Winemaking is a fascinating blend of art, science, and tradition. From the moment the grapes are selected to the final bottling, every step in the process has an impact on the final product. It’s a journey with plenty of room for creativity and expertise.
This article will give you an overview of the winemaking procedure, covering the key stages: growing the grapes, harvesting, crushing, fermentation, clarification, and aging. Along the way, we’ll look at the choices winemakers make and how those choices affect the flavor, aroma, and overall quality of the wine.
Growing and harvesting grapes
Winemaking begins long before grapes are crushed. It starts with selecting the right grape varietal and providing the optimal growing conditions.
Grape varietals and growing conditions
The type of grape you choose depends on the climate and soil where you are. If you’re in a warmer climate, you’ll want to select heat-resistant varietals like Cabernet Sauvignon or Syrah. Grapes also need at least six hours of sunlight each day and well-drained soil that’s rich in organic matter.
You’ll also need to prune the vines in the winter to keep them healthy.
Harvesting for quality
It’s important to harvest grapes at the right time to ensure the quality of the wine. You can measure the sugar content of the grapes with a refractometer, but tasting them is also important. Once grapes are picked, they don’t ripen any further, so timing is key.
Grapes can be harvested by hand or with a machine. Hand-harvesting is more precise, because you can pick only the bunches that are perfectly ripe.
Crushing and Pressing
Crushing and pressing grapes is how winemakers extract the juice, or “must,” which will eventually be fermented into wine.
First, the grapes are crushed to break the skins and release the juice. Often, they’re also destemmed at this stage to remove the stems, which can add unwanted tannins during fermentation.
The pressing techniques are different for red and white wines. For red wine, pressing happens after fermentation. Pressing increases the final volume of the wine by about 15 percent.
Fermentation: Transforming juice into wine
Once you’ve got your grapes crushed, it’s time for the magic to happen: fermentation.
Alcoholic fermentation
This is where yeast comes in. Yeast are the tiny organisms that convert grape juice into wine through the magic of fermentation. The yeast consumes the sugars in the grape juice and spits out alcohol and carbon dioxide as waste products.
Winemakers can use commercial yeast strains that they purchase from suppliers, or they can rely on the wild yeasts that are naturally present in the vineyard and winery. This is known as “spontaneous fermentation.”
Fermentation usually lasts from 5 to 21 days. The amount of alcohol in the finished wine depends on how much sugar was in the grape juice to begin with, as well as the climate where the grapes were grown.
Red wine fermentation techniques
When making red wine, winemakers get to make choices about whether to ferment the juice with the stems included or without them. Including stems can add tannins and sourness to the wine.
To get the most flavor out of the grapes, winemakers use techniques like “pumping over” (pumping juice from the bottom of the tank to the top) and “punching down” (pushing the cap of grape solids that forms at the top of the tank back down into the juice).
Malolactic Fermentation
Malolactic fermentation (MLF) is a second fermentation that winemakers sometimes use. During MLF, bacteria convert malic acid into lactic acid, which gives the wine a smoother, creamier taste.
MLF reduces the wine’s acidity and makes it more complex. Chardonnay is a white wine that commonly goes through malolactic fermentation.
Clarification and Stabilization
At this stage, the goal is to remove any solid particles and impurities that might make the wine cloudy. Winemakers use clarifying agents like casein (milk protein), egg whites, or bentonite clay to help with this.
Two common clarification techniques are:
- Fining: Adding a substance that binds to unwanted particles, making them easier to remove.
- Filtering: Physically removing the remaining particles to create a crystal-clear wine.
Finally, stabilization aims to prevent unwanted changes after the wine is bottled. For example, winemakers try to prevent tartrate crystals from forming in the bottle, which can happen over time.
Aging and bottling
Once fermentation has occurred, the wine is aged to develop more complexity and flavor. The vessel in which the wine is aged plays a key role in the wine’s final profile.
Oak barrels, for example, can impart notes of vanilla and spice. Other winemakers may choose to age their wines in concrete tanks or stainless steel.
After aging, the wine is bottled and labeled. Some wines, such as Rioja and Brunello di Montalcino, benefit from additional aging in the bottle. These wines are often stored for years before they’re released for sale.
Conclusion
From vine to glass, winemaking is a complex and nuanced process. Each step is connected to the others and requires careful attention to detail.
Understanding the winemaking procedure deepens your appreciation for the craft and the choices that winemakers make to create the unique character of every bottle.