Espresso Coffee Machine Parts
Introduction to the Coffee Grinder
Bean Hopper
This is the large, clear, plastic container on top of the grinder. The Hopper holds your espresso beans and feeds the beans into your grinder. |
Adjustment Ring
This grinder component allows you to make changes to the grind size with reference to coarse or fine. The adjustment ring is usually found around the bean hopper. |
Dosing chamber
The doser holds the ground coffee for dosing into the group head |
Introduction to Espresso Equipment
Power Switch
The power switch on most espresso equipment is located on the backsplash of the machine. It is often indicated by a face plate showing the numbers 1 - 0 - 2. The general position for full operation is the 2 position. |
Portafilter / Filter Handle / Group Handle
This is the device coffee is ground into before being placed in the group head. Keep group handles in the group head at all times to keep them warm. The group handle is always inserted left to right. |
Group Head
This is where all the magic takes place. This is where you insert the portafilter when making a coffee shot. |
Sight Glass
This part is located on the front of the machine and indicates the boiler's water level. |
Hot Water Tap
Some call this the Americano wand or tap, but it's simply a hot water tap. |
Pressure Gauge
The pressure gauge is located on the front of the machine. It usually has two needles indicating both boiler pressure and pump operating pressure. This is an important part to be aware of, as it monitors the health of your machine as well as the parameters of your espresso brewing temperatures and pressures. |
Steam Wand
This is the tool used to steam milk. The steam wand is also known as a steam pipe, and it is activated by the steam valve knob. |
Filter Baskets
When you clean the espresso machine you will use a blind filter, which is essentially a filter without a hole to let the liquid out. Leave coffee in the filter basket during service to prevent a metallic taste in the next coffee. |
Knockout Tube
The knockout tube is where you empty the used coffee grounds. Tap the group handle on the bar provided so that the used grounds fall out, then wipe it clean. The knockout tube may be standalone, or it could be part of the espresso machine. |
Preparing to Make Coffee
Before you begin making espresso coffee, you must familiarise yourself with the equipment you will use. If you don't know how to use your equipment properly then you won't be able to make the perfect coffee!
Another important point is that you have to be organised. If you don't have everything ready to go BEFORE you start, you will end up running all over the place and serving cold coffee. The equipment a barista uses to make espresso and the various derivative beverages needs to be absolutely hygienic. It includes:
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The Espresso Machine
An espresso machine extracts and emulsifies the oils in finely ground coffee, resulting in a rich, almost syrupy liquid. The machine dispenses "shots" of 27-30mL into cups for the customer to enjoy. Making an espresso is known as "pulling a shot", as the original espresso machines had a lever which had to be pulled in a controlled manner to dispense the espresso.
The lever was attached to a spring-loaded piston which would apply the pressure required to force the hot water through the coffee grounds. Modern espresso machines use a pump rather than a piston to force the pressurised water through the coffee. This makes it easier to control the pressure and flow of water through the coffee.
The ideal serving temperature of espresso is 60-70°C and modern espresso machines are capable of controlling the temperature to achieve optimal results. On a commercial machine a 27-30mL shot of espresso should take 25-30 seconds to arrive. Variation of grind fineness, tamping pressure used and pump pressure will result in varied extraction times.
Freshly brewed espresso must be served or mixed immediately, because it will begin to cool and deteriorate as it is oxidised by the air. Using pre-heated demitasse or shot glasses will help to preserve the crema and maintain the ideal temperature for drinking.
Barista Tip: Temperature is important to consider when making a variety of coffee styles for an order, as you need to select the correct sequence - for example latte, macchiato and then espresso as you can then serve a high quality product at the right temperature. If you make the espresso first it would go cold by the time you finish the other coffees.
The lever was attached to a spring-loaded piston which would apply the pressure required to force the hot water through the coffee grounds. Modern espresso machines use a pump rather than a piston to force the pressurised water through the coffee. This makes it easier to control the pressure and flow of water through the coffee.
