Everyone knows what wine is. Wine is an alcoholic drink made from grapes.  It comes in two varieties, red and white, and sometimes it bubbles. What more needs to be said. The average person doesn't think too much about wine, where it comes from, and how it is made.  And if the average person did stop to think about it, puzzlement would result.  An alcoholic drink made from grapes? Where does the alcohol come from? Our hypothetical puzzled person is left pondering the difference between grape juice and wine. Grape juice is obviously made from crushing grapes for their juice.  Wine, then, must be grape juice with some extra steps involved.

In fact, wine is a more natural drink than grape juice. You do get grape juice from crushing grapes.  But if you do nothing else and wait long enough, your grape juice will turn into wine.  Not very good wine, probably, but wine nonetheless. How does this happen? Well, left to itself, the juice from a crushed grape will naturally ferment and produce alcohol.  In very simple terms, the process looks like this

sugar + yeast  alcohol + CO₂ + heat

Obviously, sugar comes from the grape.  Anybody who had ever eaten a grape knows how sweet a grape can be. But where does the yeast come from? As a matter of fact, the yeast also comes from the grape, or more accurately off the skin of the grape. Natural yeast is attracted to sweet thin-skinned fruits such as grapes. If you plan to preserve your grape juice, it is important to pasteurize it to kill off most of the yeast and prevent fermentation.

It is no wonder that wine was once known as the nectar of the gods.  Every grape is a little wine making factory, with all the necessary ingredients coming naturally in tidy little packages.  Of course, although simply stomping on your grapes and letting the resulting mess sit for a while will produce an alcoholic beverage that could, loosely, be described as wine, if you want good wine the process is somewhat more complicated.  There are many many variables that must be juggled when progressing from grapes to wine.

The most significant variable is the grape itself. What variety of grape is it, and is the grape variety suitable for making good wine?  A bunch of Chardonnay grapes will produce a vastly different wine than a bunch of Cabernet Sauvignon grapes, and there is a reason why no one makes wine from Concord grapes anymore. Even once the variety of grape has been nailed down, there is the question of how ripe the grapes were at harvest. How much sugar is in the grapes? What is the level of acidity? In general, as grapes ripen the sugar goes up and the acidity goes down.  Depending on the grape variety and the desired style of wine, there is an optimum sugar/acidity balance. If the balance is out of whack, it must be compensated for before or during fermentation or the resulting wine will be out of whack as well.

Once the grapes are crushed, things get really interesting. First off, to produce white wine the grape juice is separated from the grape skins, pulp, and seeds.  To produce red wine, the juice, skin, pulp. and seeds are left together in a thoroughly unpleasant looking mixture known as the must. This allows the pigment from the skin of the grapes to seep into the juice, which is what makes red wine red. With the colour comes tannin and all sorts of interesting flavours, making red wine generally more complex in taste and structure than white wine.

At this point a decision must be made about chaptalization. That is, the adding of sugar to the unfermented must. Adding sugar during the wine making process sounds like heresy but it is actually widely practiced. The reason for chaptalization is not to make the wine sweeter but to make the wine more alcoholic. Remember that alcohol is produced by yeast acting upon sugar, and in cool climates the harvested grapes often do not contain enough sugar to obtain the desired level of alcohol. By adding sugar up front, the wine maker is raising the alcohol level of the final wine.

The next step is fermentation, and there are yet more choices to be made. Is fermentation is going to driven by the natural yeasts that come with the grapes, or will a yeast additive be used? In some people's opinion, using natural yeasts results in a more natural wine, and is the approach that best lets the environment of the vineyard, a.k.a the terroir, express itself.  However, using yeast additives provides much more control over the fermentation process and ultimately the final product.  However achieved, the fermentation process must be closely monitored.  For one, fermentation produces a lot of heat, which must be controlled since fermentation temperature has a big impact on the quality of the final wine.  Fermentation can also halt too soon, known as "stuck fermentation", leaving residual sugar in the wine.  Faults such as Hydrogen Sulphide (rotten egg odour) can creep in during fermentation. With all the things that can go wrong during fermentation process, it is no surprise the the wine makers of the world are very busy people immediately after harvest.

Fermentation can take from one to several weeks, depending on the temperature at which fermentation takes place (the lower, the longer). When fermentation is complete, there is still more to do. The wine must be siphoned off of the lees, which are the dead yeast cells left over after fermentation is complete.  Red wine must be pressed to separate the wine from the skins and the other remaining solids. If the wine is to be aged in barrels, it is transferred into barrels. At a $1000 a barrel, barrel aging is not a decision to be made lightly. In addition to the cost, the barrels must be stored somewhere cool and dry for months, even years, with the up-side being a really impressive photo-op on the winery tour.

Finally, and it's about time, the wine is ready for bottling. Most wines, once ready for bottling are also ready for drinking.  Some wines, especially highly tannic reds, will require even more aging in the bottle before being ready to drink. How much time elapses from the picking of the grapes to the drinking of the wine? It depends on the wine, of course. At one extreme is Beaujolais Nouveau, which ends up on your table a mere 6 weeks after being harvested. At the other extreme is vintage Madeira wine, which can be aged a century or more. However, the average wine will end up in the bottle after 3 to 6 months, or 1 to 3 years if oak aging is required.

If you have read this far, you now know how to make decent wine...NOT! Wine making is truly an art, and like anything worth doing it takes years of practice before you can do it well.  This article touched on the basics, but left out more than it included. In fact the topic of wine making is almost infinite in scope. Like a fractal art image, no matter how close you look at wine making, there are always more details to be found.

Does this mean you should give up your aspirations of becoming a premier wine maker? Hell no! If you really want to journey into the art of making fine wine, just be aware that with all journeys you must start at the beginning and wine making is no exception. Also be aware that you don't need to move to wine country either. There are wine makers out there who started at the local do-it-yourself wine shops and are now making fabulous wines in their laundry rooms and basements.

I myself don't do that.  I don't make wine at all. In my opinion, why bother making our own when there is so much wine from all over the world to be bought and drunk. I do, however, find the wine making process fascinating. An understanding of how wine is made increases your appreciation of wine, just like an understanding of the structure of a fugue increases your appreciation of Bach. For anybody who has wondered what is this thing called wine, a knowledge of the wine making process makes all the pieces of the puzzle in your glass fall into place. And few things are more satisfying than a completed puzzle.