The Process of Making Red Wine

Producing wine requires turning grapes into an enjoyable beverage, and this article will outline all of the key steps involved with red wines production:

Crushing and destemming (the process of extracting stems from berries) are done to obtain must for fermentation purposes.

Fermentation – during fermentation, yeast feeds on sugar in wine to produce alcohol, heat and carbon dioxide; winemakers can control the temperature to extract fruity aromas during this process.


Step one of producing red wine involves fermenting grape juice – or must – using yeast. This fermentation process converts sugars to alcohol and carbon dioxide, creating red wine. Fermentation may occur naturally using native bacteria present on grapes or artificially controlled by using cultured yeasts.

At this stage, solids such as grape skins, seeds and stems will often float to the surface of the must, preventing proper extraction of color and flavor from the liquid. To maintain maximum color extraction and flavor extraction, these solids must be submerged back into it through punching down; regular punching down prevents these solids from drying out and turning brown, which could produce unpleasant flavors such as acetic acid.

Stirring must several times daily during this stage is also vital, as this ensures yeast contact with all parts of the must. Furthermore, regular stirring will keep oxidization to a minimum and maintain quality in your final product.

Fermentation will continue until all sugars have been consumed and it reaches either its natural or controlled endpoint. At this point, winemakers may opt to either stop fermentation by lowering temperature, or continue it for shorter periods to achieve more concentrated fruit notes. It is imperative that regular laboratory tests on wine be conducted, including Brix, pH, titratable acidity residual sugar and volatile acidity (V.A) measurements to monitor progress of fermentation.


Maceration involves extracting phenolic compounds from grape skins and seeds into wine (or must). The amount of tannins extracted depends upon how long pomace remains in contact with must, as well as the winemaker’s desired outcome.

Pulp of most wine grapes is typically colorless, while their skins contain an array of pigments and flavor compounds which contribute to wine structure and mouthfeel. During maceration, pomace is regularly pressed or pumped over to promote good juice-to-skin contact and increase extraction of tannins, color, aroma compounds. Pumping over also helps control temperature by adding oxygen into the tank which reduces premature oxidation risk as well as spoilage microorganisms like Acetobacter growth.

Cold soak, extended maceration and carbonic maceration are three primary forms of maceration. Cold soak involves chilling crushed and destemmed whole berries prior to fermentation for quick extraction of color and aroma compounds while simultaneously decreasing bitter tannins. The other methods involve slow maceration such as prolonged maceration or carbonic maceration which requires longer processing times for maximum extraction potential.

Extended maceration occurs both before and after fermentation and can last up to 100 days, producing wines with softer, suppler tannins as well as increasing their aging potential. However, extended maceration may also lead to polymerization which produces higher concentrations of small tannin molecules that may cause discomfort due to being perceived as bitterness.


Once fermentation has completed or near enough, winemakers use a press to press out additional juice from grape skins; about 15%-30% more juice comes out; this press wine boasts much higher tannin levels (which give its mouthfeel and herbiness) than free run juice; choosing how hard to press is an art in itself: too little pressure may produce light-colored or flavorless juice while too much could create harsh, pungent, less fruity results.

Red wine differs from white in its production by having grape skins exposed throughout its primary fermentation process; they give red wines their characteristic color and must remain present to produce high-quality wines.

Winemakers use maceration (soaking berries in juice for an extended period), commonly called maceration, to extract maximum color, flavor, and tannin from grape skins. Maceration usually takes place during fermentation but it can also occur prior by leaving crushed grapes sit in a tank at cool temperature for several hours to several days before fermentation begins.

Extended maceration for full-bodied reds can last as long as a week, helping the wine soften by turning tart malic acid into smooth lactic acid. This step mellows out any tart or acidic notes present and makes the finished product smoother overall.


Traditional red wines were too harsh and harsh for young drinkers to appreciate when first released, necessitating several years of bottle aging before enjoying. With modern winemaking techniques however, this step may no longer be required and some wineries opt out altogether.

Ageing wine brings great complexity in terms of aromas and flavors while maintaining its balance in its structure. Wood type and toast level play an important role, creating unique aromatic profiles depending on which oak variety and toast level was used during aging. Phenolic compounds from wood also play a part in imparting to wine such as ellagitannins (subset of flavonoids), hydroxycinnamic acids, aromatic polyphenols such as guaiacol or syringol.

Additionally, as wine ages and its tannins precipitate at the bottom of its bottle, leaving solid deposits known as sediment. This occurs because they lose their ability to bond with other wine molecules, leading to less-tannic yet smoother wines.

Oxygen transference through glass and stopper is also an integral component of wine aging, as its ingress into the wine can depend on several variables including tightness of stopper, components’ oxidation rates and storage conditions. This is especially relevant when dealing with rose wines or older vintages which may be susceptible to oxidation; adding preservatives (usually sulfur dioxide) may help preserve them longer without degradation occurring over time.


Blending is the final step in turning grapes into wine, using their unique characteristics from different varietals to craft something far superior than any single varietal could achieve. Blending requires understanding which wines to combine with how much of each, using different barrels with toasting levels or aging periods and ageing periods to add nuanced flavors for an overall better wine product.

Most commercial wines are blends, as individual wines may not possess the ideal combination of flavor, tannins, acidity and color – or can even suffer from poor vintages – making blending an effective way to compensate.

Winemakers begin with a basic blend and then gradually introduce percentages from other varieties until achieving desired results. Even subtle adjustments can drastically change a wine’s profile and alter its profile significantly.

Each grape variety imparts its own set of aroma compounds that interact to give wine its distinctive aromatic complexity. It is an intricate process requiring skill and knowledge of chemistry.

Blending is an inexact science; much of its elements can be quantifiable and objectively evaluated. For instance, when two wines are tested for tartaric acid content independently and blended together they tend to exhibit lower tartaric percentage than either individual varietals alone.


Filtration is a crucial process in wine making that is used to enhance clarity, consistency and stability, reduce oxidative damage and remove certain undesirable flavors. Membranes filters are widely acclaimed for their ability to remove yeasts, bacteria and other unwanted particles from wine.

As wine ages, particles such as dead yeast cells and grape skin fragments settle to the bottom, giving it an unattractive cloudy appearance. Fining can remove these deposits through physical binding using egg whites, isinglass or bentonite clay to physically bind with and precipitate out any unwanted elements from within it.

However, too loose of a filtering process may lead to cloudy wine as larger solids pass through unchecked. Therefore, prior to filtering it is recommended to conduct a bubble point test – measuring how much pressure a filter can withstand before gas diffusion becomes impeded – this measures its pores size and can help determine if or not your filter is appropriate.