Proper Coffee

5 senses

All 5 senses are involved in appreciating the perfect espresso. The components of the espresso are as follows: (see also under Coffee-Guide)

Aroma

Prior to roasting coffee beans lack any “coffee” aroma
There are over 800 aroma components in a shot of espresso
Aroma is a key indicator of freshness

Crema

Coffee oils that are emulsified in the brewing process form the hallmark espresso crema
Crema colour will indicate the type of beans used
A well-formed crema will support a spoonful of sugar for 4-5 seconds and reform after breaking

Body

Espresso has a distinctive, thick mouthfeel

Grind

In a fine espresso grind, there are 28,000 particles of coffee to every 7g of beans ground
The ideal dose of ground coffee for a single shot is 7-8g

Technology

Brewing temperature of 88-92° C
Water pressure of 9 Bar/132 psi
Measure of single shot = 1-1.2 fl oz
Brewing time of app. 18 seconds

+ plus +

Human interaction
Passion
Skill
Common Sense

For the purposes of being a Barista we will focus on the traditional machine type.

The espresso machine is little more than a water boiler. Various manufacturers distinguish themselves with the number of Groupheads (brewing heads), water outlets and steam wands etc. When buying an espresso machine it’s most important to know how much volume you intend to produce, and take it from there.

  • The key areas of the machine are:
  • The Groupheads (“hotwired” to the boiler) also called handle
  • The Portafilters (this is where the brewing/extraction process really happens)
  • The Boiler (generates steam for milk foaming)
  • The Heat Exchanger (used to heat the coffee brewing water to correct temperature)
  • The Water Pump

The espresso machine uses water heated in a thermal exchange set-up to brew the coffee. At a pressure of 9 Bar/132 psi and a temperature of 88-92° C, this water flows over a compacted wad of finely ground coffee (dosed at 7-8g). The brewing process takes between 22-28 seconds and results in an espresso shot of 1-1.2 fl oz.

Espresso machine cleaning procedure

We all know the creation and care of our coffee drinks is essential; just as important is the care and maintenance of our equipment. Cleaning is not, perhaps, as creative as making espresso drinks, but it is still an essential part of every barman’s job.

The following are guidelines, which must be followed each day to ensure all equipment is in “tip-top” condition:

Group cleaning

Groups should be back flushed at least every three hours. Follow the systematic instructions on the next page.

Espresso cleanser should only be used once a week.

Filters/Handles

Once each shift the handles need to be cleaned. Take a teaspoon and pry the filter away from the handle. You will see a brown, oily build-up on the filter; this build-up causes the coffee to taste bitter. Use a green scouring pad to scrub away the build-up and give some attention to the inside of the handle to remove the lack build-up there.

Steam Wands

These should be cleaned on a regular basis. After you steam/foam milk the wand should e wiped with a clean jay cloth. Never us an abrasive on the steam wand as this will eventually expose the copper underneath the chrome finish and taint the taste of the milk. To clear blocked steam wand tips simply use a paper clip.

Grinder

At closing, the coffee oil build-up in the bean hopper needs to be removed. Simply lock the hopper and pour remaining coffee beans into a clean container or open bag of coffee.

Use soap and water to clean the hopper, rinse thoroughly – THEY ARE NOT DISHWASHER SAFE.

The dosing chamber should be brushed and cleaned each morning. Use a dry bar towel to wipe around the inside.

Getting started – Espresso machine checklist

Freshness of the coffee is critical to good tasting espresso. If you find that the grinder is full of ground coffee from the night before, take a paper filter (used in the pour and serve machine) and dose 10 single pulls of ground espresso. Use this coffee to make your first pot of filter coffee. Repeat this step for a second pot if you find too mush coffee has been pre-ground from last night.

Now, grind fresh espresso. Using the lid from your dosing chamber, pull several measures of ground coffee and pour them back into the dosing chamber thereby mixing the new, fresh coffee with the last of yesterday’s coffee.

Daily operation

  • Back flush each group head with fresh water at least 3 times per shift.
  • Keep handles in the group heads at all times (they must be kept hot).
  • When dosing coffee, remember to pull firmly on the handle to snap back causing a vibration that ensures the full 7 oz have been released.
  • One pull for a single
  • Two pulls for a double
  • Just before shift change, remove the handles from the group head and clean.
  • Separate the basket from the handle; use a green scrubby to clean away all built-up oil and tanning. Rinse, reassemble, and replace the group head.

