Vine to Wine

As you may know, it’s harvest season. It’s time to get those beautiful, juicy grapes off the vine and into the glass. There are a couple of steps for the vine to the glass. First, we have to pick the grapes at just the right time. After that comes destemming, crushing, and pressing. Then we have to start the fermentation process. The wine needs to be clarified, and finally aged and bottled. Once all that stuff is done we can enjoy the fruits of our labor. Easy: one, two, three, right? Well, not quite. If it was that easy everyone would be doing it. Follow me on the grape’s journey from rich, brown earth to your favorite wine glass.

Harvest Time: How do we know when the time is right to pick the grapes? While the grape growing process is certainly up to nature, growers and winemakers add in science and judgement calls, when determining exactly when to harvest. First – we take a good look at the grapes. At the onset of ripening, grapes will change color, which in wine terms is called veraison. With the onset of veraison, color changes; the grapes start taking on sugar and acidity drops. Second – feel the grape. It should be large and firm. Next – cut open the grape and check out the seeds. As the grape ripens the seeds will change from green to brown. Last, but not least – pop one of those lovelies into your mouth. Wie grapes, typically “Vitis Vinifera”, are much sweeter than table grapes. If they’re too tart they definitely need more time. There are some other factors that come into play when deciding when to harvest. If the grapes are just about ready and it’s about to turn rainy, it’s time to bring them in. Heavy rains can cause big problems for ripe grapes. Another factor is the birds and other vertebrates that also really like ripe grapes, so you may have some harvesting competition.

So we have our grapes off the vine. Now what? Take off the stems and start crushing. While it is big fun to throw the grapes in a kiddie pool and invite all your friends over to stomp on them, mechanical pressing is a tad more sanitary, not to mention efficient. In many cases, such as red grapes, the wine maker may choose not to crush at all, which we call whole-berry fermentation. Once the grapes are all smushed into a juicy combination of seeds, skins and solids, the winemaker will use a wine press to separate out the seeds and skins if making white wine. For red wines, we need the phenolics (color, flavor, tannin) from the skins and seeds, so pressing happens after fermentation. In both cases the juicy mixture is referred to as “must”.

The next step is fermentation. This is the most important step in the process as it is the wonderful little yeast, when added to the must, consume the natural grape sugars, glucose and frucrose, to produce alcohol and CO2. The CO2 gets vented off into the atmosphere and we enjoy the alcohol in our glass! Some winemakers choose to allow their wines to ferment naturally, and some will choose commercial yeast strains for more controlled fermentation. This continues until all the sugar is turned into alcohol, anywhere from ten days to a month or more. For sweeter wines, the fermentation is halted before all the sugar is converted.

The next step in the winemaking process is called clarification. This is where all of the dead yeast cells, proteins, and other sediments either drop out of suspension and settle on the bottom of the fermenter. Depending on the type of wine, it is then transferred to a barrel or stainless steel tank for aging.

Aging can be done in the tanks and barrels, and the wine continues to age once it is bottled. This aging process is where the winemaker shows his (or her) flair. Wine aged in stainless steel tanks will taste much different from wine aged in barrels. Different barrels yield different tastes and sensory characteristics in wine, such as French versus American, as well as barrel toasting levels where the insides of the barrels are charred. Some barrels have scoring on the inside to increase the wine’s exposure. Barrels also allow wines to breath, allowing a very small amount of oxygen in and allowing the wine to off-gas some of the byproducts of fermentation.

The last step in the process is bottling. Prior to bottling wine, may be filtered for extra clarification and to prevent any form of microbial contamination before the wine can be consumed. Here again there are a lot of choices for the winemaker such as the style of the bottle, the type of closure such as cork, screwcap, synthetic, capsules and labels. Bottling is such a wonderful culmination of the finished product; a wine in a nice vessel for you to consume.

As you can see there are many factors that affect the taste of the wine. I like to say there are 1000 thoughtful decisions that impact the wine from dirt to bottle. The precise timing of harvest, and the choices made in pressing, fermenting, aging, and bottling all influence the outcome. The combinations and possibilities in making wine are endless; for the winemaker it is a life-long learning process - a very enjoyable life-long learning process. Come celebrate the newest harvest with us. We do wine tastings at Bent Oak Winery every Thursday through Sunday and once the wines have settled in barrels, we may sneak in a barrel tasting or two!