That’s not an oak tree in your mouth, it’s a seed

I’m sitting in a rather warm room at Washington State University’s ag extension research center in Prosser trying very, very hard not to nod off as Dr. James Harbertson shuffles through a PowerPoint presentation on phenolics. My breathing slows, my head empties, and slowly I enter that strange half-asleep, half-awake stage familiar to frequent fliers where you subconsciously hear someone say “What can I get you to drink?” while dreaming about being lost in a house, naked, inhabited by everyone you ever met in high school and college.

Except instead of hearing “What can I get you to drink?” I hear, “Oak barrel tannins are sort of a myth.”

Like a superhero rising from the ashes before being thrown off the roof of a skyscraper by Lex Luthor, I struggle mightily to rise from my semi-comatose state just in time to keep the drool from dripping onto my shirt. Forcing open my eyes, I mumble, “Wait…what? Oak barrel tannins are a myth?”

Exactly, says Dr. Harbertson.

Holy kryptonite!

Photo by David Lansing.

Photo by David Lansing.

See, we have come to the WSU ag station to sit around on a hot afternoon sipping/spitting barrel samples of various red wines to learn what role tannin plays in wine structure and how to control it. Now, I could give you the two hour PowerPoint presentation Dr. Harbertson has just given or I could give you the nickel version, your choice.

Okay. The nickel version: Tannins are what give red wines weight and structure. They’re what allows a good red wine, like Bordeaux, to sit in a bottle for 10 or 15 years and only get better while white wines (which have almost no tannin) age about as well as Keith Richards. So tannin is important. Too little and the wine falls apart. Too much and your mouth puckers and you want to spit.

So if you’re a winemaker, you need to know how much tannin is in the wine and where the tannin is coming from. Now I always knew that much of a wine’s tannin came from the skins and seeds, but I also thought, like a lot of people, that red wines also picked up tannin from the barrels they were aged in. Thus, a wine aged in oak barrels for three years would have significantly more tannin than wine aged in barrels for nine months, yes?


“From a scientific viewpoint,” says the boyish Dr. Harbertson, “you get almost no tannin from oak barrels.”

I mean like nothing.

Wow. What you do get are aroma components. The nose is aware of the oak. But the mouth isn’t. The mouth is aware of the grape seed.

So the next time you taste an overly-astringent cabernet sauvignon and your friend wrinkles her nose and proclaims, “Spent too much time in the barrel,” smile and say, “Oak has nothing to do with it, Lois. It’s actually too much pumace during fermentation.”

And if she doesn’t believe you, tell her to contact Dr. Harbertson. Or Clark Kent.

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1 comment

  1. Fred Harwood’s avatar

    From Wikipedia:

    The English word for tanning is from medieval Latin tann?re, deriv. of tannum (oak bark), related to Old High German tanna meaning oak or fir (related to modern Tannenbaum). This refers to use of the bark of oaks (the original source of tannin) in some kinds of hide preservation.

    The association of oak and tanning (from the bark and not the wood) may be some part of the reason common sense suggests that oak barrels and tannins have something in common. As an amateur cabinet maker, I can attest to pungent and irritating oak dust, a smell and excessive flavor that I have used to signal what wines I avoid. Also, the perhaps momentary popularity of grape seed extracts as beneficial for almost every thing from decreasing heart problems to pregnancy stretch marks wars against jailing grape seeds. However, I concur. Grape seeds, chewed in the mouth, appall.
    Which suggests that wine should be consumed, not aged. Too many destructors at work, and we are but mortal.

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