The Sonoma Cheese Factory This building is dedicated to Celso Viviani, an Italian immigrant who came to Sonoma, California in 1910. Celso began making cheese in 1921 and started his cheese making business in 1931. He constructed this building in 1944 and opened the cheese factory in 1945. It was a manufacturing plant and a retail store, as it is today. Celso hand made his jack cheese here in the rear of the building. The business is still operated today by the Viviani family.