MANY WINERY OWNERS have made large fortunes, but few could be called larger than life. The late Jess Jackson earned both the characterization and the billions thanks to his business acumen and his unique personal style. He amassed tens of thousands of acres in five countries, raced some of the most famous thoroughbreds in modern history and created Kendall-Jackson Chardonnay—a wine so successful it's not just a brand, it's a wine archetype.

I first met Mr. Jackson and his wife, Barbara Banke, almost six years ago. Mr. Jackson had stipulated that our meeting should take place at their farm in Kentucky. At the time, Mr. Jackson was nearly as focused on racing as he was on wine. He'd bought a large stable in Lexington and named it "Stonestreet"—the same name as his winery in the northern Alexander Valley of Sonoma County, Calif. (Stonestreet was Mr. Jackson's middle name as well.) The year of our meeting was particularly propitious for Stonestreet stables; their star horse Curlin won the Preakness and the Jockey Gold Cup, and was named the 2007 Horse of the Year.

It was hard not to be impressed by Mr. Jackson: his forthright manner, his restless intellect, his towering stature (put to good use in the old Kendall-Jackson ads, in which he was invariably photographed in front of a mountain—one that he owned, of course). During our time together, he'd spoken of his desire to "clean up the racing industry"—which he deemed "more corrupt than the wine business." This was such an unpopular goal that Mr. Jackson said he received threats of bodily harm and ended up installing a 24-hour guard station at the end of the road to his house in Sonoma.

Ms. Banke, now chairman of Jackson Family Wines, is a very different sort of person—much more matter-of-fact than flamboyant. I was struck anew by their differences when she and I met in Sonoma a few weeks ago. Ms. Banke had just returned from a trip to visit their Italian property Tenuta di Arceno and to attend Vinitaly, the Italian trade fair.

We chatted briefly about the coming Derby and horse racing in general, which Ms. Banke told me "wasn't about making money"—a remark no horseman would ever refute. "Wine is profitable," Ms. Banke added. "Wine is manageable. Even in the worst harvest, we still get something out of it."