The ideal serving temperature of espresso is 60-70°C and modern espresso machines are capable of controlling the temperature to achieve optimal results. On a commercial machine a 27-30mL shot of espresso should take 25-30 seconds to arrive. Variation of grind fineness, tamping pressure used and pump pressure will result in varied extraction times.
Freshly brewed espresso must be served or mixed immediately, because it will begin to cool and deteriorate as it is oxidised by the air. Using pre-heated demitasse or shot glasses will help to preserve the crema and maintain the ideal temperature for drinking.
Barista Tip: Temperature is important to consider when making a variety of coffee styles for an order, as you need to select the correct sequence - for example latte, macchiato and then espresso as you can then serve a high quality product at the right temperature. If you make the espresso first it would go cold by the time you finish the other coffees.
Coffee Grinder
In order to achieve the best flavour, the coffee must be freshly ground because flavour and aroma deteriorate quickly due to the large surface area of the grind. You must know how to use the grinder correctly because the success of the coffee depends on how the coffee is ground. The settings of the grinder need to be adjusted to achieve exactly the right grind size.
Blade grinders chop the coffee beans into a range of sizes, from dust up to large particles. They are not suitable for use with espresso machines as they do not produce a uniform grind, they heat the beans which affects the flavour and the dust can clog the machine.
Burr grinders work by grinding the coffee beans between 2 rotating abrasive parts, which crush the beans into particles of a uniform size. The distance between the rotating parts can be changed, determining the size of the final grind. Burr grinders do not heat the beans much, which helps to preserve their flavour. This type of grinder releases the coffee's etheric oils so they can be extracted into the drink by the hot water.
Parts of the grinder:
The finer the grind, the more quickly the flavour is released into the water. However, when making espresso, the finer the grind, the longer it takes for the water to penetrate through the coffee cake (or puck).
In order to get the correct amount of flavour in the correct amount of time you will have to fine tune the size of the grind. Try adjusting the grind to a few different settings and see how it affects the final brew. To inspect the grind you can use a range of senses:
Blade grinders chop the coffee beans into a range of sizes, from dust up to large particles. They are not suitable for use with espresso machines as they do not produce a uniform grind, they heat the beans which affects the flavour and the dust can clog the machine.
Burr grinders work by grinding the coffee beans between 2 rotating abrasive parts, which crush the beans into particles of a uniform size. The distance between the rotating parts can be changed, determining the size of the final grind. Burr grinders do not heat the beans much, which helps to preserve their flavour. This type of grinder releases the coffee's etheric oils so they can be extracted into the drink by the hot water.
Parts of the grinder:
- Tamper - used to pack down the ground coffee in the filter basket. To ensure correct extraction use ~20kg of pressure on the tamper to produce a flat, uniform surface
- Dosage chamber - collects the ground coffee. A lever connected to the feed system dispenses a uniform single cup measure of coffee. The amount of ground coffee released per pull is 7g
- Hopper - used to store the quantity of whole-bean coffee necessary for 2-3 hours of service
- Blades - can be flat or conical. The grind size depends on the distance between the blades. Check their condition every 3 months
The finer the grind, the more quickly the flavour is released into the water. However, when making espresso, the finer the grind, the longer it takes for the water to penetrate through the coffee cake (or puck).
