Picking When Ripe -The Gestation of a Grape?


If you ask me what I believe in, I’d have to say I believe in biology. That is, I believe things on this here planet work in biological systems. So I think about most aspects of life in biological terms. People often ask me how I determine when to pick grapes. This is an interesting question. The decision to pick, along with making blends, are the two most important functions that distinguish a winemaker from a process manager at a wine factory. Neither of these skills can be taught in a classroom but are gained only through experience. In determining when to pick, winemakers often talk about sugar, acid, and the balance between the two. Some folks talk about flavors. Some will even talk about physiological ripeness of the grape. What does all that mean exactly? How do they relate to the timing of harvesting grapes? And how does my biological lens aide me in my process?

Through twenty years of making wine, I have learned that merely looking at the numbers when analyzing a grape sample for sugar or acid levels is not enough information for me to decide when to pick. I need to see the vineyard’s progress: the changes in the actual fruit and in the vines themselves. I’ve often observed instances where the winemaker determines the pick based solely on numbers. Sadly, it seems, many winemakers don’t form a relationship or mental history with their vineyard sources so these solitary snapshots are all they have to go on. In my mind, this is the difference between a vineyard winemaker and a winery winemaker. That is why I favor estate grown winemaking. Throughout every vintage I build intimate knowledge of the vineyard. I live on it. I walk it almost every day during the growing season.

Determining when the grapes are ready is not just tasting for a specific flavor, though, it is tasting for the evolution of flavors as the grapes near perfect ripeness. That is why I cannot visit a vineyard once and determine when to pick. I would only have one reference point for that season. Sure it may have flavor but in terms of intensity and profile how does that compare to how it tasted last time I sampled? Each variety has its own distinct evolution in flavor. For Viognier I look for the passage from fresh floral to spicy floral aromas whereas with Pinot noir I look for the transition of flavor from fresh strawberry to the creamier texture of cherry. On top of that I try to gauge the persistence of flavor on my tongue and the quality and nature of the tannins in the skins and seeds.

But, tasting for the evolution of flavors is not the only factor I consider when determining when the grapes have reached their full potential and the fruit is ready to be picked. I also pay attention to physiological factors that reveal when the fruit is at its optimal ripeness and the seed is primed to be dispersed. The seed serves a biological function: the formation of the seed completes the process of reproduction. Among other features, I examine the seed color and texture, the color and translucency of the fruit, the feel of the grape clusters to the touch, the quality and nature of the grape’s pulp, the texture and structure of its skin, and the nature of the grape stem. The fleshy part of the grape, the fruit, is the plant’s vehicle for seed dispersal. Flavors, color and other factors develop during ripening to increase the likelihood of the seed’s dispersal. I feel that when physiological signs of fruit ripeness are optimal, the seed will also be at its ideal state, and the flavor development in the fruit should be at its apex. More time on the vine would result in flavor degradation as established by a biological determinant. Every year is different, though. It is basically a balancing act, a risk/benefit assessment best faced in a Zen state of mind but often fraught with indecision. Should I wait for more flavor at the expense of gaining too much sugar? More flavor at the risk of gaining overripe, mono-chromatic flavors?

The other source of information for determining when to pick is the vine itself. Will the vines crash before the fruit fully ripens or can the leaves hold on so we can eke out a bit more ripeness? Are the vines still metabolizing or are they shutting down and degrading the proteins in the fruit necessary for a healthy fermentation? Would waiting even help? What is the weather going to do? Is there rot in the vineyard? How has this vineyard block historically responded? Ack!

So the winemaker is like a day trader, letting her investment ride to reach maximum flavor until maximum payout is reached or the risk of detriment becomes too high to hold the fruit on the vine. In ideal years, a winemaker seeks perfection looking for maximum payout with little risk of market reversal. The fruit stays physiologically sound, the numbers are balanced and market downturns in the form of rain or other deleterious environmental conditions are scarce. In not so ideal years, the winemaker is forced to be much more diligent while deciding to wait for further ripeness, as the market can be much more volatile and the risk for a loss of investment are much greater. In those situations, if the vine gives me signs that it has done its biological job to maximize the conditions of its progeny, then I perceive that it is time to pick regardless of whether the sugar or acid levels are “ideal.” This is why I look at the fruit and the vine as a whole when considering a picking day. And with every growing season I learn more and build on past experiences.

I have been thinking about these things through this perspective since I am gestating my own progeny. With every kick and squirm in my expanding belly, I feel grateful that, unlike with grapes, we humans don’t have to look for the signs of when the baby is ready to make a decision about “when to pick.” You wouldn’t want to make a mistake and have an “over-ripe” baby, would you? Fortunately, though it is a bit unnerving for us, Mother Nature usually determines when the baby is ready. It would be nice if we could pick the due date, what the heck, why not the exact hour of his or her arrival to the outside world. I guess there are some things we can’t control, but as farmers we know this very well, especially when it comes to the weather. Thus, it is important to stay in tune with all the signs that nature gives us. There are times when you just perceive the right signals and everything falls into place. My impending due date looms in the very near future. As with that pick date, sometimes you just have to go with your gut feeling…but I may not schedule anything just in case it storms.

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