Wine, in its most essential form, is a combination of flavor and mouthfeel. While there are several ways we can shape a wine’s mouthfeel, there are very limited controls for which specific flavors result in a finished wine. Those seeking flavor concentration may lower yields, and those seeking fewer pyrazines may leaf thin and extend hang time, but at the end of the day, what is most important is how a wine’s flavors integrate into its mouthfeel. 

Flavor
One of the key properties of virtually every flavor in wine is hydrophobicity, or the tendency to repel water. To put it simply, water is polar, and flavors are non-polar. They require alcohol as a solvent to remain in solution, which is one reason why de-alcoholized wines lose flavor before making it to the consumer. To better understand how hydrophobic flavors are, we refer to their partition coefficients (Log P) which range from a scale of -3 (very hydrophilic) to +10 (extremely hydrophobic) (Cumming et al 2017). A decrease in the partition coefficient will increase the concentration of the aroma in the headspace at equilibrium. A good example of this is rotundone (black pepper) in grapes like Syrah, which is very hydrophobic (Log P = 4.04) and often easier to taste than smell because it is binding to the phenolics in wine. As you will see in the chart below, just about every wine flavor has a positive Log P value, indicating their degree of hydrophobicity. 

Mouthfeel
Like flavors, tannins are hydrophobic and can have varying degrees depending on their oxidation state. Tannin stickiness is a measure of hydrophobicity made by passing wine through a hydrophobic HPLC column. The more hydrophobic tannins are, the more actively they bind to your salivary protein as well as aromas. This phenomenon also extends to non-macerated white, sparkling, and rose wines because iron-reactive phenolic acids like gallic acid are also hydrophobic and extract readily from grape pulp. This means the Van Der Waals interactions between these compounds influence general aromatic expressiveness when phenolics in wine are increasingly abundant and hydrophobic. How winemakers use key variables like temperature, oxidation, and maceration to integrate flavor into mouthfeel is critical to balancing this effect. 

Matrix
In wine, the two most important aroma suppressants are alcohol and tannins. The effect of alcohol suppression can be observed with a single wine in your glass over the course of an evening. Alcohol will slowly dissipate from the glass shifting the matrix and allowing the aromas to “open up”. Tannins, depending on their activity, can be significantly more stubborn. Strong aroma suppression is often observed in highly extracted wines made from concentrated grapes. 

Temperature & Oxidation
The key variables to managing this are temperature and oxidation, both in the vineyard and the cellar. Wines from cooler climates are often more closed while wines from hotter climate wines are more expressive. This is because heat and light accelerate the oxidation of phenolics in wine and decrease their hydrophobicity, thus making a harvest decision the first critical step to balancing flavor and mouthfeel. Once in the cellar, temperature plays a similar role, but oxidation occurs much slower because of limited exposure to light and air. The key mechanism instead is the polymerization of anthocyanins with tannins which decreases their activity and is increasingly favored at higher temperatures. The perfect example for this is flash detente which polymerizes an abundant amount of color and tannins from freshly crushed fruit in a matter of minutes. For most cases though, bound anthocyanins form over the course of weeks and months from the heat of primary and secondary fermentation. Facilitating this reaction naturally balances the aromatic expressiveness of your fruit.

Spoilage
When it comes to balancing flavors, it’s important to note that they also compete amongst themselves. Spoilage characteristics like Brettanomyces taint, ethyl acetate, and cork taint (TCA) can suppress fruity esters, a shift winemakers can detect even before identifying the spoilage aromas themselves. At these low levels, masked fruitiness may be perceived as increased complexity, but no winemaker encourages TCA because even at low levels it acts as a strong suppressor of our olfactory signals, clinging on our aroma and taste receptors and lingering on our palates (Takeuchi et al, 2013). Brettanomyces, on the other hand, can be a powerful tool and a positive flavor characteristic when incorporated carefully. 

Finally, it’s worth noting that compounds like acetic acid and carbonic acid (dissolved CO2) can enhance aroma volatility exemplifying the delicate balance a winemaker has to walk. This knowledge is exceptionally powerful when blending and shaping the different dimensions of your wine. In general, a moderate amount of flavor suppression is a good thing. Wines that are too expressive without the flavor concentration to match often jump out of the glass and can become dominated by a single characteristic. It is important to note that a wine chemistry profile is insufficient for determining which lots are more closed or open. Enological analysis lends insight into the quantity of compounds, and our palates add on the quality, giving us a holistic assessment of the wine no other instrument can provide. We, therefore, analyze the wine chemically and connect the dots organoleptically.