by Gary Twining
Most consumers think that blending two or more wines together only happens with Sherry, Port and Champagne – or they expect the “blend” to be explicitly stated on the label, such as Cabernet Sauvignon/Merlot. However, every wine is a product of some type of blending. The process happens either in the vineyard, the cellar or as the wine is aging.
Blending ensures the winery will produce a large enough volume to market the wine. Some wines that are exclusively single vineyard, single varietal (i.e., single grape), or single barrel products, but wines released in any type of quantity have to be a product of some type of blending to ensure that a market share can be built for the brand.
Blending also helps to keep the wine of any specific release consistent from bottle to bottle. There are many variations in the raw fruit that occur as part of winemaking, and the winemaker can’t harvest all fruit with exactly the same amounts of each component. Different parts of the vineyard and even sides of the vine ripen at different rates. The fruit from large sites can’t be picked at exactly the same moment. Fermentation of the same fruit in different vats does not yield exactly the same result. Barrel aging also offers various tannin and extractive levels because oak is a natural product. Without blending, any of these factors could change the tastes of wines made at the same time. Blending is particularly vital for releases that are not vintage or varietally labeled, for consistency of taste over the deviations of fruit character and weather inconsistencies.
Blending also can improve a wine’s quality by altering the levels of certain components (sugar, acid, alcohol, color), length (how long the taste remains in your mouth after you swallow), complexity and texture as desired by the winemaker.
Perhaps the simplest process is blending a number of barrels or vats of one varietal like Chardonnay. The wines can be run into a large vat (being protected against oxidation) and the wines are given time to marry. The new blend will be stabilized (instabilities can occur when blending two stable wines) and prepared for bottling.
Blending is not always as simple as mixing two huge vats of wine together, however. The wines are usually tasted and analyzed, excluding those of lesser quality, and blending trials are set up to examine potential blends in small amounts. The most appropriated blends are selected and given a short time to rest in the bottle, then examined to see if their flavors changed.
Specific colors, flavors and component levels might be deficient in any wine. Determining what can be done to improve the balance of those factors will determine which wines will be blended, why, and in what proportions.
Blending is not an exact science. However, if the winemaker knows all the scientifically measurable features of the wines being blended, it will simplify the process of enhancement and improvement. For example, knowing the level of acidity in two wines can lead to a prediction of their blended acidity level. Measuring the levels of basic components speeds getting close to the desired color and flavor levels, which can then be tweaked slightly.
Try doing your own blending trials using wines of similar styles and characters. It will help you learn about blending and you will gain greater appreciation of the winemaker’s skill.
What is blended and when
In the vineyard – Blending might be determined by the timing of picking the grapes, fruit ripeness levels/ different vineyard soil types, vine rows, vine clones/selections/varietals/age, and regions.
In the cellar – Juice or wines from different press runs are blended, or wines of various fermentation temperatures/containers/materials, those fermented with different yeasts (native and selected strains) or yeast contact time, malolactic levels, extraction techniques (punch down/submerged cap/roto-fermenter/treading/pump over/rack and return), and amounts of skin contact before, during and after fermentation
During maturation – Wines produced with filtration and fining differences, time and aging container materials (levels of tannin in the wine and barrels), vintages, and final component/additive levels (sulfur, acidity, volatile acidity, residual sweetness, tannin, color, aroma, flavor, length of finish).