Jim Bruce's Article On
Making Red Wine
These massive fermentation tanks are part of a large industrial wine-making complex. Don't
jump to conclusions. Don't assume that the ensuing wine will taste "industrial." Skilled winemakers
can produce fine wine in huge quantities.
Our Introduction To Making Red Wine
Bruce offers a detailed but highly readable explanation of the steps in making red wine.
Among the technical terms that he demystifies are primary fermentation,
secondary fermentation, malo-lactic fermentation,racking,
cold stabilization, fining, and filtering.
Title: Making Red WineHarvesting Your Red Wine Grapes - The first step in making red wine is to have the grapes perfectly ready to be picked. They need to be harvested not only at the proper time in their life cycle, but also at the right time of day to ensure the acids and sugars are all at the right balance for the wine.
Author: Jim Bruce
Red wine grapes should contain enough sugar to be considered ripe and be able to attain the alcohol content you are aiming for. They must also have the right balance of acids. This means "hang-time" on the vine until the grapes have met the proper quality factors. A sugar content of 24 Brix at harvest will give you about 12% alcohol.
De-stemming and Crushing - This step in making red wine removes the stems from the grape bunches, and crushes the grapes (but does not press them) so that the juices are exposed to the yeast for fermenting. This will also expose the skins so they can impart color to the wine while in the primary fermentation.
This step in making red wine can be done manually by squeezing the grape bunches over a grate with holes to allow the grapes and juice to go through while leaving the stems behind. I've used old Coke crates, perforated plates, and other means to accomplish this. (Depending on the type of wine, the stems could be left in for a more tannic flavor or removed). This mix of wine is called must and is put into a fermentation vat.
You can always "stomp" the grapes and remove the stems afterwards - the old fashioned way. There are
crusher/destemmer machines that can be purchased if you have a lot of grapes to crush. If you are going to adjust the acidity, this is the time to do this.
Primary Fermentation - The must is held in a vat that can be made of food grade plastic, glass, or stainless steel for fermentation. In whichever container, the sugars inside the grapes are turned into alcohol by yeasts. The yeast used should be specific for red wine. This fermentation process typically takes from 3-4 weeks.
How long the must (juice and grape solids) is allowed to sit, picking up flavor, color and tannin is up to the wine maker. Too long and the wine is bitter, too short and it is thin. Temperature is very important during this stage - it also affects flavour and color.
Punching Down the Skins - Skin and other solids float to the top as fermentation proceeds. The carbon dioxide gas given off by the fermentation process pushes them to the surface of the developing wine. The rising skins are called the "cap" and need to be pushed back down to stay in contact with the must. This should be done a couple of times a day. As you punch down the cap, you will notice that the wine is taking on more color from the contact with the skins.
End of Primary Fermentation(?) - The winemaker must decide if the must has fermented long enough. This will take a few days to a week. Much of this decision depends on how much color you want in your red wine. Generally, the wine has not completely fermented at this time. There still should be some residual sugar that will need to go through further fermentation.
Remove Free Run and Press - At the end of the primary fermentation, the must is put into the wine press. The best quality wine is made just from the juice portion of the must. Many wine makers allow this to run off and save it for the best red wines. The rest of the drier must (now called
pomace) is pressed.
Pressing squeezes the remaining juice out of the
pomace. If you do it too hard, or too many times, you get low quality wine. You can save the pressings separately from the free-run or it can be combined. This pressed wine will take longer to become clear and ready for bottling.
Secondary Fermentation - The juice, now wine, needs to settle after this ordeal and continue to ferment out all the residual sugars. During this time, the wine should be stored in glass carboys fitted with fermentation locks.
Fermentation locks keep oxygen out of the wine while allowing the carbon dioxide from fermentation to escape. Without them, oxidation will occur and the wine will spoil into vinegar or something worse. In the lack of oxygen, the wine undergoes subtle changes that affect the flavors of the resulting wine.
Malo-Lactic Fermentation - Many red wines need a non-alcoholic fermentation to remove excess acidity. This secondary fermentation will turn the tart malic acid (of green apples) into the softer lactic acid (of milk). A special
malo-lactic bacteria is added which allows malolactic fermentation to occur. This is done during the secondary fermentation. Wines are held at about 72F during, or at least at the end, of the secondary fermentation to favor this activity. The yeast that has settled to the bottom during the secondary fermentation also favors this process.
Racking and Clarification - Moving the wine from one container to a new container by siphoning allows you to leave solids and anything that might cloud the wine, behind. This clears the wine and prepares it for bottling. Fermentation locks must be employed with each racking to keep the wine from spoiling. Wine is racked at least once but more may be needed to assist clarification.
Cold Stabilization - During one of the aging stages between rackings and bottling, the wine can be placed in the cold of refrigeration to be stabilized. This cold period will make the cream of tartar settle out of the wine and reduce the acidity further. The wine is then racked off the cream of tartar during the next racking. I suggest you do this early in the racking and aging process of making red wine.
Aging - The wine is stored for anywhere from 9 months to 2 1/2 years to give it the correct amount of flavor. Oak barrels can be used for aging but they are very expensive.
Nowadays, when making red wine at home, oak chips are used. The amount of time you age your wine with oak depends on the flavors that you wish. At the end of the aging period, you will be ready to bottle.
Fining or filtering - At the end of the aging period it helps to remove anything that may be making the wine cloudy. This can be accomplished with various fining agents (like
sparkalloid), with filtering, or both. This makes the wine crystal clear for bottling and will prevent any sediments from forming during bottle aging.
Bottling - This is done carefully so that the wine does not come in contact with air. Finer wines may be stored for several years in bottles before they are drunk. But I suggest that a minimum of 6 months to a year lapse before drinking.
So there are the steps in making red wine. Properly done, you will have a wine that will not only give you drinking pleasure, but will make you the envy of your family and friends.
About the author:
Jim Bruce has been making growing grapes and making wine since 1974. You too can grow your own wine grapes. Interested in growing your own grapes for making wine? You can buy his Tips for Growing Grapes eBook at http://www.grapegrowingbook.com