Zinfandel

The choice here is to use them or not. California’s Zinfandel producers frequently label their wines as “old vines,” “ancient vines,” and “heritage vines.”  Since none of these terms are legally controlled by the TTB, they mean whatever the producer decides. Over 50 years of age is commonly accepted, although some winemakers scoff and suggest at least 80, while others may dip a low as 30. 

What it does

Old vines produce lower yields, which equate to more concentrated fruit and less of it. 

Comment

The organoleptic results are always worth it -- greater concentration, deeper and richer flavors, and mouth volume. But the cost of farming and amount of harvested fruit per vine and per acre/hectare may not be. It is a personal and emotional decision, along with a commercial one.

Leave either the pre-fermented juice or post-fermentation wine in contact with the grape skins.

What it does

As flavors, tannins and color derive entirely from the skins, macerating with skins allows the winemaker to pull out the desired amount of same by choosing how long and when (pre- or post-alcoholic fermentation) to do so. 

Comment

Pre-fermentation maceration is common with Zinfandel and is primarily implemented to enhance pigmentation and soften tannins. Several winemakers retain some whole clusters, while others do no crushing, instead letting the fruit ferment in a semi-carbonic style.

What it does

Proponents of wild yeast embrace the unique flavors coming from the “place,” including savory and matchstick-like aromas that many love and associate with minimal intervention. Cultivated yeasts are more predictable and can be selected/customized to contribute specific flavors and aromas.

Comment

Some winemakers blend the two, sometimes starting with native yeast, reserving use of commercial yeast only if something does not go right (e.g. fixing a stuck fermentation). That said, with Zinfandel, it’s most common to work with commercial yeasts, with winemakers arguing that they need yeasts that can handle Zinfandel’s high alcohol and high acidity and can ferment at cool temperatures, quickly and thoroughly.

The wood employed for most wine barrels, used for aging the wine or actual fermentation of the wine in the barrel. Barrel decisions include the type of wood, the amount of toast (when the staves of the barrels are bent over an open flame), size (smaller = higher ratio of wood to wine = stronger oak influence) and the age of the barrels. 

What it does

• Chocolate, mocha, and vanilla flavors that many identify with Zinfandel come not from the grape but from oak aging.
• Heavily toasted barrels impart more intense roasted flavors (caramel, molasses, toffee, coffee and burnt sugar).
• Oak bestows a waxy, velvety texture and can add a perceived sweetness to the wine. 
• New oak contributes much more flavor than older, previously used oak which, depending on the wine and grapes, may be a better choice. 
• Small (barrique-size) barrel fermentation at warmer temperatures than those in stainless steel and over shorter increments of time also imparts a richer, smoother texture to the wine. 

Comment

Today, there is a movement towards keeping the oak in check, i.e. minimizing “over-oaking,” or even using no oak at all. Many vintners mature their Zinfandel in a combination of American and French oak barrels, although there remains a camp that prefers uniquely American wood for its hint of baking spice sweetness, and a few winemakers use older Bourbon barrels for their charred vanilla caramel character.

The vintner's practice of working with the tannin, minimizing, or maximizing its presence in the wine. Tannins can be maximized through letting the wine spend extended time on the grape skins (which also adds color) both before and after fermentation. 

What it does

Controls texture and mouthfeel, and mitigates bitter, astringent elements, flavor-wise and tactilely.

Comment

Tannins can be minimized by cutting back on maceration, or through a very gentle filtration. To soften hard tannins, vintners are increasingly turning to a process called micro-oxygenation, bringing out the bright character of the fruit and adding a rich mouthfeel. Left unchecked, Zinfandel tannins can be green, abrasive, and unpleasant. Cold soaking and shorter macerations are key, as well as chasing that balanced ripeness in the vineyard. Underripe fruit will lead to hard green tannins.

As noted above, a Zinfandel vineyard may indeed be a composite of Zinfandel and other grapes, as in a “mixed blacks” wine. Occasionally, these wines may fall below 85% variety and carry a proprietary name instead. 

What it does

Adds greater diversity of flavor and an added dimension of complexity.

Comment

Blends result in different styles of wine. Increasing the proportions of other grapes can augment Zinfandel’s profile at times, adding nuanced flavors from the other varieties.