I’ve written 600 columns in this space and we have never explored the basics of winemaking. So, this week let’s look at the process from field to bottle. Winemaking 101, if you will.
We all know it’s harvest season. In vineyards throughout the Northern Hemisphere, workers are cutting clusters of grapes, either by hand or by machine, from the vines and they’re filling large bins before racing to get them to wineries. There is a romance and excitement to this time of year and, for most people, the perception of harvest season is that all of the action happens out there in the vineyards.
But for winemakers, getting grapes to the crush pad is just the first step in a process. While it is true that the call to pick is the most critical decision made in making great wine, once at the winery, an entire level of decision-making and labor begins anew.
Let’s start by saying that wine, technically, can make itself. Crush a few grapes and leave them be for a while and nature will take its course. Fermentation will take place as the sugars interact with wild yeasts and turn to alcohol, and eventually, voilà, you’ll have wine. That is how the first wines were created. But today there are a wide of range of techniques used to create different wines. Modern winemakers have tools available to them that allow them to make wines ranging from natural wines, which receive minimal intervention, to fully crafted wines that fit a style and vary little from vintage to vintage.
The first thing that happens in the winery, once the clusters arrive, is that they are sorted to get rid of impurities and bogus grapes. Some wineries still use the human eye to pick out grapes that are deemed not worthy. But at major wineries, computer-operated optical sorting machines view each grape individually on a conveyer belt and toss out the rejects. After they have been sorted, the grapes will go through the crusher/de-stemmer, rolling through a machine that pops the grapes and allows the juice to run free, while keeping the skins in with the juice from the grapes.
For white wines, the juice is then “pressed,” separating the wine from the seeds and the skins before fermentation. A bladder press is a device which uses an air-filled bag that inflates and presses the grapes in a cylindrical tube, gently releasing the juice before it is moved to a fermentation tank.
Red wines, however, rely on contact with the skins and stems to absorb color, flavors and tannins so they will sit together, allowing the juice to absorb those properties during fermentation. The must, juice and skins, are transferred to either steel or wood (or occasionally concrete) vats. The sugars in the grapes are naturally converted to carbon dioxide and alcohol.
Winemakers make a whole host of decisions during the fermentation process that will affect the wines they hope to produce. These include things like determining whether to add yeast and what types of yeast they might introduce to stimulate the fermentation process. For red wines, cap management is a critical element. They will choose to either “punch down” the cap of sediment that rises to the top of the tank each day or “pump over” wine from the bottom of the tank to defuse the cap. They will also make decisions on how long to let the process continue.
Once fermentation has reached the desired point, the red wines will be pressed and racked, removing the solid products like seeds and skins, to clarify the juices before aging, or élevage (the term defines the period of time between fermentation and bottling).
Aging brings another set of questions for winemakers. If the wine is to be barrel-aged, then decisions about what kind of oak to use and its origins come into play. Will the wine be better if aged in new or old oak? How about American- or French-derived oak? How about Slovenian? Should the barrels be neutral or will the wines respond better in a “toasted” barrel? Maybe the choice with a white wine is to use no oak at all and to simply let it age within the more neutral confines of a steel tank. Then there are decisions about blending wines that have been aged using a different method or barrel regimen.
Finally, there comes a time when the wine is ready to bottle. For some wines — say a fresh sauvignon blanc — that may be just a few months after the grapes are harvested. For others, like an Italian Barolo Riserva, the wine may sit in-barrel for up to five years, and then in-bottle for another 24 months before it is ready to buy and enjoy.
Pick. Crush. Ferment. Press. Age. Bottle. That’s the process to get wine ready for your glass.