What do you mean "press grapes?" Didn't you, like, already do that last week? Like medical jargon or legal-ese, enology boasts its own vocabulary. While "crushing" grapes is basically synonymous with smooshing, stomping, smashing, squashing, pounding, or flattening, it is not the same as "pressing." "Crush" is a technical term that encompasses any means of breaking the skin of intact berries to release the juice within. This is the crucial step that colors white grape juice red; skin/juice contact gives red wine its gorgeous purple-ruby hue. For red wines only, "press," by contrast, happens after primary fermentation is complete. It is the technical term that describes extracting the liquid (i.e. wine) away from the gooey, wet grape-pulp-skin amalgam, akin to wringing a wet towel dry, but more gingerly.
In the fermentation vessel, the nascent wine mingles with the solid residua, which includes grape pulp, skin, seeds, dead yeast, and an odd insect or two (just kidding). Next a hose or pump is used to drain the wine away from the solid muck. The wine that simply flows away from the solids, like a cascading, maroon river of edible hedonism, is called the "free-run." (With that, I kill the abysmal similes and pronounce them dead). Free-run is generally considered the highest quality wine, since it is lowest in tannin. After that, the solid remains are compressed with progressively greater force until they are dry. The wine borne from the consecutive pressings can kept separate or combined with the free-run, as dictated by the winemaker's tastes, since flavors in press fraction wine may add depth, backbone, and complexity.
Each consecutive press fraction has progressively higher tannin, since vigorous pressing can shear or even pulverize the grape seeds, releasing bitter and astringent components into the wine. Sometimes the highest press fractions are tossed in the garbage or sold to Franzia or other fancy box-wine hawkers. In the super, olden days, like when my mom was a kid, a wine press consisted of a heavy piston grinding the piss out of grape solids in a wooden basket, so escalating tannin was problematic. But with the advancement of wine technology, the newest and gentlest presses are bladder presses, which is what we will be using on our wines. In essence, a bladder press is similar to inflating and deflating a balloon inside of a round container, with gently increasing pressure. Because compression is so subtle and controlled, seed breakage is negligible, and all press fractions are of high enough quality to be reunited with the free run.
Every winery has a personalized press program, which dictates what type of press is selected, how much pressure is used, the number of presses, and the fate of each successive press fraction. In his book North American Pinot Noir, John Haeger discloses the press program secrets of America's finest pinot producers. At Calera, "The pomace is bladder-pressed when the must is dry; the press fraction is immediately reassembled with the free-run juice" (p228). In contrast, at Flowers Vineyard and Winery, "Flower's basket press works very gently, so the first and second press fractions can usually be recombined with the free run juice; subsequent fractions are evaluated lot by lot" (p285). Then at Williams Selyem, "The press juice, instead of being barreled separately, is used to top up each free-run barrel" (p393). Evidently, the options and choices are innumerable, and these details constitute the art of winemaking.
At Bruliam, we're just excited to taste our first wine ever! High on endorphins and adrenaline, I suspect we'll pronounce both the free-run and each successive press fraction "delicious!," "stupendous!," and "the best wine ever!" Next week, we can Monday morning quarterback our decisions and reassemble our press program for your entertainment.