Flavor Adjustments for Wine
An interesting article about adjusting the flavor profile in wines caught my attention last week. Since the Texas grape harvest is essentially done, and most of the fruit is in the process of being converted into wine, it seems like a good time to discuss various techniques used to adjust flavors in the 2018 vintage wines we will be enjoying in 2019-2020.
Producing good wine is not an accident. Skill, knowledge, experience, luck, not to mention quality grapes, all play important roles. Even though quality grapes or juice may be available, the optimum or preferred flavor profile may not result without the winemaker tweaking some things in the process. Below are some examples of the most common flavor characteristics that can be adjusted: alcohol strength, acid, tannin, oak, sweetness, fruit aromas and flavors, and body.
Adjusting alcohol content upwards is usually done right when fermentation begins by a process called chaptalization, the addition of sugar, honey or grape concentrate to the must. This most often happens when grapes with slightly lower sugar content are harvested and more alcohol is needed to make a balanced wine. Lowering alcohol content is more troublesome, but can be as simple as adding some water to high-sugar grape must. Unfortunately, this also dilutes the natural flavor components. Some high-tech procedures are available for lowering alcohol content, but these methods are expensive and specialized equipment is required. Blending wines with higher/lower alcohol levels is also a common method for adjusting alcohol. The best option is harvesting grapes at the “right” sugar content.
Acid is important to a wine’s structure, and to the way it tastes. Tartaric and malic acids are the primary natural acids in grapes. If a wine’s acidity is too low, it tastes flabby and flat. Too much acid makes a wine tart, and often unpleasant. So, balanced acidity is a key winemaking target. It is common in the hot, arid Texas climate for acid levels in ripe grapes to be lower than desired, requiring adjustment in the winemaking process. This usually involves the addition of tartaric acid at the beginning of fermentation to adjust the pH (free acid) to a more desirable level. Adding tartaric acid after fermentation is trickier, and may leave a tell-tale minerally flavor in the wine.
Reducing acidity is also possible, but not procedure often needed in Texas. Limited addition of potassium carbonate can reduce acid levels, similar to the way TUMS or other aids can lower stomach acids. This is a handy technique to have available and it usually does not cause a residual chalky taste in the wine.
Tannin naturally comes from grape skins, and provides astringency and tartness to wines, especially red wines that are fermented with the skins. Tannin can also be introduced to wines via contact with oak barrels, oak alternatives and even tannin powder added during fermentation. A common way of adjusting tannin is to add higher tannin content press wine fractions to free run fractions. This can also enhance overall color in a red wine. Establishing an optimum tannin level is important to creating a balanced wine that can age well. More about tannins can be found in a previous Carl’s Corner post (www.fourpointwine.com/blog What are Tannins in Wine?, 14-Sep-2018).
The flavoring of oak in wines has traditionally come from fermenting or aging in oak barrels. Oak barrels are expensive – American about $350-550 and French about $800-1,200 each. More often these days oak alternatives, chips, staves, or blocks to contact wine in tanks, are being used to simulate the flavors of aging in oak barrels at a lower cost. The aromas and flavors of butter, cream, vanilla, smoke, and cocoa that come from toasted oak can significantly enhance the flavors in a wine.
Sweetness, or sugar level, can be adjusted in several ways. A winemaker can stop a fermentation before yeast has completely converted natural grape sugars into alcohol. However, stopping a fermentation is not the easiest thing to do. Much easier is the addition of sugar or sweet grape concentrate to raise sugar content to a desirable level once fermentation is complete. Most sweet wines on the market today are created by post addition of a sweetener, followed by filtering and stabilization to prevent further fermentation in the bottle before consumption.
Fruit flavors can be added to wines, typically before bottling. Natural grape and other fruit concentrates are available, with or without sugar content. This is typically how wines like blackberry Merlot or peach Moscato are produced. Some flavoring products are designed to enhance the natural fruit aromas and flavors of the base wine should the winemaker desire.
One more adjustment can be made to build more body into a wine. This usually takes the form of glycerin addition to create a richer, thicker mouthfeel. This is not commonly done, but can be a helpful adjustment if a wine feels particularly thin.
Though not often mentioned or discussed, these behind the scenes flavor adjustments can help winemakers improve the quality of their wines, and make them more attractive to customers.
This post was adapted from an article in WineMaker magazine written by Steve Bader, digital online edition, September, 2018.