best popcorn popper suitable for roasting coffee is the Prima PCM001. Do not confuse this with the "Duck"!

In essense, any popcorn popper that has a wattage of at least 1200w and side vents should be able to roast coffee.  Avoid those with bottom vents or lower wattage heaters.

Roasting coffee involves two factors  - temperature and time. Ideally, the roaster should be able to achieve over 400 degrees F, and the roast should ideally take 15 minutes or so.  In the case of the popper the roast is invariably much quicker - in the order of 4-6 minutes, but good results can still be obtained.  Coffee roasted in a popper tends to be "brighter" than that roasted in a more leisurely roaster.  A roast that takes too long because of too cool temperature can result in the coffee baking rather than roasting.

The batch size (amount of beans roasted in one session) in a popper is generally between 50 - 100 grammes.  Changing the batch size affects the roast time - confusingly, smaller batches lengthen the roast time (due to more heat escaping past the beans.

Roasting coffee consists of the following actions:

Roast to 1st crack

Continue to anwhere before the beginning of 2nd crack to past 2nd crack

Cooling as fast as is possible.

Degassing.

1st and 2nd crack are the different stages of roast.  At each point the beans shatter a little bit, some giving off little divots.  Each part of the roast is indicated by a "cracking" sound. 1st crack is a definite cracking sound, whereas 2nd crack is a tighter sound, like static electricity.

Ideally we need to get to first crack fairly fast then slow the roast until the end.  As 2nd crack starts the beans will be getting darker with spots of oil appearing as the roast continues.  You can experiment with slowing the roast after 1st crack by switching the popper on and off in short busts to lengthen the roast time by cooling the air slightly.  It's a matter of personal preference as to how dark you roast, but espresso doesn't favour excessively dark roasts - the flavour will lessen, the darker the roast.  Roast time can also vary with the quality of the power, especially in 110v areas, where a few volts difference in the power supply can affect the roast.  We can use this to our advantage by incorporating a "dimmer" type device to control voltage, but this is requires a more indepth article than this FAQ is inteded to provide.

Since we might want a blend for espresso, you can either pre-blend or post-blend - that is, mix your green beans and roast, or roast each type and blend afterwards. Post-blending is easier since bean varieties roast at different speeds, often resulting in varying degrees of roast.  An exception is a pre-blended green espresso blend, such as Malabar Gold Blend from Josuma Coffee Company, where many bean varieties have already been mixed to create the precise flavour profile of the blend.  Roasting a preblend will result in some beans looking lighter than others, but this is normal.

The steps for a Prima popper are as follows:

Prepare 75 grammes of green beans. Have a colander or two ready (for cooling). Place a container in front of the popper to catch the chaff (chaff is the outer layer of the bean that is shed during roasting) have a stirring implement handy - a chopstick is great.  So is a wooly jumper!

Place most of the beans in the popper and switch on.

Make sure the beans are rotating in the popper.

Add the remainder of the beans (or sufficient that the beans almost stop moving)

Agitate with the chopstick if necessary.

The beans will move faster as they lose weight.

At about 2:30 you should start to hear 1st crack. (Time will vary according to type of popper and amount of beans).

At about 4:00 - 4:30 you should hear the start of 2nd crack.

Smoke maybe apparent at this point.

For a roast suitable for espresso, get ready to remove the beans.

After 30 seconds or so of 2nd crack switch the popper off and quickly transfer the beans to a colander. Agitate the beans in the colander, or transfer from one colander to another to aid rapid cooling.

Once cool (cool enough to handle) transfer the beans to a loose lidded container. The beans will need to degas for 24-48 hours.  After this time the container should be sealed to keep the beans fresh.  By all means try the beans before this time to acquaint yourself with the different tastes that occur during degassing.

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