Credit to photo: Shutterstock/Rumka vodki; Alefat
Text by: Gleb King
How wine is made: white dry wine
According to Einstein's theory of relativity, time is relative. So is the wine. It depends on time heavily. First it needs old enough vines to bring worthy fruit, then it asks for a full season of ripening, then it has to spend weeks in a winery and after it comes to the most time-worthy process – the aging. Hours, weeks, years or even decades – time is one of the wine’s ingredients. There are so many variables in wine’s life that It’s hard to form a universal algorithm of winemaking. Whether you crush grapes or ferment them intact, do you leave the juice on sediment or filter it out, do you let it contact with oxygen or not – it all depends on climate, grape varieties, winemaker’s choices, marketing guidelines and so on. It’s not easy to make a clear step-by-step guide to winemaking, but we’ll try.
«If you dig further, you may find some white Cabernet Sauvignons from South Africa and white Mourvedres from Washington»
White wine is mostly made of white grape varieties, but, as we have already metioned, in wine there are always options. You can make white wine also of red grape varieties if you separate the juice from skins – the color is there. There are some beautiful white wines made of black skin grapes – Blanc de Noirs Champagne made of red grape Pinot Noir is a perfect example. If you dig further, you may find some white Cabernet Sauvignons from South Africa and white Mourvedres from Washington. But all these are more like a deviation than a rule, so let’s stick to white wine of white varieties. The basic pattern of white winemaking is: pick the grapes – move them to the winery – press the juice out – ferment it – give it some time – filter – bottle. But let’s be more inquiring and see the whole process with all probable sideways.
1. Harvesting
The fundamental quality of most white wines is acidity. Whether wine is meant to be consumed fast or to be aged for decades, acidity is the boss. So, it’s crucial to pick the grapes on the edge of ripeness and freshness at the same time. Another important thing in white winemaking is full control. Oxygen and high temperatures are not welcome guests here – they may lead to premature fermentation and loss of acidity, so grape picking is mostly performed in early mornings or even at nights. Winemakers do their best to stay cool and bring the grapes to the winery as fast as they can to prevent oxidation.
2. Sorting
In French this process is called triage. In order to use only the healthiest and the cleanest grape clusters, a winery’s staff (or machines with highly expensive laser sensors) sort the grapes on the table. On most modern wineries the triage table is an assembly line with people working on both sides.
3. De-stemming / сrushing
At this stage the winemaker decides if he or she wants to add some «spice» from grape stems to the future wine. If properly used, the stems may add some green, vegetal or herbal notes to wine. In most cases the grapes are separated from stems, but it may happen that up to 50% of clusters proceed to the stage of pressing intact. If grapes are destemmed, they are crushed to let the juice out and go forward as juice and skins. This liquid is called the must. Crusher and destemmer is usually a big rotary machine.
4. Cold maceration
Some grape varieties need to spend some extra time in a cold and deoxygenated environment, to improve the aromatic qualities. For instance, cold maceration is frequently used with aromatic grape varieties such as Sauvignon Blanc or Riesling. Most of their aromas are hidden in skins and the winemakers pull it out by soaking the skins in juice.
5. Pressing
This stage defines red wines from whites. The reds go to the fermenter tank straight after crushing – with skins and (if needed) the stems. In case of regular whites, the winemaker needs only juice. So, it’s pressed out. On most of the modern wineries, this stage is performed by a huge horizontal vacuum press. Inside, the big rubber or plastic bags gently push the grape must to its walls. However, in some cases they still use a vertical basket presses or even (mostly in home winemaking) stomp grapes with feet.
6. Clarification
Freshly pressed grape juice is far from crystal clear. There are a lot of suspended grape particles in it, making it cloudy and uneven. The most popular way to clean the juice is to settle it in low temperatures for one or two days. In some cases the juice goes through a centrifugal machine to separate from heavier parts.
7. Fermentation
This is what makes wine the wine. Wine fermentation is a process of transitioning the sugars into ethanol by yeasts. There are two side-effects of fermentation – the rising temperatures and release of carbon dioxide or CO2. The first one is strictly controlled by winemakers because high temperatures lead to fast fermentation with undesired effects to the future wine’s aromas and tastes. This is why most fermenters are forcibly cooled or located in cooler environments such as wineries basements. By lowering the temperature, winemakers can slow down fermentation up to one or two weeks.
«Depending on wine region and winemaking traditions, fermentation vessels may be very different – from stainless steel tanks to concrete eggs or cubes, or wooden barrels»
CO2 or carbon dioxide, produced by yeasts – is actually useful. During fermentation it naturally prevents juice from oxidation, not letting the oxygen in. If wine is made to be still, CO2 is just let out from the tank. If not, the tank is airtight. When yeasts «eat» all the sugars, they fall to the bottom of the fermenter. The yeast sediment is called the lees – and yes, it’s useful too. Depending on wine region and winemaking traditions, fermentation vessels may be very different – from stainless steel tanks to concrete eggs or cubes, or wooden barrels.
8. Sulfitation
SO2 or sulfur dioxide is added on many steps of winemaking to stop the undesirable bacterial effects. SO2 is an antiseptic, antioxidant, and enzymatic inhibition additive. On this stage adding a strictly controlled amount of SO2 is essential – it preserves wine from second fermentation if it’s not desirable. But if it’s going to happen, the sulfitation is postponed.
9. Malolactic Fermentation (if needed)
Or the second fermentation. In fact, it’s not a fermentation because the yeasts now are already dead. Instead of them, the lactic bacteria called Oenococcus oeni turns the malic acid into lactic one. The result is a different type of acidity – it feels softer, more creamy and buttery instead of being crispy, zesty and fresh. Second fermentation is frequently used with chardonnay and viognier grape varieties to make wine softer and more full-bodied. Also, it’s a regular option for some Champagne wines to create buttery style.
10. Sur lie aging (if needed)
One more option to make white wine creamier and more full-bodied is aging on yeast sediment or the lees. In French it’s called «sur lie». Some days after fermentation, the yeast leftovers begin the process of autolysis or self-destruction. During this, some sugars and amino acids are released, making the wine rounder and more weightful. Sur lie lasts from some months to years, making wine huge, almost oily on the palate.
11. Barrel aging
Once more, the wine needs some time. And once again, a lot depends on time. Oak aging messages to the future wine the nutty, vanilla, woody and honey-like tones. This stage may take place together with the previous one – the wine with lees is held in a barrel. Though, in some wine regions and styles there may be no wood aging and the wine is reserved in steel tanks – with sediment or not – this is like cooking – each process is a spice. Which one is right – is the decision of the head winemaker.
12. Blending
Once again, winemaking depends on many variables – weather, grape healthiness, time of harvesting and so on. The winemaker’s mission is to conduct this orchestra. Actually, sometimes the winemaker’s job is improvisation like in jazz. You may make several tanks of wine with different parameters (sur lie or not, fast or slow fermenting, with or without stems, and so on) and mix them like perfume – to make the right balance. In the wine world the blending is called assemblage.
13. Filtering / Bottling
To clean the wine from any weighted particles, yeast leftovers, tartaric acid crystals and so on – it must be filtered. In most cases wine goes through a cascade of membrane filters. However, in some cases filtering is not needed. The bottling must be performed carefully – to prevent wine from extra oxidation. The small portion of oxygen captured under cork will influence the wine’s further bottle aging.
14. Bottle aging
Some producers decide to release wine after some time of aging in their own cellars. It may take from one year to decades in strictly controlled temperature and humidity, prevented from direct sunlight. After the wine is released – it may be aged further by the consumer or the wine trading company.
