Tasting through Robert Mondavi's portfolio continues to reinforce my impression that this winery is undeniably the spiritual and qualitative leader of that sector of the California wine industry dedicated to producing world-class wines. What is so admirable about the entire Mondavi operation is that they continue to push their wines to higher and higher qualitative levels. Their nearly obsessive pursuit of bottling the wines with no manipulation has led to the majority of Mondavi's white wines being bottled without filtration - an extraordinary testament to their commitment to natural wines and superb quality. Mondavi has also inaugurated a line-up of Italian-inspired varietals (Barbera, Sangiovese, Pinot Grigio, Malvasia, and Tocai) in designer bottles. While the quality is good, those products have not yet hit the heights of the firm's other wines. Rest assured, that will change. Current and up-coming releases among the bevy of Sauvignon Blanc wines include a Napa Valley and Reserve cuvee of Fume Blanc, as well as their newest entry in the Sauvignon Blanc sweepstakes, the crisp, barrel-fermented wine from the Stags Leap District. The 1993 Fume Blanc displays wonderfully crisp, stylish, melony fruit, good ripeness, a sense of elegance and grace, and a dry, excellent, delicious finish. All things considered, there is plenty to be excited about at the Robert Mondavi winery. Tel. (800)-MONDAVI; Fax (707) 963-1007.