I really enjoyed my month long anesthesia vacation, I mean “rotation,” during my surgical internship. It was a nice break from general surgery. Nobody threw sharp instruments at your head when you misidentified a blood vessel. The hours were better. You could flip through a trashy magazine, hidden inside the cover of the New England Journal, while the patient was asleep. Reclining in that cushy stool, you could snicker at the poor surgical intern holding her bladder and the retractor and rejoice, “Thank God I’m not scrubbed into that 12 hour vascular mess.” But karma is a bitch; anesthesia is all about the spit. And the phlegm. And the disgusting saliva you had to suction away with a maddening, nauseating slurp. Saliva is not my thing. Unfortunately the study of wine necessitates spit, gross but necessary. A few weeks ago, when I attended the Pinot Days festival in San Francisco, I spent 4 hours trolling from booth to booth with my red plastic spit cup. I never really dwelled on the content of that icky plastic spittoon until recently. Nestled within last week’s reading assignment, my UC Davis syllabus contained the following gem. The author noted that the murky mixture of spittle and discarded wine will “cause “clots” in expectorated wine samples.” To imagine a flocculating coagulation of spit + wine protein floating like an island in a frothy merlot sea will kill an appetite. Even mine.
As it turns out, there is a considerable body of academic research concerning wine and saliva. Who knew? One researcher went so far as to measure how much spit your mouth produces after sipping, swirling, and spitting out a mouthful of wine. In case you were curious, saliva production revs up after 10 seconds and peaks at 20 seconds. After that your mouth kind of peters out and dries up without the “additional stimulation” of water or a saltine (Lesschaeve and Noble). Better yet, researchers have identified a “new [spit] protein.” Investigators invited folks to drink wine and grape seed tannin solutions and then analyzed their spit eight minutes later. Spit study revealed a novel protein peak, presumably a conglomeration of icky saliva goo stuck to wine funk (ibid).
Most of this research derives not from pranksters and lovers of all things gory and gross but instead from folks studying the sensory analysis of wine. Much is rooted in the study of wine tannins. Tannins are of course the stuff of fuzzy purple teeth. Tannins are what make those big cabs and syrahs so mouth drying and “puckery.” Tannins are responsible for what the cabernet crusaders call “astringency.” I am talking about when your tongue gets rough and sand-papery, your cheeks are sucked dry, and your lips crack after swigging too large a gulp of $12 cabernet. Have you ever had the sensation that the more cab you drink, the more prickly your palate feels? You’re not crazy. Actually, research proves that unpleasant feeling is cumulative.
As you slosh back glass after glass, the tannins accumulate, and their effect is compounded like the vig you owe the bookie. Researchers can actually test this by asking judges to keep sipping vino at specified intervals while continually rating the intensity of the astringency. The fancy term is “carry over.” Please tell us, sirs, is your tongue (a) barely brambly, (b) chapped and coarse or (c) harsh and coarse-grained like a scouring pad? Does the NIH fund those scorecards? By the way, increasing the time intervals between sips to 30 seconds “considerably reduced” the sand paper effect of each subsequent sip (ibid).
There happens to be logical physiology to explain why your mouth feels like a pumice stone. Tannins, which are promiscuous chemical chains, like to hook up with any available proteins, whether intrinsic to the wine or not. Saliva is chock full of proteins, including proline-rich ones, which are particularly attractive to polyphenols (i.e. tannins). When you sip a tannin-heavy wine, the tannins stick to your salivary proteins and gum them up. You feel your salivary flow rate drop, and “oral lubrication” decreases. This is friction in your gums and postulated to be the mechanism of astringency. (By the way, this is also the premise of protein “fining.” You mix your immature wine with a protein solution to suck up the extra tannins before bottling).
The next time your host serves some young, outrageously tannic behemoth, your best bet is to pace at one swig/minute. At least you’ll overcome the tannic carryover until you’re able to dump the remaining drops in a nearby planter.
Lesschaeve, I., and A. C. Noble. 2005. Polyphenols: factors influencing their sensory properties and their effects on food and beverage preferences. Am J Clin Nutr 2005 81: 330S-335. http://www.ajcn.org/cgi/content/full/81/1/330S.