As much pride as our world-famous wineries claim to have in their century-old establishments, the majority of the burden of wine making actually falls to a single-celled organism: yeast. In fact, much of the art of wine making is actually the art of feeding and nurturing the yeast. A famous quote from Dr. Roger Boulton from the University of California illustrates: “Ninety percent of wine making has nothing to do with the winemaker. All a winemaker is doing is preventing spoilage, introducing some unique style to the wine and bottling it.”

So what is yeast, and what is it doing? Yeast is a single-celled organism, a strain of fungus. It moves freely in the environment and when it finds nutrition it replicates quickly to form a colony. The earliest known usage of yeast was in ancient Egypt, where it was often used for bread making. In fact, anyone who has ever had to culture yeast for bread making will understand much of what it takes to be a winemaker.

There are many different kinds of yeast, and the ones generally helpful for wine making are of the genus Saccharomyces (Sakchar meaning sugar and Myces meaning fungus), of which there are over a dozen to pick from, each which adds different characteristics to wine. The yeasts of this genus consume the natural sugar found in fruit juice and transform it into almost equal parts of carbon dioxide and alcohol.And there’s the rub: without yeast, it’s just grape juice.

So then, if wine making is an art, then its primary tool is the ability to control yeast. Fresh pressed grape juice will typically already have dozens of different kinds of yeasts, as well as a number of other microbial invaders. If you left the juice as is, it would develop into wine on its own, though it would likely be over-alcoholic and undrinkable. To create a truly great wine, the winemaker must have a specific yeast in mind, introduce it at the right time, feed it and nurture it, and allowing it to die and be cleaned whilst preserving the fruits of its labor. This involves a rigorous control over temperature, humidity, and quality of fruit.

Over the many centuries since wine makers have bottled their products, they have been returning the old skins and seeds of crushed grapes (the pomace) to the vineyards to be used in fertilization. The grape skins are breeding grounds for yeast, and by returning yeast-rich pomace to the vines, vineyards have managed to subtly alter the natural yeasts that occur in their fields. Over time, the selected strain of yeast begins to dominate so rigidly that a winemaker can simply encourage spontaneous fermentation. Those making homemade wines don’t have this luxury, and even established vineyards may be centuries away from such a yeast domination.

So despite the vigilant claims of expert wine makers across the world, it’s obvious that the real master winemaker is yeast.

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Making home-made wine is a wonderful and easy way to profit from your home grown grapes and all the work you put into growing them. The basic steps for wine making are:

• Picking the grapes
• Crushing the grapes
• Fermenting the juices
• Clarifying and bottling the liquid
• Aging the wine

For white wine you use white grapes and for red wine you use red or black grapes. However, you can make white wine from red grapes if you first remove the skin. You might also need to remove the seeds and stems. Each component of the grape, including the stems and the skins, contribute to the aroma and flavor of the finished wine.

Materials:

To make one standard bottle of wine (75cl) you will want about two pounds of grapes. Ten pounds of grapes will yield a gallon of wine. In addition to the grapes you will need a few accessories for making your wine. Visit your local wine-making supply store to find the items or look on the Internet for suppliers. Here is a list of the essential items.

• Grapes
• Large vat for crushing grapes
• Hand masher (or use your hands)
• Bottles, corks
• Campden tablets
• Wine Yeast
• Barrel fitted with an airlock
• Syphon and carboy (clean and sterilized)
• Hydrometer (To measure the specific gravity)

A wine-making kit is the easiest way to get started, and as you progress you might enjoy upgrading your tools as you gain experience in using them. You don’t have to crush the grapes by treading on them. This is a good way to do large productions, but for small productions, mashing them by using a hand-masher (or your hands) will do just as well. Don’t fill the vat too full because the grapes will foam and froth as they ferment. When the grapes are mashed, leave them for a day or two before beginning the fermentation. Campden tablets are used to prevent wild yeast from growing during this stage.

Proper wine yeast should be used, not bread yeast, because the flavor is quite different. Stir in the yeast by hand, cover the vat and leave the wine to ferment for about a week. At the end of the week you can strain the wine. The bubbling and boiling effect should have subsided before you strain the wine and throw away the pulp. Pour the liquid into a barrel with an airlock so that carbon dioxide, which forms as the wine ferments, can escape. The wine should be protected from exposure to the air at this stage or it will oxidize and won’t be good for drinking.

Over the next two to three years, sediment will fall to the bottom of the barrel and the liquid will turn clear. After about three weeks the wine is ready to “rack” or siphon into the carboy to remove the clear wine from the sediment. The carboy should be sterilized to prohibit the growth of bacteria. Siphon the wine every couple of months as the wine ages. When you notice there is no fresh sediment, and the liquid is perfectly clear, the wine is ready for bottling. Another test is to check the specific gravity with a hydrometer. It should be below 1.000.

As you can see winemaking is quite easy. Making truly fine wine, however, is an art as well as a science. Aging your wine a few more months in the bottle will improve the flavor, but once it is bottled, you can basically begin drinking it.