Why does the alcohol content in wines differ..?

Question

I notice that some white wines have a lower content than the red ones..

Answer 1

There are a few different factors that determine how much alcohol is in wine.  One is the type, whites and gentler reds (such as Pinot Noir) have more subtle flavors and tend to have less alcohol  because it could overwhelm the nuances of the wine, while fuller, hardier reds like Cabarnets tend to have a little more because they can stand up to the high alcohol content.  In countries where wine is titled by region rather than grape variety (like France) it can vary accordingly.   Also, simply the different vintners decide how much alcohol will be in the wine to vary themselves from other manufactures.