Final answer:
Coffee roast readiness for immediate service depends on whether it's been pre-brewed, not the type of roast. Any roast kept warm after brewing can be served right away. Espresso roast, associated with speed due to the quick espresso brewing process, might be what the question refers to.
Step-by-step explanation:
The question seems to be inquiring about the readiness of different coffee roasts for immediate service, specifically in a context where no additional brewing method, like pour over, is needed. The readiness to serve a coffee roast right away isn't necessarily determined by the type of roast (light, medium, dark, or espresso) but rather by the brewing method used and whether the coffee is already prepared.
For instance, in a cafe environment, any type of roast that has been pre-brewed and is kept in a heated container, such as in an airpot or a thermal carafe, could be served right away.
If the reference is to the typical convenience and speed at which a certain roast is usually served, espresso roast might be the closest answer since espresso is often made on-demand due to its quick brewing process.
However, for clarification, all types of roasts require brewing before they can be served, and none are inherently 'ready to serve' immediately after roasting without being brewed first.