Espresso extraction

Question 1

What is step one?

Answer 1

Grind the Beans

Using the grinder, grind a dose of coffee.

Question 2

What is step 2?

Answer 2

Measure a dose of coffee

Question 3

A single filter basket generally holds ____ g of ground coffee

A double filter basket generally holds ____ g of ground coffee

NB there are many different filter basket sizes

Answer 3

A single filter basket generally holds 7g of ground coffee

A double filter basket generally holds **14g ** of ground coffee

Question 4

A correct dose of coffee can be measured in any of what three ways:

Answer 4

using scales – use scales to weigh the correct dose

using the dosing chambers in a grinder – most grinders have individual chambers which hold a consistent amount of coffee

sight – fill the filter basket to measure the correct dose (this is the least reliable method)

Question 5

What is step 3?

Answer 5

Tamp the Coffee

Ground coffee must be compacted using a coffee tamper with approximately 18kg of pressure to prepare it for extraction

Question 6

What is step 4?

Answer 6

Check the Pour

Question 7

When pouring espresso, the flow texture should appear ________ ?

Answer 7

Consistent and be the thickness of cooked spaghetti.

Question 8

30ml of espresso should pour in _____ seconds.

Answer 8

30 Seconds

Question 9

Golden rule: 30ml-in-30sec (anywhere between 25-30 seconds is acceptable)

Answer 9

30ml-in-30sec (anywhere between 25-30 seconds is acceptable)

Question 10

If the espresso is running faster or slower than 30ml in 30 seconds the grind will need adjusting.

A grind size that is too fine will result in the coffee pouring out too __________

Answer 10

A grind size that is too fine will result in the coffee pouring out too slowly.

Question 11

If the espresso is running faster or slower than 30ml in 30 seconds the grind will need adjusting.

A grind size that is too coarse will result in the coffee pouring out too _________

Answer 11

A grind size that is too coarse will result in the coffee pouring out too quickly.

Question 12

What is the crema? What should it look like?

Answer 12

The crema is the creamy layer on top of a freshly made espresso. It should be rich and golden in colour.

Question 13

When is the Crema made? What type of foam is it?

Answer 13

Crema is made when air bubbles combine with oils from finely ground coffee. It is a fine foam without big bubbles.

Question 14

During the espresso extraction, when the coffee changes colour from dark to light…. What should occur and what happens if you continue?

Answer 14

During the espresso extraction, when the coffee changes colour from dark to light the pour should be stopped. Continuing beyond this point will bring the impurities of the coffee into the cup.

Question 15

If the espresso is under-extracted, what will the crema look like? and how will it taste?

Answer 15

If the espresso is under-extracted, the crema will be light in colour and thin in appearance. The coffee will taste weak, watery and sour.

Question 16

If the espresso is over-extracted, what will the crema look like? and how will it taste?

Answer 16

If the espresso is over-extracted, the crema will be dark and patchy in appearance. The coffee will taste burnt and bitter.

Question 17

A good pour, will result in the crema being ___________

Answer 17

A good pour, will result in the crema being consistent, rich and golden in colour.

Question 19

What are the four variables that will impact the timing of the espresso pour

Answer 19

Dose – the correct dose of coffee is important

Compaction – 18 kg of downwards pressure should be used to compact the coffee

Particle size of the grind – a finer grind is used in a commercial machine. We’ll teach you how to adjust the grind size in your class.

Humidity – rising and lowering humidity in the air will affect the extraction time of the coffee

Question 20

Coffee is hygroscopic which means it is like a sponge - it will absorb the environment around it.

Therefore, with rising and lowering humidity, coffee will absorb different amounts of moisture and in turn extraction of coffee will be affected.

A good barista will regularly time the extraction and check the spent coffee grounds, making adjustments to allow for the effect of rising and lowering humidity to maintain a _____-_____ second extraction time for a 30ml espresso shot.

Answer 20

Coffee is hygroscopic which means it is like a sponge - it will absorb the environment around it.

Therefore, with rising and lowering humidity, coffee will absorb different amounts of moisture and in turn extraction of coffee will be affected.

A good barista will regularly time the extraction and check the spent coffee grounds, making adjustments to allow for the effect of rising and lowering humidity to maintain a 25-30 second extraction time for a 30ml espresso shot.

Question 21

What should you look for in espresso?

Answer 21

**Timing of the pour **– the espresso pours approximately 30 ml in 25-30 seconds

**Crema **– rich and golden in colour

**Consistency of coffee grounds **– the coffee puck should be firm but moist and in one piece when removed from the group handle

Taste – it’s all in the taste! It should be sweet and full bodied