This Saturday will be the Appointed Time to "stabilize" the Pinot I've been fermenting. I'll be stirring a quantity of sulfites (potassium metabisulfite, if I'm not mistaken) into the infant wine to "stabilize" or stop the fermentation by (mostly) killing the yeast. In addition, I'll be adding a gelatin mixture and some dry clay called bentonite to "clarify" the wine, thus causing undesirable compounds (that would make it cloudy and/or taste odd) to precipitate out onto the yeast detritus on the bottom of the carboy.
One of the things that I've been fascinated with about the winemaking process is that it's a much more clinical and, well, synthetic-feeling process than brewing beer was. Certainly, brewing incorporates all manner of complicated measures like temperature regulation to maximize the action of certain enzymes in the mash, and siphoning and sparging methods to get the sugar-extraction job done, but that always felt somehow biological and mystical to me, more than chemical and logical, which is the impression winemaking gives so far. The difference is mostly semantics, I know, but making wine has been much more of a predictable, dump-it-into-a-container-and-add-stuff process than beer's bubble-bubble-toil-and-trouble ever was.
I know that the yeast is transforming the grape juice just as much as it did the barley brew, but winemaking seems a more clinical and exact thing than brewing. Not that I'm complaining, of course: beermaking involves making an elaborately-seasoned malt sugar solution called wort (which happens to be one of the most biologically "available" media you can make in the home) and then getting only the microorganisms you choose to flourish, and no others.
The central difference where wine is concerned is that wine "must" (prepared grape juice, pre-yeast-introduction) is inherently fairly acidic, and therefore inhospitable to many of the nasty-tasting microbes that love to mix things up in beer. Not that wine is idiot-proof: there are many nasties that can compete with the several flavors of Saccharomyces that one introduces to get fermenting done, but far fewer than in beer, and by judicious use of sulfites in wine, one can make a must that is very well suited only to the yeast you like.
Anyway, it's reassuring to know that the process is so well understood (given the several millennia of crushing experience the human species has amassed): winemaking books read more like formulae than do beer brewing's recipes. Might this be due to wine traditionally being more of a luxury product, and thus more likely to receive research attention? Possibly; I'll look into it.