Harvest Prep
You’ve heard of spring cleaning, but at this time of year, at least in the northern hemisphere, wineries are working on pre-harvest cleaning.
Tanks are sterilized and readied for juice to be fermented into wine. New barrels are unwrapped and set up. Older barrels are checked for leaks. Equipment is fired up, gas tanks are filled, checklists are completed.
Ideally, everything is done to alleviate any disorder and to prepare for predictable challenges that might be met. Inevitably during harvest there will always be something unexpected that arises, necessitating a pivot or adjustment.
Not enough grapes arrive. Too many grapes arrive. Grapes arrive early, or late. Something breaks down. It is a time of year when all hands are on deck. Cleaning, scrubbing, moving. Wash, rinse, repeat. Over and over. Until it’s done. The days are long and sticky and in these parts, cold.
Before the grapes arrive and while the wine is being prepared, winemakers are making critical decisions as to when to harvest.
Wait too long and you risk the potential for bad weather. Or worse, falling acidity in the grapes. Pick too early and the acids could be too high with not enough sugar accumulated, resulting in underripe grapes that can lend to unsavoury aromas and flavours.
For example, if cabernet sauvignon is not ripe enough, it will have notes of green bell pepper and tomato leaf. When overripe and picked too late, you can expect notes of vinegar or a caramelized smell with a distinct nutty, jam-like, or bruised-apple aroma. Finding the right time and balance is key.
The ideal time depends on each winemaker, and what kind of wine is to be made.
Testing is done by picking a sampling of grapes from around the vineyard and measuring for sugar level and total acid.
Total acid refers to Titratable Acidity (TA), the measure of all the acids present, primarily tartaric and malic acid. While pH measures the strength of acidity, TA provides a quantity of the total acids. Winemakers use TA along with Brix, a measurement for sugar, and pH to determine the precise harvest time, as TA typically decreases and pH increases during ripening. The ideal TA range for wine grapes depends on the grape and the style of wine they are destined for.
The grape variety itself and climate play a role too. Some grapes are naturally more acidic, such as chardonnay, while others like gewurztraminer, are less acidic, so finding a balance is key to picking time.
In warmer climates like California, a winemaker will sacrifice acids for ripeness. They want the grapes as ripe as possible so that the wines can have a higher alcohol content, and feel richer and fuller in the mouth.
In other places such as Champagne, they will pick early as acid is key for traditional method sparkling wines. Too ripe and the wines will lack the delicate finesse coveted by sparkling wine lovers.
Whatever the wine, you can bet winemakers across the Northern hemisphere are all watching the weather with bated breath this time of year.