Grape Seed
Also known as: Grape Pip, Grape Seeds, Grape Pips
The small, hard seed, or pip, inside the grape berry. Grape seeds are rich in tannins and related polyphenols, especially procyanidins. In drinks they contribute a dry, gripping, slightly bitter quality. They reach beverages mainly through winemaking, as part of the pomace distilled into spirits, and as a concentrated extract.
Usage in beverages
Grape seeds are a source of tannin during red and orange wine maceration. They are part of the pomace fermented and distilled for pomace brandies. Seed-derived tannin is sometimes added to wines to adjust structure. Grape seed extract appears as an astringent, polyphenol-rich ingredient in supplements and some functional or non-alcoholic drinks.
In depth
Ancient Origins in the Winemaking Crush
Grape seeds entered beverage history with wine itself. When early winemakers in the South Caucasus crushed grapes, the pips went into the vessel with skins, pulp and juice. Archaeologists date the earliest wine traces to around 6000 BCE near Tbilisi, and the oldest known winery, at Areni in Armenia, to about 4100 BCE. In these early ferments the seeds were simply part of the fruit. They quietly released tannin into the drink. Wine and its methods then spread around the Mediterranean through Phoenician and Greek trade, and later Roman production. So the seed's contribution to wine traveled wherever vines were planted.[1]
Tannin and Structure in Red and Skin-Contact Wines
In wine, the seed's main role is structural. Red grape juice is nearly colorless. Much of a red wine's color, and a good share of its tannic backbone, comes from phenolic compounds drawn out of the skins, seeds and stem fragments while the grapes soak in the fermenting juice. Winemakers manage this extraction with care. Seed tannins can turn coarse and bitter if the pips are crushed or underripe, so gentle pressing and attention to seed ripeness at harvest are long-standing concerns. Orange, or amber, wines apply the same principle to white grapes. Long skin and seed contact gives them a deliberately astringent texture. White wines usually limit skin contact to a matter of hours, because longer exposure brings bitterness.[1]
Medieval Italy and the Birth of Grappa
After pressing, winemakers were left with pomace, a cake of skins, pulp, stems and seeds. Distillation offered a way to avoid wasting it. Distilling knowledge reached Italy during the Middle Ages, likely from the Levant and Persia. Around the 14th century, water-cooled stills made it practical to distill pomace in quantity, and grappa emerged in northern Italy. Because grappa is fermented and distilled on the solids, the seeds and stems are co-fermented with the residual sugars. Their woody material yields small amounts of methanol, which distillers must carefully separate out. Around 1600, Jesuits in Italy, Spain and Germany helped codify distilling methods that were used for centuries afterward. Grappa is now a protected name in the European Union. It must be made in Italy from pomace, without added water.[2]
Greece and the Monastic Tsipouro Tradition
In northern Greece, a parallel tradition of pomace distillation grew up. Tradition credits Orthodox monks on Mount Athos with first producing tsipouro in the 14th century. Historically, wine was drawn off first, and only the remaining solids, seeds included, were distilled to make the most of the harvest. Tsipouro is usually double-distilled. Producers keep only the middle fraction, or heart, discarding the head and tail. An anise-flavored version appeared in the 20th century. Crete's tsikoudia is a single-distilled cousin. Both are drunk socially with small meze plates. Depending on season and hour, they may stand in for coffee or wine. Tsipouro received protected designation status from the European Union in 2006.[3]
Pomace Spirits Across Europe and the Caucasus
Nearly every wine-growing culture developed its own way of distilling the seed-laden residue of the press. France makes regional marcs, from Burgundy and Champagne to Provence and Alsace. Spain has orujo, Portugal bagaceira, and Germany Tresterbrand. Further east there are Hungarian törkölypálinka, Cypriot zivania, Bulgarian and Balkan pomace rakias, and Georgian chacha, made in the same Caucasus region where winemaking began. Pomace is classed by how much it has fermented. Fully fermented red-wine pomace is soft, dry and already alcoholic, which suits it well to distillation. Unfermented pomace from white winemaking must be fermented before it goes into the still. Most of these spirits are bottled clear and unaged, keeping the raw character of the pomace.[4]
Pomace Spirits in Coffee Culture and Abroad
Pomace spirits have become woven into everyday drinking rituals, often in very small measures. In Italy, grappa is a classic digestivo after a heavy meal. It is also splashed into espresso to make caffè corretto, or sipped alongside it. In the Veneto custom called resentin, a few drops are swirled through the sugary dregs of an espresso cup and drunk in one sip. Italian emigrants carried grappa to Uruguay and Argentina. Uruguay developed grappamiel, a honey-sweetened version, which is especially popular in winter. Over time, many traditionally clear grappas have also been aged in wooden casks, which gives them amber tones.[2]
Modern Extracts and Non-Alcoholic Uses
In the industrial era, grape seeds have been separated from pomace and processed in their own right. Pressed for oil, they yield a light-tasting cooking oil that holds very little of the seed's polyphenols. Most of those polyphenols are instead concentrated in grape seed extract, which is rich in procyanidins and produces a pronounced astringent sensation in the mouth. The extract is sold mainly as a dietary supplement. It is also used as an ingredient in some functional and wellness beverages. In winemaking, seed-derived tannin can be added to adjust a wine's structure. Producers of non-alcoholic and low-alcohol grape drinks can use the same astringent grip to restore the body that is lost with the alcohol. Research on health effects remains limited and inconclusive. Regulators have specifically warned against marketing the extract as a cancer cure.[5]