Wine and cheese pairing: I - the wines

My attention was called to a fascinating paper about the effects of pairing cheeses with wines, by a French group at the Centre des Sciences du Goût et de l’Alimentation, CNRS, INRA, Univ. Bourgogne, Franche-Comté, in Dijon, France.* In the next set of posts I will review this paper in detail, because it illustrates very clearly several points that I have been making in this blog.

First, about the wines themselves (am saving the discussion of cheese effects for the next post):

The four wines chosen for the study were Pacherenc, Sancerre, Bourgogne, and Madiran. Pacherenc is a sweet white wine, Sancerre is a dry one, Bourgogne is a Pinot Noir, and finally Madiran is a combination of Cabernet Sauvignon and Tannat grapes, with a high alcohol (15.2%) and tannin content. 

The consumers in the study—31 local Dijonnais who drank wine and ate cheese regularly, and who had participated in at least one previous sensory study—evaluated the wines initially and then after a second and a third sip. Evaluation consisted of a measure of liking and measures of sensory characteristics such as sweetness, astringency and sourness, as well as fruitiness.

These consumers definitely preferred the sweet Pacherenc wine to the others, and particularly to the Madiran—initial liking scores were double for the Pacherenc compared to the Madiran!  Furthermore, with each succeeding sip, liking for the Pacherenc remained the same or even increased slightly, while liking scores for the Madiran decreased significantly as astringency came to dominate the sensory impression. 

These results fall perfectly in line with the biology of sweetness and astringency: sweetness is perceived at the beginning of a sip and tends to fade a little bit as the sip progresses, but can return in full force with subsequent sips. By contrast, astringency takes a few “beats” to kick in before it starts to dominate a flavor profile.

The difference lies in the function of the receptors and their second messengers. In the case of sweetness, the process of perception involves a series of reactions in the taste cell that occur quite rapidly. The receptors for sweet compounds grab their respective molecules, and send the message through a series of coupled reactions to TRPM5, the second messenger, which in turn enables the cells to send the “sweet” message to the brain. TRPM5 turns on quickly, and then turns off quickly, so you sense a decrease in sweetness over time after the sip. Here are the results for the Pacherenc:

This figure was extracted from Figure 3 of the article, and shows the results for there successive sips of the Pacherenc wine. The thickness of the bars is proportional to the intensity of the sensation, and the length refers to the duration. "The x-axis of each graph represents standardized time between 0 and 1. Different letters on liking scores represent significant differences among sips for each wine according to LSD test. "

By contrast, astringency activates TRPV1, the hot receptor, which is activated by alcohol as well. TRPV1 is a “slow-on slow-off” receptor, so the effect builds. Think of your first bite of a food liberally sprinkled with hot peppers. You may say, “Oh it isn’t that hot!” only to experience a burst of pain milliseconds later. And as you keep eating the food, the effect gets stronger and stronger, and lingers long after you have stopped eating. This is what happens with astringency as well—by the third sip, the astringency is there all the time, and pretty much dominates the picture, as you can see in the diagram below.

This figure was extracted from Figure 3 of the article, and shows the results for three successive sips of the Madiran wine. Note the significant decrease in liking, the slower onset of astringency with the first sip, its quicker onset by the second sip, and its greater overall intensity with the third sip.

It’s worth noting that the alcohol perception for the Madiran wine was slight to non-existent, despite the wine's high alcohol content. In the presence of high tannins, astringency is sensed in preference to the alcohol burn, because astringency involves coupled signals with bitter receptors; the result is that our brains tend to choose astringency as the overall sensation. In addition, all the other possible flavors are virtually drowned out by astringency, and red fruits only have a chance to be perceived when the person actively switches from sensing astringency to sensing the fruit flavors.

Wine Wizard and Friend of Pairteas Tim Hanni MW (= Master of Wine) has been trying to promote the notion that many sophisticated consumers actually prefer the sweeter wines, and that this preference is especially pronounced for people whose palates are more sensitive—in other words whose palates may be more affected by strong sensations such as astringency.** 

Here is a group of French people who agree with him!

* Mara V. Galmarini, Anne-Laure Loiseau, Michel Visalli, and Pascal Schlich. Use of Multi-Intake Temporal Dominance of Sensations (TDS) to Evaluate the Influence of Cheese on Wine Perception. Journal of Food Science Vol. 81, Nr. 10, 2016. doi: 10.1111/1750-3841.13500. 

** http://www.winesandvines.com/template.cfm?section=columns_article&content=84604&columns_id=24&ctitle=Big%2C%20Dry%20Reds%3A%20Just%20a%20Fad%3F