Wine-making 101

The illustrious hobby of wine making:

This post covers the very basic principals of wine making.  It's a very in-depth topic and will be discussed in more detail later on. If you’ve never made your own wine before it may sound like an arduous process. Most think back to the Romans, stomping the grapes with their feet and pressing it into wine. Luckily, the wine industry has advanced signifigantly since those times and making wine is easier than ever.

First, a little background information:

“Alcohol is what results when yeasts metabolize with the natural sugar in grape pulp.” 

Using this principlemaking wine is almost as simple as adding some yeast to some grape juice. Granted, it’s slightly more complex than that. After all, there are different styles of wine and different types. Nonetheless that is how wine is made with a few extra steps in between.

Mechanical Harvester
Photo courtesy of AP Images

Usually, in order to get the grape juice/pulp in question there is a harvest that is done. Originally, all harvests were done by hand. However, in this technological day and age we now have mechanical harvesters which most farms use to obtain their grapes. From the harvester, the grapes are usually placed into the crusher/stemmer. This device squeezes the juice out of the grapes and removes the stems. Crushing is done in different ways. Many wineries will just use the “free-run juice” that comes off before the first crush. This is for higher quality wines and white wines usually. When making red wines, we will save the skins and ferment them with the juice. More crushing of the grapes is usually to get more color and/or flavor from the skins of the grape.   

If you're just starting out, you'll probably want to purchase a kit for your first time.  They come with step by step instructions to ensure that your first wine is a success.

Now that we have juice, we need to turn it into wine. It is important to note that most places have ambient yeast (meaning that the juice will in fact ferment on its own if we do nothing).

 “A winemaker, however, may choose to use cultured yeasts, thereby gaining control over the onset and rate of fermentation. Something as simple as the speed at which fermentation proceeds can profoundly affect the flavor of the wine, with slower fermentations often producing more complex wines.” 

Many home wine makers will also want to select a cultured yeast from a lab such as Lalvin. This allows you to select a yeast that is going to impart the specific flavor profile you are looking for in your wine.  The selection process can be intensive and it is best to use a manual such as Scott Laboratories Fermentation Handbook.

Once the juice is fermented successfully it is officially wine. However, it is still not ready to drink. The next step is to stop the fermentation process to make sure that a secondary fermentation does not happen in the bottle (this can lead to messy explosions if not done properly). Many modern wineries use pasteurization to kill off the remaining yeast while others rely on additives or micro-filtering. For home wine makers, a campden tablet per gallon and a potassium sorbate or sulfite additive will do just fine. Some wine makers would not consider the wine nearly complete at this stage.  Many wines are aged for years in oak and home wine makers might use oak barrels or additives to simulate the ask flavoring which would be acquired by barrel aging.

Corker
Photo by Melody Flammger

Now that we have wine that won’t explode when we bottle it, we must now clarify the wine. Who would want to drink wine with floating masses in it? In order to do this, many rely on clarification agents, however this can also be done through filtration. Different filters can be used for different effects. For instance, if you are trying to filter out leftover yeast, you may want a micro-filter which filters to 1 micron thick. That way, none of the yeast can pass through the filter. If you are just filtering for aesthetics, you can use a coffee filter or a wine filter you can find in any supply store where you go for your wine making needs. For clarification, I like the use of sparkoloid powder. After adding this clarifiying agent you would want to let the wine sit for an additional week or so to give the agent time to pull the sediment to the bottom of your fermenter. I do recommend use of a filtration method along with the clarifying agent to ensure better looking wine once it is bottled.

Source: MacNeil, Karen. "Where It All Begins, How Wine Is Made." The Wine Bible. New York: Workman Publishing, 2001. 7,32. Print.