"Jess had a very specific plan on how the assets are controlled by the family, going from generation to generation," Hartford said. However, he declined to explain exactly how Jackson and Banke structured the company so it will not be broken apart.
Transferring a wine business to the next generation can be a tricky process, however, and Wine Country is replete with stories about wine fortunes lost to feuding heirs, said Jay Silverstein, an accountant at Moss Adams who has expertise in succession planning.
Children often have varying levels of interest and aptitude for running wineries, and avoiding strife among them is key, he said.
"If you're not careful, tension among owners can lead to a decline business," Silverstein said.
Jackson has been turning over ownership of his vineyards and wineries for years. Silverstein said transferring assets to children and spouses through trusts is a common way for wealthy business owners to not only transition the business to the next generation but lower the estate's tax burden.
Jackson's two children with his first wife, Jane Kendall, are Laura Giron and Jennifer Hartford, who is married to Don Hartford. The company's website lists the sisters as owning La Crema winery in Windsor, the empire's second-largest wine brand and one of its most profitable.
His three children with Banke are Katie Jackson, Julia Jackson and Christopher Jackson.
Katie Jackson, 24, is affiliated with Cambria winery in Santa Maria and works in the communications department at Jackson Family Wines. She has a blog on the website for Cambria, which makes a Katherine's Vineyard chardonnay.
Her younger sister, Julia, also has vineyards on the Central Coast and works in the company's communications department, where she has a blog on the website for Kendall-Jackson winery.
Christopher Jackson, who at 6 feet 4 inches stands even taller than did his robust father, is set to graduate from college this spring and is considering enrolling in graduate school to receive a joint law and business degree.