Which factor does NOT affect the extraction time of espresso?

The extraction time of espresso is influenced by several factors, among which dose, tamp, and grind play significant roles. Each of these directly affects how water interacts with the coffee grounds during the brewing process.

The dose refers to the amount of coffee used in the portafilter. A higher dose can lead to a longer extraction time, as more coffee grounds typically require a more extended interaction with water to extract flavors effectively.

Tamping involves compressing the coffee grounds to create a uniform bed for water to flow through. The pressure and evenness of tamping can significantly impact the flow rate of the water, thus influencing the extraction time.

The grind size is crucial as well. Finer grounds increase the surface area exposed to water, leading to faster extraction, while coarser grounds decrease the surface area, resulting in a longer extraction time.

Temperature, while important for the flavor quality and consistency of espresso, does not directly influence the extraction time in the same way as the other factors. It affects the solubility of compounds in the coffee but does not alter how quickly the water passes through the coffee bed. Hence, it is accurate to say that temperature is the factor that does not directly affect extraction time compared to dose, tamp, and grind.