Corto shots (often synonymous with Ristretto) can be used as the basis for many other drinks but also work quite well drunk straight as an Espresso shot.
Here are the methods and tips on making a good Corto shot.
Use 12 grams of ground coffee per shot.
Grind: Ultra Fine
Method: Extraction with hot water under very high pressure. A fast short extraction is the key here using a similar amount of water as an Espresso shot. Tamp the coffee down firmly to maximise the extraction if an ultra fine grind is not available.
Duration: Extract just 1 to 1.5 ounces per shot under high pressure. Extraction time is the same as per an espresso but uses the same amount of water flowing faster or less water depending on your maker.
Crema should be golden brown with a sweet taste. The shot produced will be a little less bitter than an Espresso shot and have quite a strong body with chocolaty aftertaste.
Serve: In a regular cup and top up with hot water and or milk to make a Cortado, but it can also be used to create a smoother Americano or stronger Latte coffee.