What’s Inside Red Wine
Patrick Di Justo
Photo: Kenji Aoki
Most cultures see something magical, even holy, about the way this toxin confuses our brain into thinking we are gods. It’s formed by microorganisms that eat sugar (C6H12O6) and excrete the waste as CH3CH2OH.
Some insist that this syrupy sugar alcohol, a byproduct of ethanol fermentation, is as important to a wine’s mouthfeel (texture) as ethanol itself. But while connoisseurs may credit it for determining “body” and “silkiness,” chemists haven’t found a clear connection.
These astringent molecules found in grapes (and in the oak barrels used in winemaking) do a real number on your tongue. Their multiple phenol groups bind to salivary proteins, making your mouth feel drier than it should when it’s full of liquid. This odd effect is what oenophiles call a “gripping” mouthfeel.
- Malvidin 3-Glucoside
One of a family of natural pigments called anthocyanins. Also known as oenin, it puts the red in red wine.
- Catechin and Caffeic Acid
Catechin is a phenol antioxidant found in grape seeds. Caffeic acid is another phenolic compound found in grapes. Together they have the serendipitous benefit of preventing DNA damage from ionizing radiation and reactive oxygen molecules. Send a magnum to your local nuclear plant workers.
This chemical gives Cabernet Sauvignon its herbaceous green pepper aroma, detectable at as little as six parts per trillion. Connoisseurs note: If the smell is overpowering, it could mean the grapes were not allowed sufficient time to ripen—IBMP breaks down as grapes mature. Or leaves may have gotten into the ferment (the green parts of the vine are chock-full of IBMP).
Wine-and-cheese parties give you a migraine? It might not be the pretentious banter. You could be overdosing on this amino acid, which is found in both foods. It constricts cerebral blood vessels, and when they reopen, you get a throbbing headache. So skip the cheese, but be sure to nosh on something; you’ll absorb less tyramine if you have food in your stomach.
- Malic and Lactic Acids
Malic acid occurs naturally in grapes. But too much of it gives vino a harsh “green” taste that clashes with other flavors. Most vintners let the wine age a bit so bacteria can turn malic acid into the “softer,” “rounder” lactic acid.
The antioxidant that’s been touted for the past decade as a miracle cure-all: It fights cancer! Tames diabetes! Keeps winos alive forever! But in some mice, resveratrol inhibits the absorption of dietary iron, causing anemia.