Château Pérac is a more immediately affordable than Saransot being generally made from less concentrated grapes than those reserved for Saransot. Pérac has a shorter lifespan than Saransot.
In 2013 and 2017, there was no Pérac. The best vats are reserved for Saransot, but, for those years, the next-to-best were qualitatively insufficient for Pérac also. In general, Pérac is made up of either grapes from young vines or plots that have produced a little too much and therefore are less concentrated than what is required for Saransot.
Pérac: the goal is to make a good supple, fragrant wine that can be drunk fairly quickly with a medium aging potential.