In order to get the correct amount of flavour in the correct amount of time you will have to fine tune the size of the grind. Try adjusting the grind to a few different settings and see how it affects the final brew. To inspect the grind you can use a range of senses:
- Look at the grind to see the size and uniformity
- Touch the grind with your fingers
- Smell the grind
- Taste the final brew
Other Coffee Equipment
Jugs
Use the correct size jug for the amount of milk required. You would normally fill the jug approximately 1/3 full before texturing and stretching the milk, so if you are making 2 coffees you would use a jug twice the size than if you were making 1 coffee. In addition to the different sizes, many establishments use coloured tape to identify/code jugs for specific milk, e.g. green for regular milk, blue for skim milk, yellow for soy milk, etc. Jugs are generally made of stainless steel as this has the advantages of durability, easy temperature control and easy cleaning. |
Thermometer
Using milk thermometers helps to achieve a consistent product. This is important because the temperature of the coffee that is served is often a source of complaint from customers. Thermometers will last longer if you keep them clean and in a safe place. Do not place your thermometers in the dishwasher as this will lead to quicker deterioration. To keep your thermometers accurate, you will need to calibrate them at least every 3 months. To calibrate a thermometer, test it at both freezing point and boiling point. To test at boiling point, simply pour boiling water into a heated cup and the thermometer should read 100°C. To test at freezing point, make an ice and water slurry - the thermometer should read 0°C. If the readings are inaccurate, you will need to adjust the milk thermometer. To adjust the thermometer, use a small wrench to twist the nut underneath the thermometer glass. The indicator will move, depending on which way you twist the nut. Repeat the test until the correct temperature is displayed. |
Cups and Glasses
There is a variety of cups and glasses used to serve the various espresso styles. Coffee suppliers often provide cups with their name printed on them so that customers know what type of coffee they are drinking. Businesses that offer takeaway coffees may use a range of disposable coffee cups and lids, or offer to make coffees in customers' own insulated mugs. Many espresso styles are served in simple, white cups, while others have particular cups associated with them:
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Daily Start-up Procedure for Espresso Machines
This procedure takes 15-30 minutes once the machine has warmed up, so it is important to do these steps as soon as you start your shift.
- Lock the group handle on and turn the machine on! It will take 15-20 minutes to warm up to the correct temperature and achieve the desired water pressure.
- Run water through the group handles for 1 minute to warm them up.
- Place coffee from the previous day into the grinder's dosage chamber (this saves the cost of using fresh coffee to warm up the machine).
- Make at least 3 espressos using old grounds to season the group heads and filter baskets.
- Fill the hopper with sufficient beans.
- Empty the dosage chamber of old coffee grounds.
- Grind fresh coffee and make sure that the dosage chambers are covered with coffee.
- Make a fresh espresso. Check the quality by taste, smell and colour of the creme. Make any necessary adjustments.
- Flush the steam wands for 10 seconds to remove any condensation. You are ready to serve coffee!
Pre-Service Check
Before service, check the following points:
Espresso Machine Points of Care:
- Make sure that the milk has been stored in a fridge at 0-4°C
- Pour the required amount of milk into the jug and return the opened carton to the fridge
- Check that the steam wand is perfectly clean and that the holes in the steamer nozzle are not blocked
- Position the nozzle over the drip tray of the coffee machine and gently turn on the steamer tap. Some water is released from the nozzle before the steam appears. This water is condensed steam, and if you do not expel it before texturing your milk, it will end up in the milk jug and dilute the milk. Any water will affect how the milk froths as it is the protein content of the milk that provides the body
- Once the steam is ejected from the nozzle, bring it out from over the drip tray and turn the steam tap on until the steam pressure does not increase any further. Observe the steam jet to ensure that an even pattern of steam is being produced from the holes
- If everything is okay, turn off the steamer tap
Espresso Machine Points of Care:
- Always use warm, dry cups, stacked on the cup warmer 2 cups high
- Keep used coffee in the filter baskets to prevent the espresso from tasting metallic and to keep the baskets warm so you do not serve cold coffee
- Frequently clean the cup holder, steam and water wands in order to avoid the forming of scale and bacteria
- Do not bang the group handle too hard on the knockout tube as this could damage it. Damage will lead to water leakage from the edge of the group head
Preparing the Grinder
Before you start making coffees you must make sure that the grinder is ready to go. Before you start, you should do the following:
- Check that hopper interior is clean and free from moisture
- Ensure the outer areas of the channel are clean and dry
- Fill the estimated amount of beans required for the service period or next 2 hours
- Check the grind setting (should be set to fine/superfine for espresso coffee)
- Run a few grinds through to fill the doser
- In a grinder with a doser, a doser is set to dispense 7g of coffee. This can be checked by weighing if necessary
Testing the Grind
It is very important to check the grind of the coffee to ensure that the best possible quality coffee is being produced. You can check the grind quality by doing some test extractions before service. This will allow you to make any necessary adjustments to the grinder BEFORE you start serving customers.
