Thursday, January 17 2008

The Grapes of Math

Bubble, bubble toil and trouble . . .

Whitman said, 'Do I contradict myself? Very well then I contradict myself, I am large, I contain multitudes.' I have to admit, I'm a lot larger than Whitman, although I'm on the other side of temperance from him and look less like Gandalf. No, my contradiction lies in my devotion to traditional thinking about wine and the expression of grapes while working in the winemaking industry at a time of unparalleled scientific research and technological development. I'm particularly bemused by the level of manipulation that a lot of wines get--things like alcohol reduction, micro-oxygenation, polyphenol fractionation, etc.

Sure, Winexpert balances and blends wines to achieve goals for flavour, aroma, varietal expression, colour and a host of other factors. But that's traditional winemaking. The techniques I'm thinking of are offshoots of new technology and new research into the physics of wine, not just the empirical chemistry.

I've mentioned alcohol reduction a few times. It's the process whereby wines partially distilled and de-alcoholised after fermentation. This allows a winery to hang grapes until they're jammy little raisins, and then avoid the penalty (hot, harsh wines overwhelmed by alcohol). But it's micro-ox that's a fascinating case.

Micro-ox is the process of introducing small, controlled amounts of oxygen into fermenting wine. The goal of this is to change the tannin structure of a young wine, reducing the throat-catching young tannins and giving the wine a soft, smooth mouthfeel. It also influences colour stability, promotes fruit and oak character, reduces vegetal notes, and helps remove disulphides (that rotten egg smell sometimes seen as a result of low-oxygen fermentation).

Unfortunately, micro-ox wines usually wind up with a bland sameness of flavour. By bashing the tannins down with a hammer, tuning up the fruit and oak (and usually over-oaking the wine into a plywood bomb) the winemaker takes perfectly well-adjusted grapes and makes the new international style of red wine, usually with some dopey cartoon animal on the label and a huge marketing budget. To be fair, some of this is not due to micro-ox alone: fruit selection, hang time and the addition of exogenous tannins and mannoproteins all have their role.

Funny enough though, micro-ox used to be the norm in winemaking, but under very different circumstances. Up to about 40 years ago tanks in many wineries were still made of wood, or barrels were used for fermentation and ageing. Hoses and pumps leaked, punching down the cap introduced air, and it was a field day for the introduction of oxygen into wine. Like as not this introduced too much oxygen, leading to VA (a hint of vinegar in the wine) or other spoilage issues.

Nowadays it's all stainless steel, hermetic seals, fabulously tight pumps and hoses and no oxygen introduction at all--unless it's done by order of the winemaker or consultant. Even barrels are used less and less–or not at all, if the wine is cheaper than $15 a bottle. Good barrels are simply too expensive, so chips or other oak products are introduced to the stainless tanks instead, robbing the wine of another uncontrolled splash of oxygen.

Winexpert kits do get a little oxygen introduced during their processing, but it's done the old-school way, through racking and stirring during the fining/stabilising process. I'm not contending that this is better, or even necessarily desirable. But micro-ox is one of those things that seems a little like Mickey Mouse's brooms in Fantasia: used like a clockwork procedure on every wine in sight it makes bland samey-same wines, like the old saw about if your only tool is a hammer, pretty soon every problem starts to look like a nail . . .

Anyone interested in a little of the science behind micro-ox, and a bit of the answer back to it, should check out The Grapes of Math (what, you thought I was original?) at PBS. While they're not big on stirring the controversy, it's pretty balanced and quite informative.

Speaking of oxygen, it's time to come up for some air!

Posted by Tim AT 10:35PM

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