While reading through The Wine Bible (aka what all winos swear by), a wonderful book by Karen MacNeil, we found ourselves fascinated by her excerpt titled “The Sex Life of Wine Grapes.” A title that would not only make any grade schooler giggle, but apparently also several twenty-something-year-olds too. So sit down and listen in children, let’s have “The Talk” about grapes.
Getting Down and Dirty
We might as well get right into it. Wild grapevines are either male or female (a small percentage are both, aka hermaphrodites). Wild male vines rely on the wind and insects to carry their pollen to nearby females to reproduce. Not ideal. It seems just so touch-and-go. The first people to cultivate vines thousands of years ago were actually quite smart. They realized that the male vines were barren without the female vines. Similarly, the female vines weren’t fruitful without the male vines. But by finding and selecting the small percentage of hermaphroditic vines to cultivate, they were in business. Today, cultivated grapevines are known as “perfect,” or hermaphroditic, meaning they have reproductive organs of both sexes and can self-pollinate. *Self-high-five*
Let’s Get Freaky
The grape life cycle begins in early spring with bud break when fresh, green shoots appear from the vines. In the northern hemisphere, bud break occurs in early spring. The southern hemisphere is about six months ahead, so bud break occurs in the fall. The shoots grow and grow and by May, flowers emerge from the once dormant vine. This is when things get super freaky in the vineyard.
These riled up, cultivated vines reproduce and pollinate, um…themselves (remember, both male and female parts). But vines are finicky freaks. They have to set the mood, and the moment has to be just right. We can’t put it into better words than Karen MacNeil when she said, “Too much wine? Forget it. A little chill in the air? The grapevines get a headache. Rain? Might as well take a cold shower.” That’s right, these grapevines need to be wooed – cue soft, smooth jazz, low light, candles, red wine … you get the idea. Only when the springtime air is perfectly calm and warm do these vines “do the deed.”
In a process called “flowering,” vines “de-flower” themselves. It’s going to get scientific for a moment, so bear with us as we explore the anatomy of the flower and learn that vine reproduction is oddly similar to human reproduction.
Doing the Deed
The grapevine flower has male and female parts, this we know. The male and female parts come of age together. They get acne, body hair, body odor (hello deodorant) and before long, the male wants to “sow his seeds.” #Puberty. And when the male parts want to release pollen, they do so through their mighty male “members”, aka their anthers. During pollination, the pollen sticks to the stigma (which is the female reproductive system) of the female vine, where it then travels into the ovary. Fertilization occurs once the sperm reaches the egg in the embryo sac. Yup. We’re still talking about flowers here.
Bundles of Joy
If all goes well, the fertilized flowers will turn into little baby berries called the “fruit set.” Awww! Grapes are born! These little bundles of joy ripen and grow during the early summer heat.
In July, grapes will change color. This is known as veraison. At this point, they’re nearly ready to be picked. They grow up so fast, *tear.*
Come fall, grapes are harvested and made into that good-good we all love. The winemaking process is a discussion we’ll save for another day. After all this action, grapevines are tired!
When temperatures drop, vines go into dormancy in the winter (don’t we all?) and rest up for next spring’s romp.
Sources: MacNeil, K. (2015). Wine Bible (2nd ed.). New York: Workman.
A Wine Story; SF Guide; Grape Berry Growth and Development; Extension.org