Almost every winery you visit in Franciacorta has some type of display to demonstrate how Franciacorta wines are aged on their lees and how the riddling process is carried out.
But one of the best examples of this can be found at the Ca’ del Bosco winery, where you can actually turn the bottles yourself when you view them. The other thing that sets their display apart is the way it is back-lit, so that you can actually see the lees in the bottle.
The minimum amount of lees aging for a Franciacorta wine is 18 months (for the entry-tier Franciacorta category).
After the second fermentation is completed, the wines will age for at least 18 months on their lees before they are riddled. Four or five weeks before the winemaker plans to disgorge the bottles, she or he will begin riddling them. This work is still often done manually (although now most producers use automated systems to do it). By turning the bottles (manually) in a rack or shaking them uniformly (using a machine), the lees are repeatedly mixed with the wine, thus imparting their aroma and flavor character and even distributing their anti-oxidant property. When the process is complete, the bottles are stored at a downward-facing angle so that the lees gather in the neck of the bottle, thus making it easy to disgorge or purge them from the bottle when the wine is ready to be sealed.
You can see the lees in the photo above. The bottle has just been turned and the lees are flowing through the wine. That’s why the winemaker carries out this process.