I recently visited Iron Horse Vineyards in Sonoma County, California to see how they make their beautiful, sparkling wine. One of the things that makes sparkling wine so special is the way it is made — it is quite a different process than making other kinds of wine.

The Iron Horse vineyards and winery are operated and owned by the Sterling family. The Sterling’s have worked and lived on this property for a very long time and they care deeply for the land. Iron Horse is run by siblings, Joy and Lawrence Sterling and they were very kind to take me on a tour and actually allow me to work a little bit in the bottling room.

Once the grapes are picked, they go through the traditional process of the first fermentation in tanks. The next step is where the procedure is different; once the wine is taken from the tank, it is put into bottles where yeast and sugar are added. A temporary cork is inserted to seal the bottle and then the wine ages with the yeast in the bottle for a certain number of years. The time that the wine “sits” on the yeast varies depending on lots of factors like the existing sugar content in the grapes. Deciphering all of those factors is the important job of the winemaker.

Once the wine has aged, it is important to remove the yeast and sugar from the bottle. It was very interesting for me to discover that the way they do this is to slightly freeze the wine in the bottle. The bit that freezes first is the old yeast and as that little piece freezes, it rises to the top. One by one, the workers pop out the temporary cork and the pressure from the bubbles pushes out the little frozen bit. They quickly put the bottles onto a machine that adds the “dosage” which is a mixture of sugar syrup and either Chardonnay, Pinot Noir or a combination of both (again, this is where the winemaker works magic). Once the dosage is added, the bottle is sealed with the real cork and then put into bins where the bottles wait to be labeled and then sold. Because the entire aging process is done in the bottle, at the facility, once the bottles are sold, it is the perfect time to drink them. The growers, winemakers and the people who work in the bottling room have done their job and it is time to enjoy!