Last week we talked about how the grapes are sorted once they arrive on the crush pad. So what comes next? The sorted grapes are ready to be fermented at this point. We use two types of containers to ferment the fruit in, large stainless steel tanks and smaller plastic bins. Red wine goes through primary fermentation with the grape skins, which is where the vine gets its color. In fact, you can actually make a white wine from a red grape if the juice is immediately separated from the skins. Much of the tannin that gives red wine its structure is found in the skins so it is very important that the fermenting juice, or must, is in contact with the skins.
The skins float though, so they constantly rise to the surface forming a thick layer we call the cap. In order for the skins to fully transfer the flavor to the must, they must be re-submerged periodically, usually several times a day for the full duration of fermentation. This process is called a punchdown. You may have seen pictures of people on top of vats of grapes, holding themselves up while using their feet to push the skins down. Well we don't use our feet anymore but I guess the name stuck because the tool you use to punchdown the cap is called a foot. They come in many sizes and shapes but are usually just a rod with a flat surface with holes in it at one end. We've got several varieties of them here at Deerfield and I think everyone has their favorite one.
During crush we often have as many as 40 lots of wine fermenting at one time. Our protocol calls for each of these lots being punched down twice a day. So usually while the majority of the crew sorts fruit, one lone cellar rat goes from bin to bin punching down the skins. By the time you get done with the last one it is usually time to go back to the first one and start again. It's quite a work out. Sometimes it's as easy as pie but occasionally the cap is compacted and more than a foot thick. Perched precariously on the thin lip of the bin, wearing slippery galoshes, you throw your full weight onto the foot. Suddenly the cap gives way and you feel all resistance disappear. Falling into the delicate fermenting fruit is not an option so desperately you lean backward to regain your balance. Phew! Repeat another 40 times. The cap of the large stainless steel tanks is often too thick to punch down by hand so we use an alternate method which we call a pump-over that I'll go over next week.