It’s about time we got back to some science. A while back, I challenged you to compare two gourmet chocolate bars. I’m not sure how many of you actually did it, but if you did, you should have seen a small example of how terroir effects every type of food and drink, not just wine. A question has been nagging me since the chocolate challenge, and I’m really excited to finally have the time to address it. Together we have looked into the concept of terroir, particularly in how it affects a wines composition and palate, but I’ve never taken the time to discern whether or not it impacts color in the glass.
We already know that regional geological and geographical aspects of terroir directly impact flavor and sugar concentration, so my goal is to determine if those same aspects influence the color of the final product.
A wines, including its color, is created by various chemical compounds and reactions along its way from graft to table. The primary compound responsible for the color of a wine is flavanoids which are a type of polyphenol found in the skins and seeds (otherwise known as the solids) of grapes. This compound is extracted in the maceration process prior to fermentation but immediately succeeding the initial pressing of the grapes. Just as with the sugars and minerals which make up the flavor composition of a wine, the ratio of flavanoids to water impacts the outcome of the wine. If the berries are small and have matured in periods of well-defined stress (limited access to water and vast times in high day time temperatures with cool evenings) the fruit juice concentration ratios will be ideal and the color of the wine will be rich and true to varietal. However, if the region where the vines are grown is subject to too much rain, not enough heat, or too little time on the vine, the fruit will be overly saturated with water and the juice will be pale in tone and hue.
That being said, it is obvious to me that terroir (climate and location) have a massive impact on a wines initial color.
Just within Virginia I can give you an impressive example. If you compare the Reserve Cabernet Sauvignon wines from Mt. Vale Vineyard in Galax, Virginia and Barboursville Vineyard near Charlottesville, Virginia you can see the color difference impacted by the terroir. Galax has a cooler climate with a higher amount of rain, and though the vineyard recognizes that their mountain side vineyards cool climate is not appropriate to grow Cabernet Sauvignon, a notoriously complicated grape to grow, they do purchase fruit from in their immediate vicinity. The color of the Mt. Vale Cabernet Sauvignon is visibly thinner than that of Barboursville or other Monticello AVA cabernets in part due to the rain and the age of the vines. Even with strict pruning regimens to reduce leaf water potential (the leafs ability to absorb water to nourish the fruit) they simply get too much water and not enough hot days for highly concentrated phenols in the juice and skins of the fruits.
In the Monticello region, during the primary growing seasons of April to October there is a temperature differential of at least 20 degrees reaching highs in the 100’s during the peak of summer with lows potentially in the 50’s. This allows the fruit to sufficiently concentrate over night and the region receives approximately 47.7 inches of rain a year. In the Southwestern Region of Virginia there is also at least a 20 degree differential between day and night but their over all temperatures are cooler by at least 20 degrees which doesn’t provide the same ripening potential. Also, while they receive only 43 inches of rain a year they do receive significantly more snow fall than the Monticello ava.
If you were to look at these patterns on a country wide scale, comparing the reduced rain fall and stark day to night temperature differential in the desert of California to the weather patterns in the Monticello AVA of Virginia, you would estimate that California wines would have a massively more consistent and more difficult habitat resulting in more concentrated phenols and flavanoids which are responsible for color in red and white wines.
A few points I would like to note:
- There are many ways for a viticulturist (the human in charge of the plants in the vineyard) to direct the quality of the fruit and thus the quality in the glass. Some of these include irrigation management, fertilizing, trellising, pruning, harvest time, and micro-climate management)
- After the fruits have been harvested, there are many ways the enologist (the person responsible for fermentation, blending, and aging the wines) to direct the color and quality of the wine on the table as well. Some of these methods include barrel aging, extracting, and adding enzymes or other fruit derivatives to manually improve the color and quality during or after maceration.
- Because of all the many methods available to improve the quality of wine derived from low quality fruit, it could be difficult to see any terroir driven effects once a wine hits the table. I do however endlessly encourage wine drinkers and other consumers to ask winemakers and wine growers questions about their processing and manufacturing.
- Flavanoids are found primarily in wine skins and seeds, since white wines do not spend time macerating with the skins and seeds to gain color, flavanoids do not impact white wines as much, if at all. White wine colors tend to come primarily from natural fruit juice colors, oak fermentation, and oxidation over time.
Because terroir is the cumulative impact of regional soil compositions, weather patterns, and other local affects, it is safe to assume that a red wine from Virginia would look just as different from a French wine as it would smell. Along the same lines, with all that I have learned about the terroir effect in relation to the color of vitis vinifera (wine making grapes), I can only assume these same concepts come into play with other terroir driven edibles like chocolate, coffee, and peppers. I grow more curious about the mechanics of wine making with each post that I research, so please ask me questions. As for the question of terroir, I will see if I can find some examples for Wednesday, and I will try to show you examples in wine as well! Keep an eye out for news coming this week!