Following on from last week’s introduction, we’re now going to have a look at how the drink is made.
The production of Sherry is fairly technical so what follows is a very simplified version of events, if you can believe it. If you happen to be writing your thesis on the matter and are after more detail, Julian Jeff’s brilliant “Sherry”, in print since 1961 and now in its 5th edition, is well worth a look (www.sherry.wine).
The Palomino Fino grapes are harvested in early September. Once they’ve been removed from their stems and pressed to separate the liquid from the skins, the resulting juice is fermented quickly at a relatively warm, controlled temperature in stainless steel tanks to produce a neutral, dry base wine with around 11% – 12% alcohol.
Once the fermentation of the must has finished and the nascent wine has been clarified it is fortified with a very, very alcoholic grape brandy mixed with an equal proportion of base wine so as not to “shock” it. The level of alcohol the wine is fortified to depends on the wine that is being made. If the winemaker is looking to make a wine that ages under a layer of yeast (flor) such as a Fino, the base wine is fortified to around 15% alcohol as this is the alcoholic strength at which the flor is happiest. If he or she is after an Oloroso, a wholly oxidative style, the wine is fortified to at least 17% which prevents the flor from growing and therefore the oxygen is free to attack the wine with gay abandon from the start.
We will look at the different styles of bottled Sherry next week but it’s worth mentioning here that they are made from two different styles of base wine that come from the same grape and are made in a similar way. Sherries such as Fino and Amontillado are made from fino base wine (note the small “f” to differentiate it from the bottled version) which in turn is made from grapes from older vines grown on the best Albariza soils. They are pressed gently, if at all, to yield a pure, elegant, free-run juice, low in impurities. The first press, if you like. Olorosos, in contrast, are made from oloroso base wine produced from the fruit of younger vines which grow on heavier, clay based soils and they will be pressed with more force to produce a coarser product with a higher level of impurities, body and astringency. This isn’t to say Olorosos are therefore inherently inferior to Finos and Amontillados, just different. A winemaker certainly wouldn’t be able to make a great Fino from the oloroso juice but a true Oloroso couldn’t be made from the gentle pressings intended for Finos.
Whatever style is being produced, the finished base wine is now ready for ageing and blending…
The Solera System
Now, if you’re a cork dork, this is where it gets interesting. One of the keys to the production of Sherry is the Solera system of maturation and blending. Sherry wasn’t always made this way. It basically came about in order to ensure consistency. This system isn’t unique to Sherry and not all the wines are made this way but the vast majority are and it’s worth examining before looking at the different styles of bottled Sherries next week.
For the sake of clarity examine the two-dimensional pyramid of Sherry casks above, all filled to around 5/6 capacity. The reason for leaving this ullage in barrel will become but in a nutshell it allows the layer of flor to “breathe” and thrive on the styles of Sherry that require it and for sufficient oxygenation to occur when producing wines that are aged oxidatively.