As a general rule, winemakers don’t like to gamble. 

When they blend varietals, they generally ferment each grape separately, then carefully mix the wines to achieve a desired profile. 

But some vintners adopt a more carefree approach: crush a medley of grape varietals together, let them ferment in the same container, and see what results. 

The method, called co-fermentation, is based on an idea – at once old and new – that technical mastery can’t always match, whether in beauty or creativity, nature itself.

Yet, until recently, the practice was rare.

More on that in a moment. But first… Why is the Partnership so obsessed with altitude?

This week, Julien takes us through the many ways altitude affects wine & winemaking… from cool mountain temperatures… how hot days interact with cold nights… benefits and drawbacks of strong UV radiation (and why the levels seen in the Andes are so rare)… and how all this combines to make wines we love…

Does This Ancient Science Produce Better Wine? Continued

Wine writers like to call co-fermentation the “ancient science.”

In its earliest form, co-fermentation was a technique that small time village winemakers employed by accident.

They’d go out to the field, harvest whatever was growing, and press it into wine with no attention paid to what it was or whether it was even all the same varietal. The point was to make hooch.

(Such a wine would be called a “field blend” today.)

Since then, winemaking has become a far more regulated process.

If you’re in the business of selling wine, it helps to know that what you’re bringing to market is what the market wants.

Since the 1980s, the market has mostly wanted “big but balanced” red wines in the Bordeaux/Napa style, as favored by the critic Robert Parker.

Those big reds – often blends – need just the right grapes, from just the right plots, mixed just so, at the right time, with filtration and additives as necessary (fining, balancing acidity, etc.).

In short, you can’t just throw them together and hope.

That, plus a general shift towards a more technical winemaking style born of the UC Davis school in the 1970s has made co-fermentation rare. 

Up until recently, the practice was largely confined to the Côte Rôtie, at the northern end of the Rhone Valley, where they ferment a bit of viognier (a white grape) in their syrah (a red grape) to bring out floral notes.

And yet, some winemakers maintain that co-fermentation produces superior flavor and aroma to a controlled, technical approach.

Science may agree. A study from 2011 found that co-fermented wines have “a more complex chemical profile.”

In any case, the practice seems to be catching on again, particularly among the low intervention set (what could be more natural than just letting the grapes sort it all out?). Wineries out in California are throwing bunches of chardonnay or sémillon (the sweet sauternes grape) into their merlot must.

Even in the Calchaquí the practice has begun. An ancient science for an ancient land. 

Until next time,

The Wine Explorer

Bonner Private Wine Partnership