Harvest is the best of times and the worst of times, both in the winery and in the vineyard. I am sure you can imagine the emotional load is huge. This is the moment of fruition, when after nine months of carefully tending the vines we come to the natural conclusion of a bountiful harvest. Although that sentiment feels all warm and fuzzy there is a lot more angst in the harvest season than you would think. You see, there is so much at stake. The angst is simply – when to pick the grapes? The answer is obvious: you pick the grapes when they are ripe! So when is a grape ripe? And "ripe" here really should be followed by the question, “Ripe for what?” Ripeness for sparkling wine is not the same as ripeness for a rich, barrel-fermented Chardonnay. The next question is “How are you going to assess ripeness?” Do you stick with tradition and use your primary senses as winemakers have done over the centuries, carefully monitoring the sequential color changes, the gradual softening, the exhilarating development of aromatic complexity along with the taste of the skins and the seeds? Year upon year the experience and the tradition grow to create wines that are products of the local terrain or as the French like to call it the “terroir.”
In the place of knowledge acquired over centuries of experience that produce what are referred to as “old world” wines – France, Italy, Spain even South Africa.The modern-day approach is not to rely on traditional experience and to adopt practices that in contrast to the old world are referred to as “new world wines” from the United States, South America, Australia and New Zealand. In the new world, emphasis is on objective measures of grape ripeness using more scientific and technologically advanced equipment that accurately measure basic chemistries like sugar and acid as well as even more complex substances like phenols and anthocyanin, glycosides and amino acids.
Wine growers and winemakers alike make a distinction between what is called “chemical ripeness” and “physiologic ripeness.” In the old world, typically as a grape matures over time the chemistries accumulate at the same time as the more complex components like tannins mature. There are circumstances however, when a grape can be chemically mature before it reaches physiologic ripeness. The perfect example was in the early days of wine growing in Chile with a grape variety called Carmenere. Originally labeled as Merlot, Carmenere was grown at altitude rather like Argentina where there because of elevation sunlight is more and temperatures are much cooler. Under those conditions grapes ripen very rapidly that is they develop sugar and acid levels that in Europe (old world) would only occur after the fruit has ripened slowly over many months. In the old world the chemical ripeness is equal to the physiologic ripeness in the new world the fruit is chemically ripe but physiologically under ripe, all those complex chemicals have not had time to mature and that is not good for wine making. So in the early days of Carmenere from Chile the wines were immature with harsh young tannins and way too much acidity primarily because of the mismatch between chemical and physiologic ripeness.
There are of course other ways than measuring chemical components of the grape to assess maturity that is the readiness to pick and that is using Sensory Berry Analysis a semi-objective way scoring grape maturity that was first developed at the University of Montpelier in France.
In this method, the ripeness characteristics of the grape are assigned a score. For example, a grape that is hard and difficult to squeeze is given a low score and a grape that is soft and mushy is given a high score. The characteristics depending whether the grapes are black or white include the softness or turgor of the grape, the nature of the skins, the pulp and the seeds, as the grapes mature so the score increases. Like most scoring systems there is a long version and a more quick and ready one that can be used in the field. Like all scoring systems it has its drawbacks but for me it is the systematic evaluation of each component of the grape that is the system’s greatest value and like any instrument of measurement it is only as good as the discipline with which the method is used.
This type of qualitative sensory analysis is used a lot in the wine industry mainly because it is so hard to actually measure quality. Incidentally, Robert Parker came to fame by adopting a scoring system for wine quality. To many peoples’ chagrin his scoring system caught on not because if its accuracy but because of its convenience.
But we have to bear in mind the limitations of any scoring system that potentially shortcuts to good, old-fashioned observation.
At last by combing observational skills (art) with objective (science) measures of grape quality can we can at last decide if the grapes are ready to pick. So then all we have to do is work out how we are going to bring the fruit, in remember most vineyards mature at the same rate so when it is time to pick so is everyone else. And by the way where is that hurricane in the Gulf of Mexico? And do we have enough tank space in the winery to process the fruit?