To Dry Farm or Not? That is an Aesthetic Question

Irrigation usually enters wine discussions via viticultural practices, water policy, regional regulation, or sustainability. But irrigation also shapes what wine tastes like and what we mean when we say a wine expresses the place in which it was grown. Concentration, acidity, tannin development, freshness, alcohol, and texture are influenced by irrigation practices.

So irrigation has a lot to do with our aesthetic judgments about a wine.

Too much water can encourage the vines to produce foliage rather than sending nutrition to the grapes. It enlarges the berries and dilutes flavor concentration while increasing yields. But when the vines get too little water photosynthesis shuts down, ripening is delayed and the fruit lacks intensity. The romantic story told in tasting rooms of heroic vines suffering nobly beneath a blistering sun is misleading. Vines do not become expressive simply because they are miserable. Much depends on the site.

What matters for fruit quality is the kind and degree of stress a grower allows. Moderate water stress can slow the growth of foliage and concentrate flavor. But soil type, root depth, temperature, grape variety, and the vine’s age influence the outcome. A vine in deep clay soil will respond differently from one rooted in shallow gravel during a heat wave.

The fact that irrigation changes the sensory character of a wine, complicates familiar ideas about terroir. I recently had a dry farmer claim that irrigation as an intrusion, a human technology imposed on nature. He argued that dry farming reveals place while irrigation conceals it. But vineyards are already cultivated places. Growers decide what to plant, when to prune, how much fruit to drop, when to spray, and when to harvest. Water is another one of those decisions. The relevant question is how irrigation alters the expression of place, not whether it introduces human agency into an otherwise natural process.

But dry farmers do have a point. No doubt, heavy irrigation can produce high yields and blur distinctions between sites. It can snuff out seasonal variation making wine more predictable. and protect a commercial style from seasonal variation. But on the other hand, irrigation helps preserve acidity during extreme heat and allows fruit to ripen without dehydration. In a warming climate, irrigation often protects regional character and many regions have become so hot they really have no choice but to irrigate.

The question is whether water use responds intelligently to the site or forces the site to conform to a preset wine style. Does irrigation help the vine articulate the season, soil, and local climate? Or does it flatten those differences in pursuit of uniformity?

The problem with treating irrigation as an aesthetic question is that you really can’t tell from tasting whether the grapes were irrigated or not.  Only deep, site specific knowledge over time would enable that kind of discrimination. But we needn’t identify the cause of a sensory property for that cause to be aesthetically consequential.

So in a tasting note or an article about a wine, it’s worth noting if the grapes were dry farmed if you have that knowledge. It can be just as consequential as the oak program or the type of yeast used in fermentation.