Wal also writes about Grappa ...
    Rum is made from the waste material (molasses) from sugar processing. Grappa is made from the waste material (pomace) from wine making. It was the drink of the frugal rural folk as there is still sufficient alcohol at about 12% present in the pomace. A more literary name would be "acquavite di vinaccia". Vinaccia is Italian for pomace. For similar reasons in Greece they make tsipouro/raki/ouzo out of stemfila which is Greek for pomace.

    For the Greek version and using a single distillation, herbs (anise seeds etc.) are placed in the bottom of the pot to prevent the pomace from burning. Possibly 500g of aniseed/100kg pomace is used (this produces about 5l of spirit). For a second distillation product, steeping 100g of aniseed/litre of spirit and redistilling seems right (about the equiv. of 50 drops of aniseed oil/litre of spirit). In France grape residue is called marc and its used to make "eau-de-vie de marc".

    Because grape residue contains seeds and stems, elementary distillation produces a rough product which was avoided by more discriminating drinkers. The seeds also produce quite a bit of methanol. Pomace after a first pressing contains much of the flavor of the particular grape type and thus the final product resembles brandy or fruit-based liquor. Lighter pressing of the grape must, better distillation techniques and packaging have made grappa into a sophisticated liquor.

    The vinaccia should be distilled within 48 hours of pressing otherwise the aromatics disappear, and oxidation and acetification starts. On average 100kg of grape pomace yields from 4 - 8 litres of grappa at 70%abv. In making white wine, the grape is pressed first to extract the juice (100kg grapes produce about 55litres of juice), so the pomace from white grapes must be fermented separately to produce grappa. Water (or steam) is added to the red grape pomace resulting in a slurry called flemma which is then distilled. Water is added to white grape pomace which is first fermented and then distilled.

    Traditional method:
    Load 100kg of pomace with an equal weight of water (100litres) in a pot still and distill. Triple distillation is common commercially. Normally it is diluted to 45%abv.

    In Italy grappa is normally an after dinner drink (digestive), or on a cold day you can have it with your morning coffee! Last vintage I decided to try a modern method using the red pomace to provide nutrients and flavor. The yeast was already present.

    Grape's Components:
    • Stalk 3-5%
    • Skin 6-10%
    • Pulp (water, sugars, minerals) 82-90%. The actual water content of grapes is approx. 65-75%.
    • Seeds 2-4%
    The grape pomace (vinaccia in Italian) contains about 10% sugar or 5% alcohol if fermentation has occured. Traditionally equal quantity of water was added and redistilled in a pot still. A modern grappa recipe could be based on making a 'false wine', as sugar is affordable these days, and then distilling as for brandy.

    Modern method:
    50 kg of pomace with 100litres of water (2 kg / 4 L)
    25 kg of white sugar ( 1 kg / 4L)
    Referment for a week, press out and distill the clean wash. I used a reflux tower with a jacket reflux and vapor condenser and which produces 75%abv which is a great brandy base. I kept 5 litres of the reconstituded wine under an air lock for 6 months and it made a reasonable light wine. This is based on the fact that to "reconstitute" the pomace to make a pseudo wine, we need 2kg pomace, 4l water and 1kg of sugar. These proportions are approx. equivalent to 7kg of fresh grapes which give about 4l of wine.
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