From Grape to Glass: Harvesting in a Nutshell

With the start of September a distinctive buzz begins to fill the air in Idaho’s wineries. Machines begin to turn, grapes begin to be picked and the subtle hum of fermenting grapes can be heard in the cellar. That is right; it is harvest time in the great state of Idaho. While many of us think about harvest as a fall event, winemakers prep for it year round. Visiting a vineyard during harvest is always a favorite for wine lovers, but do you really know how many steps that grape takes before it becomes the wine you’re drinking now. The process from grape to glass is complex but here is an overview of what a winemaker must do to create your favorite wine.

The first step to planning a harvest is to figure out what you want to produce. Will you make a Viognier this year or stick with the traditional Chardonnay? To help figure this out, much time is spent researching the grapes, the vineyard and the cultural practices of the region. All of this will help a winemaker figure out the best place and way to make their wine. The next step is very important, and unfortunately often skipped, but to ensure that the grapes come out exactly how the winemaker prefers they need to follow the ripening of the grapes and remain in contact with the vineyard. As September approaches, winemakers spend their time out in the vineyards watching the grapes to ensure that the grapes are picked at “optimum ripeness”. This all depends on winemaker’s preference, in general in Idaho white grapes are picked around the beginning of September and red wine grapes will be picked between mid-September and end of October.

Once the grapes are picked the process of winemaking begins. The first step is to remove the juice from the grapes. This is known as crushing and destemming. Once the grapes are crushed they are put into bins to ferment. Fermentation takes approximately a week and is done in order to produce alcohol. During fermentation winemakers have to do either ‘punch downs’ or ‘pump overs’. This is the process of stirring up the fermenting juice in order to get the grape pieces on top and the juice on bottom.

Next comes press, there are a few different types of press machines, but commonly in Idaho you will see a bladder press. The bladder (which is similar to a balloon) fills with hydraulic pressure, which then slowly presses the grapes against the outside of the cylinder as it spins. The juice that falls down without any pressure is known as free run. The more pressure applied the more juice; here is when winemaker preference comes in again. While you want to get enough juice out of the grapes, pressing too hard results in more tannic wines due to the tannins produced from the skins of the grape. This is not a bad thing, but is something that a winemaker will need to watch as they continue to press in order to create the type of wine they desire.

After press the wine is either put into barrels or stainless steel tanks to age. During aging, winemakers have to rack the wine. Racking is the process of taking wine out of one barrel and into the next. They do this in order to get the “junk”, or more specifically, lees out of the wine. They also have to top the barrels, about a bottle worth of wine will evaporate out of a barrel monthly. It is not good to have excess air in the barrels. Winemakers can also do a secondary fermentation, known as malolatic fermentation. This will turn malolatic acid (more similar to a granny smith apple) into lactic acid (such as milk). This is done to decrease the acid level and make the wine smoother. Finally, after aging (which varies greatly depending on the winemaker) the wine is bottled. Typically a wine should sit in bottle for at least 2-6 months before released. This is because the wine will go through what is known as bottle shock. Lastly, the wine is released (commonly wines are released in spring and fall) and the process starts all over again, just in time for the next harvest!