Espresso extraction has many variables and flavor and concentration preferences. This article provides dialing in tips and espresso basics.
Pointers for Espresso Extraction:
1. A good extraction starts with thick, dark brown streams dropping from the portafilter. The streams will become a light caramel color as the shot runs longer.
2. If you are not using a scale to measure your coffee ground and espresso beverage volume, (*ratio and weight recipes outlined below) it’s advised to stop the shot once the stream starts to become completely transparent and thin. At that point in the extraction, you may begin to dilute the shot and introduce an unbalancing volume of bitter and astringent compounds.
3. Generally speaking, unless you are pulling a very lightly roasted coffee, running the shot really long past a 1:2 coffee to liquid espresso ratio or far past a 35-second brew time can tend to dilute the shot. You also may extract too many bitter, dry/astringent compounds. Typically, an espresso shot that starts and ends in a 25-35 second timeframe will yield a balanced and sweet espresso.
*Please note that espresso extraction has many variables and flavor and concentration preferences. It’s also worth mentioning that variables like water temperature, roast level, roast freshness, grind quality, and consistency can play a large part here. The above is an excellent starting point, though!
Dialing In Process:
1. First, pull a test shot. Note the streams’ progression, the weight of the dose, the brewed espresso weight, and the shot time.
2. Taste the shot to check for sweetness and balance if the desired liquid espresso weight is reached within your preferred ratio.
3. If the desired liquid espresso weight is reached too slowly, you might extract more bitter and dry compounds that can unbalance the shot and exhibit over-extracted characteristics. Taste the shot and see what you think. The first step is to grind coarser to decrease the surface area, lessen water restriction through the coffee bed, and speed up the shot.
4. If the desired liquid espresso weight is reached too quickly, your espresso might tend to be a little sour and exhibit under-extracted characteristics. Taste the shot and see what you think. The first step is to grind finer to increase the surface area and water restriction through the coffee bed to slow down the shot.
5. Continue to adjust grind until the shot falls roughly within the parameters above the coffee tastes delicious (sweet and balanced).
A short note on tamping:
A firm (referring to the downward force applied onto the coffee bed), level, and consistent tamp is advised.
**There is some research currently being conducted, by Dr. Samo Smrke, regarding the appropriate Kg of force one needs to apply to the coffee bed went tamping to ensure consistent espresso extraction. The preliminary research suggests that 6 kg of force is generally required to yield consistent extraction.
Sample Espresso Recipes:
- Ristretto: about a 1:1 coffee to beverage ratio
- 18 – 20 grams of coffee
- 18 – 25 grams of liquid espresso
- 25 – 35 Seconds
- Normale: about a 1:2 coffee to beverage ratio
- 18 – 20 grams of coffee
- 34 – 40 grams of liquid espresso
- 25 – 35 Seconds
- Lungo: about a 1:3 coffee to beverage ratio
- 18 – 20 grams of coffee
- 40 + grams of liquid espresso
- 25 – 40 Seconds