(FruitionSciences) - In this blog we discuss why adapting harvest date to a warming environment is challenging …and why you may not have to trade off sugar concentration to get high color concentration.

Higher sugar concentrations at harvest are often associated with an increase in temperature. This is observed empirically and scientifically in the last decades throughout many wine regions. But, if climate is warming, why not simply harvesting systematically earlier? That way, fruit would be exposed to higher temperatures for a shorter period of time and maybe the amount of sugar would not rise as much?

Why harvesting with a high sugar concentration?

Australian researchers have demonstrated that, even small increases of berry temperatures uncouple the color content and sugar content with red varietals. It also affects other berry sensory traits, like aromas.

To compensate for the delay in color accumulation versus sugar accumulation, winemakers have 2 options:

1. Harvest according to sugar level. It means fruit color will be less than what it could be. Flavor will probably be on the vegetative side. Color incorporation into tannins will also be less.
2. Harvest according to color accumulation. It means harvest decision will track color variations and not so much focus on sugars.