In this article, I will briefly describe how to making wine from grapes. Winemaking is the intentional transformation of grape juice into wine through fermentation. The job of a winemaker the way I see it is to choreograph the creation of the wine in the bottle from the time you choose a vineyard to determine when it’s picked. To look at the whole vision of what you want from a particular vineyard and make that happen both in the vineyard and the winery. Viticulture and winemaking are inextricably linked. But we can consider the winemaking process as beginning with the decision of when to pick.
The First Step in Making Wine from Grapes – the Decision to Pick
The decision to pick is really really important. That’s probably the most critical part of the whole winemaking process. Factors in deciding when to pick include the amount of sugar and acid in the grapes. In pending weather and the availability of tanks based in the winery. Approaches to harvesting vary. But the primary goal is to ensure that the fruit is kept cool and intact and arrives quickly to the winery. So we get started picking grapes early in the morning. Everything’s hand-harvested into small quarter ton log boxes. We’ll bring them into the winery, weigh them, and then put them into a cold room. At that point, we’ll begin processing.
The Second Step in Making Wine from Grapes – Sorting
Sorting is done by hand or mechanically using equipment designed to remove unwanted material. We take the quarter ton bin we’ll dump it onto a table, we’ll go through and have four to six people hand inspecting the clusters. Then we distend the fruit. We may choose to leave some as the whole cluster which will then dump into the tank. For Pinot Noir, we begin the descending process, and then we go through we individually sort the berries.
The Third Step in Making Wine from Grapes – Crushing, Destemming
For red wines, winemakers must decide whether to destem grapes or ferment the bunches as whole clusters and whether or not to crush the berries deliberately. We aim for the minimal crushing of the berries. Having whole berries, we get a slight carbonic maceration effect. Where we’re actually having the berries break down and release specific strawberry and grassy hay flavors that are really pretty in the wine. When I’m making red wine, it’s very much variety specific. Pinot noir and Zinfandel and both I include some whole clusters because I want a very long extended fermentation time and that’s a tool to attain that. Syrah and Cabernet Sauvignon I tend to destem them a hundred percent.
There is no single right way to make wine. To outstanding producers just as often come to opposite conclusions regarding any individual decision. The key to quality winemaking lies an experienced intuition and an understanding of how the complex interaction of hundreds of choices can lead to the desired result.
The Fourth Step in Making Wine from Grapes – Pressing
The fundamental difference between red winemaking and white winemaking is that with white wines the juice is separated from the skins and the seeds before fermentation. For white wines, a bladder or pneumatic press is often used. It’s a membrane that inflates from one side of this big tube like a can pressing the grapes up against a channel screen, and then the juice comes out of the press. White grapes can be the whole bunch pressed, or they can be crushed or de-stemmed before pressing. We don’t like a lot of phenolic extraction in white wines. So you go directly to a press. You press very gently, and you’ll separate the juice from the skins as quickly as possible. If your stylistic preference is for wine for a little more body and flavor, you might destem it leave it on the skins for a while. Anywhere from a few hours to a day or more to extract things from the skins.
For Rose red grapes may go directly to the press and be handled like white wine. Alternatively, Rose can be made from Saignee or juice is drawn off a tank of red grape must after a short maceration.
By definition red wine is made by fermenting with the skins and the seeds present. All of the color in wine comes from the skins the tannins. The spice compounds come from the skins and the seeds. So with red fermentation, you ferment first and press later.
We’ll do that with a basket press. So it’s a small basket press with a single plunger and basically, give them a little squeeze and juice comes out. The length of skin contact before pressing a red wine depends on grape variety fruit quality and intended wine style. With mountain Cabernet tannin is a big factor in our wines so our grapes come in with a lot of tannins a lot of intensity and the time that they spend on the skins is where all of that flavor comes into the wine. So that “pressing” decision is really really crucial.
Age worthy wines made from healthy grapes often spend more time on the skins. While lighter styles of wine may be pressed earlier.
The Fifth Step in Making Wine from Grapes – Fermenting
Once the fruit is processed, the juice or must is transferred to fermentation vessels which come in a variety of sizes. It may be made of stainless steel wood or concrete.
