Max Q is a single point during a rocket's liftoff when the vehicle is under the most stress. When a rocket first takes off, it is going very slow; however the atmosphere is very thick. As a rocket rises, the velocity continues to increase and the atmosphere gets thinner and thinner. However, around 11-14 km up, the vehicle goes through "Max Q" the most stressful point of the flight. Beyond that flight, the atmosphere becomes thinner and thinner so there is less stress on the rocket.
Much like this rocket analogy, our Max Q line comes from The Rocks AVA, which has some of the most stressful vines. Stressed out vines produce some of the best fruit and therefore the best tasting wines.