Residual sugar in Napa Valley cabernet sauvignons? It seems like a strange topic for a conversation, but it came up a number of times during three trips to Napa earlier this year, when I tasted the amazing 2012 and 2013 vintages.

One of the most memorable conversations was with the winemaker of Inglenook Vineyard, the Napa Valley winery of filmmaker Francis Ford Coppola. His winemaker, Philippe Bascaules, who worked at Château Margaux in Bordeaux before coming to Ingelnook a few years ago, lamented that some of the top-rated Napa reds were so high in residual sugar that it masked their true character and quality.

“Winemakers need to be more confident in their terroirs and make drier wines that reflect the fantastic quality of the region,” he said during a tasting of his outstanding 2011, 2012 and 2013 cabernet sauvignons. His reds were dry and structured, with the texture and mouthfeel of a top Bordeaux, yet with the purity of fruit you expect from a Napa red.

Indeed, serious winemakers, no matter where they are, need to respect themselves and their terroirs—and make wines that underline where they came from, instead of the hand that made them or some preconceived notion of what the market wants. Granted, this doesn’t have to be the case for inexpensive beverage wines that are akin to fast food. But bottles that are supposed to be special, and are often expensive, should be made in a relatively non-manipulative way. Residual sugar in what is supposed to be a dry red indicates otherwise.

The manipulation of such reds begins in the vineyards. Growers pick the grapes as late as possible to assure extreme ripeness, with high sugar content and ripe tannins. The grapes can be like raisins, which produce wines that are very high in alcohol, although winemakers may water down the musts in fermentation or de-alcoholise fresh wines. The fermentations stop, as the sugar is too high for the yeasts to convert everything into alcohol—so what’s left? Residual sugar. Wines are less stable with this residual sugar, so they need to be treated with products or filters.

Of course, the sugar is barely discernable for most palates. Some say the threshold is about 3g of sugar per litre (or just 3 per cent by volume) for a drinker to discover something slightly sweet. But it’s there, giving the wines body and a soft texture—or, as one Hollywood dinner partner called it, “those candy-styled sort of wines”.

Many of these sugar-coated reds have received high scores, mostly in American publications. The sugar and alcohol give the wines impact in tastings, and attract tasters with a sweet tooth. This style of red was popular in California from about 1994 to 2009, and in Australia, Argentina and Spain in the late 1990s and early 2000s.

But times have changed. For example, I have tasted at various wine shows in Australia over the past five years. Aussie winemakers on the tasting panels seem to despise “jammy wines” made from “dead fruit”. Today in Napa, the young winemakers shun those sweet reds of the past, too, making dry wines that reflect their unique soils and climates.

I’m happy the sugar-coated reds of the world are becoming a thing of the past, even though some old-school winemakers are still pushing the sweetness envelope. In the end, outstanding wine is about two things: drinkability and provenance.