How Wine Is Made

What Is Wine?

What have you, been living under a rock?! Maybe you’ve just turned 18? I’m not even going to be naïve and say 21. I tease, I tease. All right, I get it…sometimes we need a little high-level refresher course on the things we love the most, so join us as we take a look at how wine is made!

Wine is an ancient beverage that has become one of the most popular adult beverages to drink in modern times. By official Oxford Dictionary definition, wine is an alcoholic drink made from fermented grape juice. While each country has their own standards, here in the US it is legally defined by the Alcohol and Tobacco Tax and Trade Bureau as having a minimum of 7% alcohol by volume (ABV) and a maximum of 24% ABV.

You can, of course, make wine from fruit other than grapes…but legally there must be a qualifier so you know what the base is if it’s anything other than grapes. So it would say “apple wine” if it’s wine made from apples, for example, but we’re going to stick to the classic today and just focus on good ‘ole wine made from grapes.

The United States leads the world in wine consumption and is fourth in wine production behind Italy, France and Spain. Everywhere you go these days, someone is shouting Rosé All Day or bringing you a big, bold red (anyone, anyone? C’mon…where’s my glass of red?! Hold on a minute). So we figured since we're all enjoying it so much, let’s make sure we understand how wine is made so we can appreciate it even more and ask the right questions to find new favorites as we’re exploring with craft producers…

How Wine Is Made

Ok, let's get into it and talk a bit more about how wine is made. We'll break down the process and go into each key step at a high level for our quick “crush course” on wine (sorry, I couldn’t help myself. Teaching others how wine is made always gets us excited!):

Wine Grapes

Harvest

While picking grapes may seem pretty straightforward this is honestly one of the most important phases in the winemaking process…when exactly to pick the grapes! Of course, before the grapes are picked they must be planted and grown. Interested in that process? Make sure to join Tippler Nation so you don't miss our upcoming article on the importance of soil, climate and the five phases of grape growth. Or rather, the "growing of the wine." But for now we're focused on making the wines once the grapes are ready so back to Harvest!

Typically all grapes are harvested around the same time of year in each region (late summer/early fall in the CA wine regions in the United States, for example), but the exact date can have a pretty major impact on your final wine. The timing of the pick depends on the grape variety, the weather that year, and the constant evaluation of the grapes in the vineyard in the weeks and days leading up to harvest. Ideal ripeness in grapes is a combination alcoholic ripeness (ie sugar level) and physiological ripeness (which includes phenolic and aromatic maturity).

The Importance of Brix

Brix is a term for the measurement of sugar in grapes, which also relates to how high in alcohol the resulting wine may be (more sugar = more alcohol potential!). If you pick grapes earlier, the brix and resulting alcohol will be lower, the acid will be higher and you may have more “green” flavors and more bitter, astringent tannins. If those same grapes are picked later they will have a higher brix/alcohol potential, lower acid and more ripe fruit flavors with softer tannins.

How wine is made - grapes being harvested by hand

As I said…this is pretty critical stuff to get right! So come harvest season you’ll see the vineyard workers testing brix, pH, and other variables often to make sure they don’t miss the perfect window for exactly what they’re hoping to create.

For fine wine production, the grapes are often harvested by hand in the wee hours of the morning. Crews of skilled workers move through the vineyards selecting the optimal bunches and removing them from the plant as whole clusters, moving with precision and experience in the pre-dawn light. Picking is done early so the grapes can be fully processed before the heat of the afternoon. Think about it, if you're running errands, you visit the grocery store last so your produce doesn't bake in the car while you're getting your haircut or getting a cavity filled. Mechanized harvesting alternatives exist and have become more popular as labor shortages become more common. While efficient, this technique can be problematic as the machines can damage the vines and also harvest indiscriminately, collecting all the runts and raisins along with the ideal grapes. And when it comes to how wine is made, that is no bueno.

Crush

How Wine Is Made

Grapes are delivered to the winery from vineyards near and far to be processed on what is often referred to as "the crush pad." The clusters are unloaded on to a conveyor belt where MOG or Matter Other than Grapes can be more easily be plucked out (leaves, sticks, rocks, etc). At this point, what happens next depends on what type of wine is being made. For red wine, the grape clusters are often put through a crusher/destemmer to remove the grapes from the stem and break them open or crush them. The juice, mixed with the skins and seeds (this mixture is known as the must), is then pumped into a fermentation tank to await the fun part. Occasionally, whole clusters are put directly in the fermentation tank, as the stems actually can provide some texture and flavor to the resulting wine. In the production of white wine, the juice is separated from the skins and seeds before being fermented. White wine grape bunches are either crushed/destemmed and pumped into a press or sometimes whole cluster pressing is done depending on the intended style of white wine being made.

Fermentation

This is where the magic begins! Fermentation is simply the transformation of sugars into alcohol caused by the presence of yeast. But where does the yeast come from? Well, many minimalist winemakers prefer to rely on native or ambient yeast…or yeast that is naturally present on the grapes themselves, in the wine cellars, and in the fermentation rooms. Winemakers more focused on terroir and natural winemaking often prefer using these yeasts, but the downside to letting ambient yeast run the show is that it’s quite a bit more unpredictable. While that can often lead to highly unique and amazing wines, it can also lead to some less desirable characteristics or in the worst case scenario, bad wine. The other, more predictable approach is to use cultured yeasts that are specifically created for winemaking. Yeast is added to the must waiting in the fermentation vessel and as the yeast comes in contact with the sugars in the must, fermentation begins!

