Q. Is there any way to keep pasta hot for hot service (for example on a buffet-type service)? If so, how long will it hold for without compromising too much of the texture?
There's a reason you don't see a lot of pasta on buffet tables it becomes soft and mushy and turns to glue. You can hold it reasonably well for about 30 minutes, but even then, it will have passed the wonderful al dente point that is the goal with pasta.
To prepare pasta for piecemeal service whether in a food-service setting or at home follow these steps: Use at least a gallon of water per pound of pasta. Add 1-1/2 teaspoons of salt to the water, and bring it to a rapid boil. Add the pasta. As it softens, stir gently to keep the pasta from sticking to itself and to the pan. Continue to stir occasionally as it boils.
Drain the pasta while slightly undercooked. Rinse it briefly in cool water enough to stop the cooking and rinse off the starch, but not enough to cool the pasta. It should still be quite warm. Transfer the pasta to a steam table pan and toss it with a little oil to keep it from sticking.