Shatter and What it Means
by Wendy VanHatten
Wine terms can be confusing.
Have you ever heard a winemaker or a grower talk about shatter?
Shatter is one of those wine terms that doesn’t sound like what it might mean. When talking about a vineyard, and the term shatter is used, it almost sounds like the grapes broke. I mean, that’s what happens when my plates shatter. Right?
That’s not quite the same. Shatter, in the context of a vineyard, refers to the phenomenon where a grape cluster fails to develop into maturity. What causes it? Usually, climate conditions create a failure to pollinate.
The French call it coulure. The weather could be too cold, or too cloudy, or too hot at the wrong time. The flowers on the grape vine won’t open. They’ll stay closed and then can’t be pollinated. As in all fruits, unpollinated flowers don’t turn into fruit. In this case, grapes.
Technically, I’m told the cause of shatter has to do with carbohydrate preservation. A grapevine that has low sugar (carbohydrate) levels will conserve those levels. This denies the flower and in turn the grape, for the good of the overall plant. The plant lives to produce another year. Just not this year.
Malbec is prone to shatter and can even create a crisis for a vineyard. Do they recover? They do, but sometimes not easily.
That’s why growers will use varietals which are not as susceptible to shatter as Malbec. They also won’t over-prune the vines, leaving more leaves to produce carbohydrates in the plant.
Never heard of shatter? Many of us haven’t. You probably don’t even realize it might be one of the reasons your favorite wine is slightly more scarce one year, or you pay a higher price for it.
Now you know…