A solera consists of four or five rows of barrels
stacked one on top of the other.
The oldest wine is in the bottom barrels and the
youngest is in the top.
Wine is bottled from the bottom barrels which are
topped up from the those in the level above.
Those barrels are topped up from the barrels
above them, and so on.
New wine is added to the top barrels
The new wine gets its flavor from the older wines
and the quality and flavor is maintained. The process takes three years.