From The Business Journal:

Grapes made to grow during cooler months could likely yield a higher quality crop and better wine, according to new research out of California State University, Fresno.

The research explores a method called "crop-forcing" that hasn't been used in the high temperatures of the Valley yet.

By removing buds from newly-set berry clusters on the vine while pruning back shoots and removing leaves and laterals, a second bud will appear several weeks later causing the grapes to ripen later in the growing season when temperatures are cooler.

For more, see: Fresno State explores new grape-growing method