Great moments in pedantry: How do you grow wine in a land without predictable seasons?

Winter is here. Which means it's time once again to start science-wanking the climate of George R.R. Martin's "Game of Thrones" series. Back in May, i09 had a great piece on possible astronomical explanations for Westeros' weird seasons, where Summer and Winter can each last a decade. The hard part (which prompted lots of great conversations here) is that the lengths of the seasons are apparently totally unpredictable. Here's an eight-year-long Summer. There's a Winter that lasts five years and another that lasts a generation. The implications for food storage, alone, are enough to drive one batty.

Word of Martin says this is magic. But it presents so many science-related questions that it's really, really fun to speculate about how you might explain the differences between that world and ours in purely naturalistic terms.

Now, at The Last Word on Nothing, Sean Treacy brings up a different sort of food-related problem that I'd not even considered while I was busy trying to figure out the volume of the average Westerosi grain silo. How do you grow wine grapes without predictable seasons?

... grapevines have a life cycle that depends on regular seasons. In winter, grapevines are dormant. Come spring they sprout leaves. As summer begins, they flower and tiny little grapes appear. Throughout the summer the grapes fill up with water, sugar and acid. The grapes are finally ready for picking in early autumn, then go back to sleep in winter. This cycle is why wineries can rely on a yearly grape yield. Obviously, in Westeros, something must be different about how grapes work.

But it turns out there is a real-world way to produce wine throughout an endless summer. São Francisco Valley is a wine-growing region in tropical Brazil that is only about 600 to 700 miles south of equator. Despite the constant warmth, they pump out two and sometimes three grape harvests a year. How? By depriving the vines of water and removing their leaves after every harvest, which forces them to hibernate. “They trick the plant into thinking it’s wintertime,” Busalacchi said.

The whole post is really interesting and you should read it. Who knew that the Arbor would lead me to be more educated about real-world booze?

Image: Wine, a Creative Commons Attribution (2.0) image from isante's photostream