Not only do Americans not drink much sherry, they don’t know much about how it’s made, either. I certainly didn’t until a few months ago, when I was a guest of Bodegas Osborne in Spain and had the chance to visit their vineyards and cellars in El Puerto de Santa Maria south of Seville. After I saw the indigenous yeast at work fermenting the grape juice and the solera system of blending wines from different vintages, I realized that sherry, like a good loaf of sourdough bread, is the product of unique yeasts and the mixing of old and new to produce something that can never be replicated in any other place or at any other time.
You’re probably familiar with the way sourdough is made using a starter that was developed from indigenous airborne yeasts, flour, and water. Every time a new loaf of bread is made, a piece of starter is used as a leavening agent. Bakers carefully manage their starters, and keep them going for years by feeding them with more flour and water after they are depleted to make bread. I asked my local baker, Margaret Smith of the Twofish Baking Company, how old her starter was and she told me it was having its fifth birthday. Smith feels that using a starter gives her sourdough bread character with an excellent crumb and chewy texture, and that it also imparts flavor to the bread.
Sherry is made using a similar process involving the local flor yeast and the movement of wine through a series of barrels called a solera over a period of many years—even decades. A solera consists of several stacked tiers of interconnected barrels which often constitute a hefty portion of a sherry-maker’s inheritance, since these barrels have been passed down for hundreds of years from generation to generation. As this picture shows, new barrels are almost filled with juice from Palomino grapes, a little air is allowed to enter in carrying the flor when the barrel is not perfectly sealed, and it is placed in the top tier of the solera. As the wines in the solera ages, wine is removed from the bottom tier of barrels for bottling, which causes fresh wine to trickle down from the top of the solera into the next tier of barrels, which displaces their wine into the lower barrels. The uppermost barrel in the solera is topped up with fresh juice, and the process continues.
Some soleras,, like those pictured here in the Osborne cellars, have been kept in continuous use for more than a century—which is considerably older than the Twofish Bakery’s sourdough starter. Most sherry houses can tell you when a solera was first put into use, but they cannot tell you precisely how old the wine is inside any bottle of sherry. It contains drops and trickles of older wine and newer wine, and that’s what gives sherry its timeless qualities and rich character. If you've never tried Fino or Manzanilla sherry, chilled to a crisp coolness and served with some briny olives on a hot summer afternoon, you are missing one of life's great pleasures. Just like a loaf of bread, a glass of sherry has a unique history. And some of that history is included in every sip.