Alcohol, a necessary byproduct of fermenting ripe grapes, seems to have polarized the wine community these past few years. Most wine drinkers seem to like ripe flavors in wine, and don't mind if alcohol levels are higher, but a vocal minority wants to change that. There's even an organization of vintners in California, In Pursuit of Balance, which stumps for lower levels of alcohol.
This dichotomy jumped out at me when I read reactions to a recent study that reported consumer responses to Cabernet Sauvignons made at different alcohol levels. The study, conducted in Sydney, presented 104 consumers who drink red wine at least once a week with five different Cabernet Sauvignons harvested sequentially, with alcohol levels varying from 12 percent up to 15.5 percent, and asked them to give each wine a preference score on a scale of 0 to 9. Ratings for each of the five wines on nearly two dozen sensory attributes pertaining to appearance, aroma and palate were determined in a separate panel comprising 12 trained tasters from the Australian Wine Research Institute (AWRI).
"Consumer testing of the wines revealed that the lowest-alcohol wines (12 percent) were the least preferred and wines with ethanol concentration between 13 percent and 15.5 percent were equally liked by consumers," the study's abstract read.
The critical responses to the study's results were predictable. Those arguing for lower-alcohol wines pointed to one finding, that the tasters most liked wines at 13.6 percent alcohol. At a time in which 14-plus in red wines is common, 13.6 is a fairly modest number. However, there was no statistical difference between the preferences for wines at 13.6 percent and those at 14.2 and 15.5 percent, suggesting that higher alcohols don't really bother a majority of wine drinkers. Those arguing for ripeness noted that a relatively small minority of the tasters seemed to like the lowest-alcohol wines.
For some helpful interpretation, I contacted AWRI's Dr. Keren Bindon, who conducted the study.
First of all, she did not set out to measure alcohol preferences. She and her colleagues wanted to zero in on harvest time and grape maturity, looking at such things as tannins, color and flavor compounds in wines picked at various sugar levels (which, of course, translates into alcohol after fermentation). Then they asked consumer tasters their preferences.
The chemistry findings, which first appeared in a 2012 paper in Food Chemistry, are not surprising. Grapes from one vineyard in Langhorne Creek (a region in South Australia with a similar climate to Barossa and McLaren Vale) were picked at different times as they ripened in the 2010 vintage (a good vintage, neither too warm nor especially cool). The various sugar levels produced wines ranging from 12 percent to 15.5 percent alcohol. Analysis found significant changes as the grapes ripened, including more grape tannins and less seed tannins. Riper wines were more purple. In tasting the wines, a professional panel noted that green flavors diminished and fruit flavors increased. More complexity came from higher levels of volatile esters.
I am not surprised at the consumer tasting results, either, published online last month in Food Chemistry. In general, tasters liked the darker color, dark fruit flavors, fruit aftertaste and viscosity in the riper wines. They did not like the higher acidity and green notes in the wines made from earlier-picked grapes, and turned thumbs down on earthy and vegetal flavors.
That pretty much describes about 44 percent of the tasters, one of three distinct statistical groupings. Another 33 percent preferred the wines with the most color and density, even if they detected some heat from higher alcohols. But 23 percent preferred wines with redder colors, tart acidity and green aromas and flavors.
Remember, the wines in this test were designed to measure preferences for early-picked vs. later-picked grapes. Other studies focus on alcohol percentage by adjusting alcohol in wines made from fully ripe grapes. And we're talking about Cabernet Sauvignon here, a grape with flavors that change dramatically with ripeness.
"We were simply looking at ‘how low can you go?' in the vineyard by harvesting grapes at different ripeness stages (i.e. sugar)," Dr. Bindon said. "Consumers most likely did not reject the lower-alcohol wines based on alcohol content alone," she added. "There's a strong chance that they disliked other things in the lower-alcohol wines that were related to lower color, harsher acidity and green characters, rather than the lack of alcohol itself."
That squares with my view on ripening, that there is a point at which the grapes reach a stage where optimal flavors appear and the green flavors diminish. If the acid-to-sugar ratio isn't totally out of whack, that's usually where those vintners pick who make the most expressive wines. Letting the grapes hang for riper flavors can produce even more flavors and complexity, but can also go over the top, picking up dried-fruit character and unpleasant "heat" from the extra alcohol.
A new wave of vintners seeking more delicate styles, especially in California, can make beautifully elegant wines. I've enjoyed my share of them. But fearing too much alcohol, these vintners would rather pick early and err on the side of "green," convincing themselves this is what they like. I am left shaking my head. Dr. Bindon put it more scientifically. "For individual growers and producers there is a need to better understand how the flavor profile of their variety and site changes with ripening, and what the minimum harvest point is to get the right flavor spectrum for the style they plan to produce."
An acid test for low-alcohol wines, as it were, is the 2011 vintage in California and Oregon. Grapes struggled to get ripe in cold, wet weather. And yet, a surprising number of Oregon vintners managed to make really good Pinot Noirs, with ripe flavors and real depth, at alcohol levels as low as 12 percent. So it's possible, if your vineyard is in the right place and you have the patience.
For those of us tasting and choosing wines, whether we are writers, sommeliers, retailers or just friends advising friends, I say taste the wine before you decide if you like it. Don't reject it if the number on the label doesn't jibe with preconceived notions. Let's quit obsessing about alcohol.
This discussion dovetails with another trend I find disturbing. Some high-profile wine writers are suggesting that that they shouldn't have to taste blind, that it's unnecessary unless you have an agenda. I would submit that a preference for low-alcohol wines is an agenda. Just how much alcohol is present is not so obvious when you can't see the label.