In the case of white wines are in use exclusively barrels of 225 liters from French oak. For Red’s, we have two different techniques. We can use stainless steel, open on top, or we have some open wood barrels as well.
The size and material of the vessel impact the temperature of fermentation. Many modern tanks are equipped with cooling jackets to provide more control.
In primary fermentation, sugar is converted to carbon dioxide and alcohol. Winemakers track its progress by measuring the Brix level or density of the must. In general the amount of alcohol there is about 0.6 times the level of sugar that came into the winery. So if you come in at 24 degrees Brix, they’re gonna be at a 14 and a half percent alcohol wine.
Yeast can come from a variety of stores since you can buy cultured yeast which had been selected from a fermentation where somebody liked the attributes and propagated and made it available. Or you can rely on the ambient yeast in a winery. Fermentation is typically carried out by the wine yeast Saccharomyces which is adapted to the conditions of high sugar and alcohol. Yeast requires sufficient nutrients and oxygen to thrive. Otherwise stuck fermentations or reductive aromas can occur. Before fermentation, I always have a full juice panel run by a local lab which gives me the all the organic acids the nutrients number of other things I like to look at we’re not directed by numbers, but they give you information it’s valuable.
Chemical analysis of the juice exposes deficiencies that can be supplemented by nutrient and acid additions. Fermentation produces heat, and the range of temperatures throughout the process can impact the flavors of the resulting line. With red grapes, you really want to get a lot of heat early in the fermentation. That’s how you extract color and tannin into the wines. Some people prefer lower fermentation temperatures to extend the fermentation or to keep the wines more on the fruity side. While red wine fermentations reach peak temperatures in the 80s or low 90s Fahrenheit. White wine fermentation is cooler. Especially in the case of aromatic wines. The physical contact of juice and skins is key to extraction. For red wines, this is manipulated through cap management.
As the yeast start to convert the sugar into alcohol, the juice is released from the grapes, and all the skins are lifted up to the top of the tank by the carbon dioxide that’s being produced. So one thing that we want to do is we want to come in and mix the cap to regulate the amount of temperature that’s built up in the tank. During the fermentation, the tank is typically mixed one to three times per day. With practices adapted to vintage and grape variety. You can do that with a pump over where you’re actually pumping the juice from the bottom of the tank and then gently wetting the cap on the top. You can also do it with a punch down where you’re submerging the cap down into the juice, and you’ll get more or less extraction depending on how you choose to manage your cap.
Once fermentation is complete the new wine is drained off of the skins. This free run wine is often higher quality than the wine obtained from pressing the skins. There’s a secondary fermentation that some people do some people don’t particularly in white wines called malolactic fermentation. What is malolactic fermentation? It’s the conversion of malic acid to lactic acid with malolactic bacteria. There are stylistic reasons for doing it with some white wine such as chardonnay because you want the reduction acidity or you’re looking for the diacetyl buttery character can impart. But primarily it’s a stability tool.
For aromatic white wines, varietal flavors are often preserved by preventing secondary fermentation. Through low-temperature sulfur additions or sterile filtration.
The Sixth Step in Making Wine from Grapes – Maturation
A lavage is a term that we use for the period after fermentation before the wine is bottled. Generally, for red wines and for barrel fermented white wines it’s the time that they spend in the barrel where they might be stirred, racked, topped. All those things that we can do in the barrel.
Depending on wine style Ella wash can last anywhere from a few months to several years.
Historically, barrels were just a vessel allows wine to mature, and that one person can handle a barrel. That’s why 50 to 70 gallons tend to be the size range in most areas in the world. But it’s a convenient aging container. The proportion of new oak toast level and origin of the wood all impact the flavor imparted by the barrel. But even an older barrel that has no flavor at all of the wood anymore has a great effect on the wine.
