Spring Has Sprung
Spring – when everything is abloom, allergies are running rampant, and growth start in the vineyards. The vines have been sitting dormant over winter, storing energy for the next harvest that will give us delicious wines! It’s both a scary and hopeful time for vineyard managers and winemakers. As the buds pop through there is always that risk of deep frost which will stifle or even kill nascent growth. In some cases, a hard frost will completely destroy the vines, as buds contain water, and freezing that will cause the cell walls to burst. It’s a nerve-wracking time for vintners and numerous measures are taken to combat this.
There are essentially two kinds of frost: advection and radiation. As we all know, cold air rolls downhill. The former occurs when temperatures drop below freezing. Radiation happens mostly on clear nights, when warm air from the ground rises, creating an inversion layer. On sloping lands, frost rolls into lower lying land creating dangerous and deleterious frost pockets. Early in the mornings, this kind of cold is sufficient to doom the new shoots.
If you travel through wine countries anywhere, you’ll often see smudge pots or bougies (French for candles) or even large fans. With smudge pots, once the threat of frost is imminent, these are light and hopefully the rising smoke will deter lower temperatures once this tenuous cloud cover is formed. Sometimes, leaves or hay/straw piles are light in the middle of the vineyards to create this protective blanket.
It doesn’t seem to make sense, but some vineyards will actually spray water over the vines right before a frost occurs. This creates a layer of ice on the shoots, and as the liquid freezes, it creates heat and protects the tender buds.
Some vineyard owners will even take to the air in helicopters to disturb the cold air, and even hopefully bring warm air back towards ground. Using ground-based sensors, helicopter pilots will fly over specific sections of vineyards a couple of hours before sunrise when the frost is at its peak. Helicopters take the place of massive fans which do pretty much the same thing, though some regions which are deemed of great natural beauty, might not allow 30-50’ high metallic contraptions.
So… now the threat of frost has passed (though IS always the threat of hail) and with it, new leaves are bursting forth. And shortly after, tendrils soar skyward, looking for anything to hold onto and pull the vines toward that life-giving sun. most vineyards will have already established a trellis system for the vines to grab and start spreading horizontally. Now, that magical time of primordial grape growth begins. As the tiny caps that accompanied the baby grapes fall off , there is a flowering stage allowing insects to pollinate and manifest pollinated grapes. Inside these grapes are seeds. This is the signal for the leaves to send sugar into the grapes and initiate a growth spurt.
For almost two months, as the grapes undergo cell division and growth, malic and tartaric acids, among others, form inside the grapes, while tannins are present in both the skins and seeds. During this time, there is very little actual sugar production.
Veraison! This is when grapes start to turn color. They add glucose and sugar (also called Brix) from the leaves into the actual grapes, and the malic acid levels decrease. As the grape clusters darken (in red wines especially) they form a more distinctive appearance against the greenery. Inside the grapes, phenolic compounds are forming and the skins tend to get a little thinner.
And then? Onto harvest and the madness that ensues as vineyard managers work furiously to get grapes in at exactly the desired Brix. Sometimes, a row of vines might be only partially harvested, contingent upon the sugar levels at each section of the vines.
But lets’ get back to Spring. As the vineyards start to blossom, so does life in general. Baby birds are nesting and chirping, butterflies and moths start to emerge from their cocoons, animals of all sorts are coming into the verdant and lush world following the dormancy of winter. So what’s on the menu for breakfast, lunch and dinner mommybird? Well, let’s see, those new fresh grapes over there look good!
Vineyard management is not just about helping grapes grow. There needs to be a level of protection. How DO vineyard managers prevent the multitude of scavengers intent on feeding themselves and their young? It’s a constant battle. First, fencing against deer and wild pigs is a great deterrent, but how about those airborne and voracious boids or rats and voles and their delightful cousins moles? Some have turned to birds of prey, such as owls or hawks, building nesting boxes at various locations around the vineyards. If there’s an incessant invasion of starlings , sparrows or such, then falconers will come by for a few days. The mere sight of a well-trained raptor soaring through the sky will scare a flock of marauding birds away immediately. Who wants to be lunch? Not me!
And owls? Beyond the lovely sounds they make, they can be exceptional predators. One owl can devour as much as 2,000 rodents a year.
Sometimes, one might hear shotgun or cannons booming in vineyards, scaring away birds. That tends to not work, as for some birds, it’s akin to the Pavlonian response. When the big booms are heard, it’s a signal that grapes are ripe and ready! And kites flying in the air? Not really effective. Same as plastic owls – basically ineffective, but they certainly make pretty ornaments…
So… enjoy Spring until Summer arrives. Don’t forget to support your local small wineries – they tend to create much nicer wines and besides, it’s good for local economies! And don’t forget to drink wine as often as possible (maybe not for breakfast) – it’s good for the soul and body!