You should also periodically check the grind during service to ensure that it is still correct, for example if the heat or humidity has changed. If necessary you should adjust the grinder so that the correct quality of coffee is produced. Check the grind again by doing a couple of test extractions.
As you are working you should regularly check and monitor all equipment to make sure it is working correctly and is kept clean and hygienic. If the grinder starts to not work properly, then you should fix the problem if possible, or report it to your supervisor. It is much better to interrupt service for a few minutes and fix a problem, than to continue making inferior coffee for hours.
You should also periodically check the grind during service to ensure that it is still correct, for example if the heat or humidity has changed. If necessary you should adjust the grinder so that the correct quality of coffee is produced. Check the grind again by doing a couple of test extractions.
As you are working you should regularly check and monitor all equipment to make sure it is working correctly and is kept clean and hygienic. If the grinder starts to not work properly, then you should fix the problem if possible, or report it to your supervisor. It is much better to interrupt service for a few minutes and fix a problem, than to continue making inferior coffee for hours.
Extracting the Coffee
- Check that there is enough fresh, ground coffee for the order. Ensure that appropriate cups or glasses are warming on top of the machine.
- Remove old grounds into knockout tube. Dry and clean the filter basket with a cloth or brush.
- Dose the coffee: 1 flick for a single shot, 2 flicks for a double shot.
- Tamp with adequate pressure. Level the coffee by gently tapping the side of the group handle. Brush any loose coffee off the rim of the basket. Tamp again and brush.
- Purge water from the group head for 2 seconds before placing the group handle.
- Brew the coffee:
- For ristretto, use 7g of coffee per shot to produce 15mL in 15-20 seconds
Assessing the Extraction
It is very important to assess the extraction to ensure that the grind is correct and that the machine is working correctly. When assessing the grind you should check the following:
- Aroma - how does the coffee smell? Does it smell correct or is there a slight burnt smell? Is it lacking in aroma?
- Body - how does it look? Is the colour correct or is it too watery? What does it look like when you hold it up to the light? Is the crema the right size and colour?
- Flavour - does the coffee have the right mix of acidity, bitterness and sweetness?
- Volume - was the correct amount of coffee made? Did it take the correct amount of time to brew?
Extraction Faults
While you are making the coffee, monitor the extraction rate to ensure that the correct amount of water flows through the coffee in the correct amount of time. If it is incorrect the coffee will be inferior and you will have to adjust your technique. The following table provides examples of problems with extraction rate.
Extraction too fast = Under-extracted
Extraction too slow = Over-extracted
Coffee grounds in the cup
Extraction perfect
Coffee drips over the sides of the group handle
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Cleaning the Espresso Machine
As part of normal daily routine it is important that the coffee machine is kept clean. Proper cleaning and maintenance of the machine is a key issue in providing excellent quality coffee to customers and in keeping the machine working to optimum capacity. It is essential that any cleaning or maintenance tasks follow all WHS guidelines at all times.
- Follow the manufacturer's instructions for cleaning and sanitising the machine
- Use only the recommended chemical powders for cleaning the group heads, filter baskets and the machine
- Place the chemical powder in the filter basket with a blank screen and secure on the first group head
- Manually run the coffee machine for ~20 seconds then remove the group handle and examine the foamed powder. Repeat the process until the solution looks clean (no coffee staining)
- Back-flush machine with clean water. Repeat this process until the water runs clear
- Remove the steamer rose from the steam wand and check for blockages, clean thoroughly and replace on steam wand. Check steam flow
- Wash the steam wand with detergent and wipe clean, soak the wand in hot water and release a small amount of steam for ~1 minute to loosen any residue
- Turn off the water to the machine at the tap
- Turn the machine off at both the machine and the power point
- Remove the drip tray from the machine and wash it in the sink with detergent, rinse and polish dry
- Flush the waste pipe with clean water to clean and clear it of old coffee grounds. Caution - do not wash or wipe the area of the machine that is exposed when drip tray is removed, live wiring is exposed!
- Replace the drip tray
- Wipe the front, sides, top and splash-back of the machine with sanitising spray and polish with a clean cloth
- De-pressurise the coffee machine by turning on both steam wands