We have to mention the stirring as a subphase in the process of making wine from grapes. Stirring increases contact with the leads which are yeast cells and other solids that have settled from the wine. Stirring is a great way to bring flavor into white wine. All of our Chardonnay is fermented in barrel, and so as that yeast died, they settled down to the bottom of the barrel. And by stirring the barrel, we’re mixing them back in with the wine where all of the contents of the yeast cells are being released. And those are the polysaccharides and nano proteins that make the wine really thick and delicious. Because it’s a small vessel every time you open that bun on the barrel, you’re getting a tiny bit of oxygen in.
So you get slightly more oxidative aging in a barrel than you would in a large tank. We call the evaporation from a barrel the angel’s share. So that’s a wine that is going out into the air, and the barrel is becoming lower and lower. So we have to top that up with fresh wine to prevent oxygen from getting into the barrel.
Racking is another important subphase in the process of making wine from grapes. Racking occurs several times during the life of a wine. Racking is where you take all of the wine from one lot or block of grapes, and you pump all the barrels out into a tank. You clean all your barrels, and then you pump the wine back into the same barrels or different barrels. Depending on the flavors you want.
Blending can be done at any time during elevation. I like to let the wines age for at least eight months before I start blending. I think that is a good point to really see the long term flavors and character of each wine. Winemakers blend wines from different grape varieties vineyard sights or styles to create a more complete wine.
Don’t forget on protection in the process of making wine from grapes. The biggest enemy of wine is access to oxygen while wine may benefit from a small amount of oxygen. For most wines protection from excessive oxidation is achieved with the addition of sulfur dioxide. Sulfur dioxide is a preservative that’s been used in wine for hundreds of years. They used to burn sulfur wicks in the barrels. Sulfur dioxide is, and it’s also somewhat antimicrobial. Sulfur dioxide can be added at various points throughout the winemaking process. Depending on the condition of the fruit and the style of the wine. As the sulfur stays in the wine, it reduces over time. Relatively very quickly. So each time we open the barrel will check the sulfur, and maybe we’ll make a small addition. If you’re in a rush to get into the market or it’s your preference there are stability things you can do to the wines. Chilling, fining, filtration. There are lots of tools to get the market ready.
In the process of making wine from grapes, we can use filtration. Filtration is removing sediment from the wine. The wine might be a little bit hazy and then it’s a winemakers opinion that that haze can be a little bit bitter. Sometimes filtration just comes down to a stability issue. If you bottle wine and it has enough malic acid or enough residual sugar or not enough so2. For something to go wrong in the bottle. Then you want to make sure that you’ve removed any yeast or bacteria that could become active.
The Seventh Step in Making Wine from Grapes – Bottling
Once the wine has been bottled finding agents such as egg whites or clay may be used to improve the tannin structure clarity or aroma of a wine. The bottle is the last opportunity a winemaker has to influence wine quality. I don’t want to bottle a wine until I feel that the wine has developed and reaches an appropriate level regarding balance and interest. And that can vary. It’s not on a calendar. Every wine will develop differently. Bottling lines are complex with many opportunities for error. It may not be the most romantic part of the process, but this overlooked aspect is essential to ensure quality. Some faults can affect wine quality and as a winemaker that’s the last thing that you want to have happened to your wine.
Clean Cellar Practices
I think the biggest problem with most wineries is microbiological spoilage which can occur from a variety of sources. And we try to be very careful. Make sure your all environment is clean and well maintained. And keep the wines without undesirable yeast or bacteria. Yeast or bacteria can impart flaws such as high levels of volatile acidity or barnyard aromas. Most microbial spoilage can be avoided through clean cellar practices.
At low levels or when done intentionally, some wine faults may add interest to a wine. Cork taint, however, is always seen as a flaw which has led to experimentation with cork alternatives. Beyond natural cork there rated corks. There are lots of plastic closures. There’s glass closures and then, of course, screw cap.
There are many options available to winemakers today. The same wine under different closures will vary regarding the consistency rate of oxidation and flavor. Cost consumer perception and convenience are also important factors. Patience is essential. You can’t be an impatient person when you’re making wine. Decisions are very long and slow. While the fundamental principles of winemaking are universal practices, vary by region grape variety and wine style allowing winemakers to craft unique expressions. Every wine is a new experience it’s got its journey. And if you listen carefully enough, they’ll tell you what it wants to be where it wants to go.