Extra Grinder Information
Why getting the grind correct is so important to a good cup of coffee.
The grinder is critical to producing the perfect cup of coffee. No matter how good the quality of your coffee is, and how perfectly your espresso machine is operating, if the grind is not set correctly then your coffee will have no flavour, taste or aroma.
Freshly roasted coffee, ground to the proper consistency for your espresso machine is critical to achieving “crema”. Whole beans ground to the right consistency just before brewing provides essential flavour and freshness.
The main function of the grinder is to cut the roasted beans into smaller particles. This process increases the surface contact of the coffee with the hot water enabling the soluble substances to dissolve.
Due to different machines and water pressure there is no precise method of determining the correct degree of grind. Each individual operator needs to set the grind to match all the external factors.
For optimum flavour, coffee needs to be ground so that just the right amount of soluble material is extracted into the finished cup.
The right grind depends on how much time the coffee is going to take to brew.
The briefer the contact time between grounds and water, the finer the grind should be, for example, the espresso machine water is forced through the coffee in a short period of time by pressure created by the machine.
And vice versa: The longer the contact time, the coarser the grind. Such as a plunger, which steeps the grounds in water for around 3-4 minutes to allow the coffee to infuse.
Grind Progression
Plunger - Coarse
Drip Filter - Medium
Domestic Espresso - Coarse Espresso
Commercial Espresso - Fine (for Rancilio Silvia)
Turkish Grind - Very Fine
A Correct Espresso Grind
The correct grind should have the following characteristics:
Fluctuating Weather Conditions
Humidity and moist air can change the grind, the heat will make the coffee sweat and the oil will expand – this can change the grind. As weather can change during the day, so can your grind. It is important to note that any adjustment you make will only need to be slight (one or two notches). With warmer, humid weather the grind will need to be slightly coarser, in cool and dry weather the grind will need to be slightly finer. Do not store your beans in the fridge or freezer.
General roast and freshness of the coffee.
A change of blends will ensure the settings will need to be adjusted. Each coffee has its own unique setting to create the best possible grind for an espresso.
The degree of roast will affect the grind. When ground, lightly roasted coffees tend to be tenacious, pliable and tough. They don’t break apart as easily as the hard, brittle, dark roast beans. These beans become more brittle with moisture loss and are more prone to break into various sized pieces and powder. The grinder might need some adjustment in order to produce the same degree of grind as that obtained with different roast. The darker the roast the coarser the grind, the lighter the roast the finer the grind.
You cannot grind warm freshly roasted beans as they are too soft and will be flattened and crushed, they need to be cooled and cured. As the gases release from the coffee it cures and hardens and you must ensure this happens. On the other end of the scale if your coffee is stale or has been exposed to the elements prior to grinding, a similar effect may occur with the grind as the essential oils dry out and coffee loses its flavour, fragrance and body.
Tamping
Use a tamping tool to press coffee firmly with a slight twisting motion into the cup filter. Firm packing increases the resistance to hot water and allows the maximum amount of oil to be extracted and the wonderful aroma to be released.
The grinder is critical to producing the perfect cup of coffee. No matter how good the quality of your coffee is, and how perfectly your espresso machine is operating, if the grind is not set correctly then your coffee will have no flavour, taste or aroma.
Freshly roasted coffee, ground to the proper consistency for your espresso machine is critical to achieving “crema”. Whole beans ground to the right consistency just before brewing provides essential flavour and freshness.
The main function of the grinder is to cut the roasted beans into smaller particles. This process increases the surface contact of the coffee with the hot water enabling the soluble substances to dissolve.
Due to different machines and water pressure there is no precise method of determining the correct degree of grind. Each individual operator needs to set the grind to match all the external factors.
For optimum flavour, coffee needs to be ground so that just the right amount of soluble material is extracted into the finished cup.
The right grind depends on how much time the coffee is going to take to brew.
The briefer the contact time between grounds and water, the finer the grind should be, for example, the espresso machine water is forced through the coffee in a short period of time by pressure created by the machine.
And vice versa: The longer the contact time, the coarser the grind. Such as a plunger, which steeps the grounds in water for around 3-4 minutes to allow the coffee to infuse.
Grind Progression
Plunger - Coarse
Drip Filter - Medium
Domestic Espresso - Coarse Espresso
Commercial Espresso - Fine (for Rancilio Silvia)
Turkish Grind - Very Fine
A Correct Espresso Grind
The correct grind should have the following characteristics:
- The ground coffee should be fragrant and at room temperature.
- When rubbed in the palm of your hand the grind should feel like castor sugar.
- The coffee should appear extracting from the group head after 4-5 seconds.
- This flow should be even, producing thick, rich, velvet like crema, depending on the roast from a honey to a brown colour.
- The extracted coffee should have a thick crema that remains for approximately 5 minutes or longer.
- The coffee should be opaque and aromatic
Fluctuating Weather Conditions
Humidity and moist air can change the grind, the heat will make the coffee sweat and the oil will expand – this can change the grind. As weather can change during the day, so can your grind. It is important to note that any adjustment you make will only need to be slight (one or two notches). With warmer, humid weather the grind will need to be slightly coarser, in cool and dry weather the grind will need to be slightly finer. Do not store your beans in the fridge or freezer.
General roast and freshness of the coffee.
A change of blends will ensure the settings will need to be adjusted. Each coffee has its own unique setting to create the best possible grind for an espresso.
The degree of roast will affect the grind. When ground, lightly roasted coffees tend to be tenacious, pliable and tough. They don’t break apart as easily as the hard, brittle, dark roast beans. These beans become more brittle with moisture loss and are more prone to break into various sized pieces and powder. The grinder might need some adjustment in order to produce the same degree of grind as that obtained with different roast. The darker the roast the coarser the grind, the lighter the roast the finer the grind.
You cannot grind warm freshly roasted beans as they are too soft and will be flattened and crushed, they need to be cooled and cured. As the gases release from the coffee it cures and hardens and you must ensure this happens. On the other end of the scale if your coffee is stale or has been exposed to the elements prior to grinding, a similar effect may occur with the grind as the essential oils dry out and coffee loses its flavour, fragrance and body.
Tamping
Use a tamping tool to press coffee firmly with a slight twisting motion into the cup filter. Firm packing increases the resistance to hot water and allows the maximum amount of oil to be extracted and the wonderful aroma to be released.