Generations of gourmands and sommeliers agree that olive oil and red wine pair well together; and now a new study by researchers at the University of Bordeaux has established the scientific link between your favorite full-bodied red and "liquid gold." In March, the American Chemical Society published a report from French researchers that examined the interactions of lipids and tannins, and their influence on sensory perception of wine.
Tannins are the phenolic compounds found in wine that are derived from grape skins and stems. They provide that mouth-coating feel of say, a nice Aglianico, and are astringent by nature. This bitter taste is an evolutionary trait common in plants and the researchers sought to better understand the effects of tannins on the stability of lipids, specifically those found in olive oil.
Scientists began by adding a grape tannin, catechin, to an emulsion made up of olive oil, water, and a phospholipid emulsifier and closely monitoring the results with optical and electron microscopes. Initial observations indicated that the presence of the grape tannin caused larger oil droplets to form in the emulsion.
In the second phase of the study, researchers recruited volunteers for a sensory evaluation, using oils commonly found in foods, including olive, grapeseed, and canola oil. Volunteers were asked to taste a variety of tannin solutions of varying strength, either with or without an accompanying sample of oil, and rate their perceptions of the tannins. The scientists found that the greatest effect on the tannin perception was produced in concert with olive oil; causing the subjects to rate the solution as "fruity" rather than "bitter." This led the researchers to conclude that the interaction of tannins and oils during consumption makes oils less likely to bind to the proteins found in saliva, which produces the astringent taste.
We asked wine writer Alice Feiring about the research, and she points out that not all tannins are bitter or astringent. “Some tannins are sweet. Some are very ripe. Some are harsh and edgy. But if there's tannin there's texture. The beauty of olive oil is that it delivers the flavor of food. In the end, when olive oil is used in the cooking, a beautiful wine pairing, whether white, red, rose, or amber, is not far off."