During fermentation, the winemaker has to decide on how much they want to control the temperature, how long to let the must ferment and how long to leave the skin in contact with the juice (or how long to allow maceration). While all three of these variables are hugely important, the last one is the one you’ll notice the most in the glass you’re sipping.

The skins are where the tannins are found. And tannins are what cause that tart, somewhat bitter, dry-out-your-mouth sensation that you find in red wine. Tannins are also found in tea…so when you let your tea bag steep too long and your tea gets bitter? Tannins! While many people think that all reds are tannic it really has to do with the grape variety and the maceration time…so if you’re someone who has been sticking to whites and rosés for fear of tannins it’s time to start experimenting with reds specifically made to be less tannic! Don’t worry…we’ll help you out on your journey here in future articles. The Crafty Cask has your back.

Fermentation takes about two weeks to complete if you're using a cultivated strain of commercial winemaker's yeast. At this point, you've technically got wine! CONGRATS! But for most wine, the journey is not even halfway done.

Aging

how wine is made - barrel aging

From the fermentation tank, the fermented grape juice (or shall we say wine!) is transferred into an aging vessel. For most red wine, this is some type of oak barrel. White wine is aged in barrels as well, but often aged in stainless steel and even concrete too. Aging is a very important step in how to make wine. The time the wine spends resting allows for the introducing of flavors from the various vessels, a softening of the acidity and tannins found in young wines, and an integration of the flavors and aromas developed during fermentation.

The decisions made by the winemaker with regard to the aging process are often compared to a chef seasoning a dish, with the grapes as the ingredients in a meal and the barrels as the spice rack. Imagine making a fillet of whitefish. A little squeeze of lemon and little dusting of salt might be all the more seasoning you need, lest you overpower the mild flavors of the whitefish. Now imagine how you might season a well-marbled cut of ribeye. Some heavy paprika-coffee rub with lots of salt and pepper? At minimum, PLENTY of salt, because you NEED it to cut through the fat.

So for this analogy, the whitefish is a light, bright, white wine like Sauvignon Blanc and the ribeye is a big, bold, red wine like Cabernet Sauvignon. Light, white wines rarely spend time aging in oak – and if they do, it's usually only a small percentage of the total production, the barrels used tends to be neutral oak that has been used a few times previously, and it only sits in these barrels for a short time. Just a sprinkle of seasoning!

Conversely, big, bold red wines are often aged entirely in 100% new, unused oak barrels for many months or years. This allows time for much more of the flavors found in the wood to leech out and complement the bold character of the wine. Rub that flavor in!

Blending

After the wine has completed the aging process it's time for the winemaker's prowess to shine. Samples of different wines are drawn from the various aging vessels used. Graduated cylinders and pipettes are retrieved and set up so the mad scientist process can commence. We often think of wines labeled as a blend in a rather narrow sense, as in a blend of different types of grapes, like Cabernet Sauvignon blended with Merlot as is the case in Bordeaux. But in the production of fine wine, basically every wine is a blend.

For example, even if a wine is made from 100% Cabernet Sauvignon grapes, those grapes are often coming from different vineyard sites which produce different characteristics in the grapes. And in the instance of a 100% Cabernet Sauvignon coming from a single vineyard, the wine is being aged in different barrels. And even if all the wine is going into 100% new oak, the barrels used are coming from oak grown in different forests, made by different cooperages (barrel makers), with varying techniques to their craft. In the end, all these variations need to be reassembled to make the final product.

How wine is made - evaluating red wine blends

This process can be time-consuming and tedious as potential compositions are created and evaluated subjectively by the winemaker and their team, sniffing and sipping for hours on end. But this step is truly vital to the eventual enjoyment of the wine, creating a blend that has balance, polish, and integration. When asked what the single most important device was for making fine wine, acclaimed Ridge Vineyards winemaker Paul Draper responded, "The wine glass."

Once the final percentages have been determined, the appropriate amounts of the appropriate wines are pumped from their respective aging vessels into a holding tank for the different flavors to marry together before being bottled. Often wines go through a phase after being bottled when their flavors, aromas, and character are somewhat muted so it is common for wineries to hold on to wine after it is bottled for a few months before releasing it to the public to enjoy. This is commonly referred to as bottle shock and, no, it doesn't involve the wine changing color, despite what Hollywood may have suggested in the movie of the same name.

Conclusion

It's remarkable how many steps are involved in modern winemaking, honestly many more than are included in this brief overview. Funny to remember that at the same time this product is basically spoiled grape juice that we as humans have been making and enjoying prior to recorded history. But to that we say, raise a glass. Enjoy this spoiled grape juice and give a minute of thanks to the many hands that have touched it along the way to bring it from grapes hanging on a vine to that beautiful sip you're about to enjoy in your mouth.