Solera

Solera is a fractional aging and blending system used primarily for aging sherry and other fortified wines, though it is also applied to some vinegars, rums and brandies. The term refers to both the method and the cellar arrangement in which casks are organized in horizontal rows.

Typically, several rows of oak casks are arranged in tiers. The bottom row holds the oldest wine (the solera). The rows above (criaderas) hold progressively younger vintages. A portion of wine is regularly drawn from the bottommost cask for bottling. After drawing, the casks are replenished by transferring liquid from the row above, which in turn is replenished from the row above it, up to the top row which receives fresh harvest. This creates a continuous blending of ages, so the individual bottlings are mixtures of vintages.

Origin and use: The solera system originated in Spain and is most associated with the Jerez region, where it developed to maintain consistency in sherry production; records date from the 18th century. The method is now used for sherry wines and is also employed in the aging of Madeira, certain rums, vinegars and some brandies.

Labeling and age: The age of a solera-aged product is not a precise age but an average of the ages of its constituent wines. Labels may refer to the overall age as solera or solera y criadera levels, but the declared age reflects a blended average rather than a single bottle being that many years old.