Pomace (or in French marc) is the remaining solid material of grapes after pressing for juice – containing the skins, pulp, seeds and stems of the fruit. The word Pomace is derived from the Latin ‘pomum’ (meaning fruit or fruit tree).
Pomace in winemaking differs, depending upon whether white wine or red wine is being produced. In red wine production, pomace is produced after a period of time the juice is poured off, leaving behind dark blackish-red debris consisting of grape skins and stems. The resulting pomace is more alcoholic and tannic than pomace produced from white wine production.
In white wine production, grapes are quickly pressed after crushing to avoid skin contact with pomace as a by product of the pressing. The resulting debris is a pale, greenish-brown colour and contains more residual sugars than it contains tannins and alcohol. It also has nitrogen, amino acids and other goodies that didn’t make it into the fermentation tank.
In Verona, Italy winemakers re-use skins by placing the pressings from red wine, into another fermentation tank to get more mileage from the grapes. By crushing fresh red must over already-pressed and fermented red pomace, it’s possible to extract even more of the colours, tannins and – if the grapes were at all raisined and not completely fermented sugars. The most famous and delicious examples of this technique is the Italian ‘Ripasso’ wines where the sweet, raisined pomace from Amarone della Valpolicella is added to other red ferments of lighter style red wine. These wines, having been ‘re-passed’ over the sweet, flavourful Amarone skins, are richer and have more depth than they would have had on their own.
Provided by: Wine Guy