Espresso: the right cup

The market is full of espresso-sized cups that are triumphs of style over content. What might look great on the counter won’t necessarily give you a perfect espresso. Indeed, many of the cups available will work against you.

The ideal espresso cup needs to be made of good quality, heavy ceramic. This material will hold heat evenly, especially if kept on your espresso machine’s cup warming shelf. From a tactile perspective, quality ceramic is more appealing than fine China or paper.

Choose a cup that has a tulip-like shape. The inside of the cup should curve down towards an almost conical base. This geometry is essential in the formation of a good crema. As the espresso shot pours into the cup, it hits the curved bottom and “churns” with the rest of the flowing coffee. This churning motion enhances the emulsification of coffee oils, which in turn results in a well-formed crema. A flat-bottomed espresso cup simply won’t influence the liquid in this way.

Debate rages over the “correct” way to store your cups on the cup-warming tray of an espresso machine. Upside down or upright? A bit of logic wins the day. By storing your cups upright, the bottom is kept warm (perfect for when the coffee hits it) and the rim is kept cool (so no burnt lips).

Grinder: set up

All grinders work on the same principle: two grinding blades are employed to grind the beans to a set particulate size. One blade is fixed and the other blade rotates at speeds of up to 1200 rpm.

The size of grind depends on the gap between the two grinding blades. This is controlled by an adjustable collar on the grinder unit (see your manufacturer’s manual).

Some rules for grinding:

Coffee beans must always be fresh
Grinding blades should be changed after using around 350kg of coffee (once a year is typical)
The grinder should be kept clean and well serviced

If the espresso shot “runs” too fast or slow it may well be a grinding issue. A basic knowledge of grinder calibration is essential.

Generally speaking, the grind can be varied using the adjustable collar on the grinder unit. As a rule of thumb, one notch of the collar will speed or slow the espresso brew time by 3 seconds.

You can measure the basic quality of the espresso grind before actually brewing a shot. Ideally the ground coffee will have the consistency of fine, damp sand. By taking a sample on a saucer and pinching it, the coffee should hold shape.

Speed problems can also be ascribed to problems with coffee freshness; water pressure; coffee dosing; tamping.

The perfect espresso: steps

In an ideal world, creating the perfect espresso con be split into 12 steps.

1. Unlock the portafilter from the Group (during working hours these should always be locked into position to keep warm)
2. Briefly flush the Group by pressing a brew button
3. Ensure the portafilter is clean by removing any grounds, rinsing with hot water and dry
4. Place the clean, dry portafilter under the grinder dipenser and dose with freshly ground coffee (1 flick of the doser handle for a single shot; 2 flicks for a double)
5. Even out the coffee surface in the portafilter by tapping the sides
6. Tamp the portafiler firmly
7. Tap the sides of the portafilter once more to redisperse the tamped coffee
8. Tamp a secod time with slightly more force – ideally 40psi (gernerally achieved by pushing down firmly with the hand you do not use for writing). As you do this, “twist” the portafilter under the tamp
9. Brush off the tamp to remove any coffee, and also brush the portafilter rim
10. Carefully lock the portafilter into the Group
11. Place the espresso cup under the brew spout(s)
12. Press the appropriate brew button to brew the espresso shot into the cup

Frothed Milk

Compared to espresso, milk has a very simple flavour profile but it is invaluable for adding texture and body to espresso-based drinks. Milk is also useful as a carrier for flavourings and (when foamed) as a platform for garnishes.

  • When we froth (foam) milk using the espresso machine steam wand, we are aiming to increase its volume and change its texture. By a combination of heat and centrifugal force (provided by steam pressure) milk volume can be increased by 100%.
  • Fill a cold milk jug with chilled fresh milk (any milk will foam, higher fat milk foams best) no more than half
  • Flush out the steam wand (nozzle). Put the steam wand into the milk, turn it on and lower the jug until the tip of the steam wand is just below the surface
  • Maintain a distinct “hiss” noise by lowering the milk jug so that the tip of the steam wand is always just below the moving surface of the milk
  • When enough foamed milk has been produced, plunge the steam wand further below the surface of the milk to maintain the essential swirling of milk and foam created by steam pressure. This will also build temperature (to 155°F = 68°C)
  • Use this technique to blend milk and foam into a fluid, textured emulsion
  • It is worth knowing that you ought to aim to increase milk volume by 100% (for Cappuccino) and by around 50% (for Latte)

If the process sounds like a Boeing 747 coming in to land, start all over again!

Proper Coffee
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