If you were to look at the free-run juice from red and white grapes you wouldn’t see much difference. In both cases the free-run juice would be similar in color and consistency. Red wine is produced when the skins are allowed to macerate in the must for a specific period of time. However that’s not the only thing that separates red wine production from white wine production.
The steps for making red and white wine involve similar steps but at different times in the wine making process. Below we’ve listed all of the steps for making red and white wine together to help demonstrate the difference in the processes. Remember, before you start making wine clean and sanitize your equipment; barrels, carboys, bottles, EVERYTHING!
Harvesting
When to harvest your grapes will vary depending upon your type of grape, terroir and the style of the wine you hope to produce. Some grapes produce sugars slowly which delays harvesting, while other grapes have thin skins that mandate earlier harvesting. So, while many variables are involved, the key is to find the right kind of balance for your wine.
De-stemming & Crushing Red and White Grapes
When de-stemming and crushing grapes of any color it is very important that as many stems are removed as possible. Stems are abrasive and leave behind unpleasant tannins. In red wine production crushing grapes produces a liquid that is called must which contains skins, seeds and juice.
In white wine production this step is usually skipped in favor of immediate pressing. However, some wine makers will crush, then macerate the skins for approximately 2 days to help add body to their wines, before pressing.
Adding to Fermentation Containers, Pressing
The must from red grapes is placed in fermentation containers; stainless steel tanks, oak barrels, and plastic tubs. There it rests for a few days.
Pressing white grapes must be done gently. Pressing the grapes with gentle pressure helps to completely separate the juice from the skins and minimizes the acid levels and tannins. The grape bunches can be left intact for what is known as “whole-cluster” pressing.
Adding Sulfur Dioxide and Yeast, Adding to Fermentation Containers
While natural yeast is present on the skin of the red grapes, cultured yeast is added to provide more predictable results. Sulfur Dioxide is used to help prevent the discoloration and oxidation of the must.
Depending upon the style of white wine to be made, the juice from the pressed grapes are stored in different types of containers. Wine makers choose barrels to impart tannins and other flavors like vanilla. Stainless steel tanks allow for more control over the entire process. Wooden vats, concrete tanks and plastic tubs are inexpensive and neutral on their impact to the juice.
Alcoholic Fermentation, Sulfur Dioxide Addition
While red wine must, rests for a couple of days, the addition of cultured yeast helps see the primary fermentation process through to completion. This stage usually lasts for about two weeks and occurs slightly above and below room temperature; depending on the varietal.
Along with preventing oxidization, sulfur dioxide is added in this stage of white wine making to also prevent spoilage.
Maceration, Clarification
After fermenting your wine must, you will still want to draw more colors and tannins into your juice. Leaving the skins of red grapes in your juice will allow this to happen. This stage typically lasts longer than the fermentation stage. During this stage a cap will form at the top of the fermentation vessel. This cap consists of the solids present after crushing the grapes. In order to extract more color and tannins many winemakers will punch down the cap allowing the juice and solids to mix more. Some winemakers utilize a rotofermenter that turns on its side to prevent the cap from forming. Note: This should be done until the cap stops rising back to the top of your primary fermentation vessel.
Clarifying white wine involves filtration, fining, cold stabilization, electrodialysis and racking. Filtration is reserved for high production wines as it has a tendency to remove tannins and other important characteristics. Fining occurs when a substance is added to the wine that bonds with particles and helps them to fall out of the wine as sediment. Cold stabilization crystallizes tartaric acid so that they can be removed through racking. Electrodialysis is a more efficient way of removing tartaric acid by passing the wine through two different membranes placed in electrically charged water. Racking helps separate the wine from the sediment.
Pressing, Selecting Yeast Type
Once enough color and tannins have been imparted on the red wine, pressing occurs. If winemakers hope to impart oak flavors on the wine, it is stored in oak barrels after passing through a vertical basket press.
In order to begin the the fermentation process for white wine, wine makers select their yeast. The addition of yeast allows for more control over the rest of the wine making process.
Malolactic Fermentation, White Wine Alcoholic Fermentation
Malolactic fermentation helps to lower the acidity in red wines. Leuconostoc bacteria, vitamins, nutrients and amino acids are added to the wine and the fermentation begins. The bacteria naturally triggers the fermentation and is aided by warmer temperatures. Grapes grown in warmer climates generally have lowered acidity and thus need less softening. Cooler climate grapes usually undergo more malolactic fermentation.
White wines are fermented between 50 and 68 degrees Fahrenheit. This stage lasts longer and is less intense than the same stage for red wines. Wine makers will allow the white wine to continue to ferment with dead yeast cells in order to further develop the body of the wine.
Racking, Barrel Aging
Racking separates red wine from sediments that develop during the previous stage of wine production. Leftover sediment is used as fertilizer in order to decrease the amount of waste produced from wine production.
Barrel aging white wines is reserved for certain grape types. Most white wine makers skip this step and rely on the fresh and fruity characteristics to carry the wine.
Clarification, White Wine Malolactic Fermentation
Clarifying red wine involves filtration, fining, cold stabilization, electrodialysis and racking. Filtration is reserved for high production wines as it has a tendency to remove tannins, color and other important characteristics. Fining occurs when a substance is added to the wine that bonds with particles and helps them to fall out of the wine as sediment. Cold stabilization crystallizes tartaric acid so that they can be removed through racking. Electrodialysis is a more efficient way of removing tartaric acid by passing the wine through two different membranes placed in electrically charged water. Racking helps separate the wine from the sediment.
Malolactic Fermentation is an important decision for white wine makers. Because this process lowers acidity in the wine, most wine makers skip this process. This way the tart acidity that white wines are known and valued for remains. Typically, barrel aging and this step go hand in hand.
Bottling and Labeling, Racking
After the clarification stage, red wine is ready to be bottled and corked. After aging in the bottle for some time based on the varietal, a label is affixed and the cases are shipped.
White wines that do not undergo barrel aging and malolactic fermentation are immediately racked following alcoholic fermentation. Leftover sediment is used as fertilizer in order to decrease the amount of waste produced from wine production.
Clarification & Bottling (White only)
After racking, white wines are clarified once more. Once clarification is complete the wine is bottled, corked and labels are affixed. White wine is not typically aged in the bottle. Sulfur is added as a preservative and to prevent any unwanted fermentation from occurring.
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