How the Romans Made a Sweet Wine from Raisins (Passum Vitis)
Passum Vitis is the modern name often given to a Roman sweet wine made from very ripe or sun-dried grapes. It offers a useful answer to a common assumption: ancient people did not need cane sugar to create a rich, raisiny drink. Roman growers dried fruit until much of its water had gone, pressed the concentrated mash and fermented the juice. Passum could be poured in small servings or mixed with water, depending on its strength and the occasion.
Reconstructing it requires care because passum was not one fixed recipe. Cato, Columella and Pliny describe related processes that differ in detail, and “Passum Vitis” is a modern scholarly label rather than a brand Roman drinkers would have read on an amphora. Textual evidence is strongest when combined with residues from pottery and traces of the wine trade. Archeoricette’s research project brings those strands together, showing why historical raisin wine should be treated as a concentrated fermentation rather than a modern sweet wine with raisins added.
Evidence Behind the Roman Recipe
Cato’s De agri cultura gives one of the clearest surviving accounts of making passum from grapes dried in the sun. Columella’s De re rustica supplies wider information about grape selection, pressing and storage, while Pliny’s Natural History records sweet wines and their qualities. The word passum is often linked to the Latin idea of something spread out, apt for grapes laid across roofs, mats or racks to dry. These sources point to a practical estate-level process that depended on ripe fruit, dry weather and careful timing.
Archaeology adds colour without pretending to provide a complete recipe. Analyses of amphora residues can reveal compounds associated with ageing or sweetening, and finds of grape pips, stems and wine-making debris show how fruit was handled. Chemical traces rarely prove that a vessel held dried-grape wine rather than another concentrated must. Roman names and boundaries were also fluid. Passum was therefore a family of products, and the safest reconstruction explains both the shared method and the differences among named grades.
Drying Fruit for a Sweeter Must
The first concentration came before fermentation. Growers selected large bunches of very ripe grapes, often from sun-exposed vines, then spread the fruit in a single layer. Sun, shade and airflow did most of the work; the fruit was turned so that it dried evenly instead of moulding. As the skins collapsed and the berries became leathery, water evaporated and sugars and acids became more concentrated. The dried fruit was then destemmed and often cleared of some seeds before pressing.
Australian shops offer a revealing range of dried fruit. A small Thompson Seedless becomes a sultana, while Zante Corinth grapes become currants; both can make an expressive modern experiment. Many supermarket dried grapes are treated with sulphur dioxide to maintain colour and shelf life, a modern intervention Romans did not use. At Melbourne’s Queen Victoria Market, ask a dried-fruit or baking vendor about unsulphured stock, then check the ingredient panel again at home. Adelaide’s Central Market and Sydney’s The Rocks Markets can likewise anchor a tasting walk through regional foods before the blending begins.
Pressing Must and Fermenting the Concentrate
Roman must was grape juice before fermentation. After the dried berries were crushed and pressed, their juice could ferment on its own; some written recipes also mixed pressed dried fruit with fresh must, giving the ferment more liquid and balancing its force. The sugar in the grapes supplied the alcohol, not distillation. This matters historically: Roman passum was not spirit poured into ordinary wine. Fermentation took place in vessels such as estate jars, while finished wine could be transferred into transport amphorae fitted with stoppers and seals.
The contrast with grain fermentation is instructive. For a companion experiment based on fermented barley, the Ancient Mesopotamian beer guide follows another ancient route to alcohol and shows how researchers test technique, equipment and microbial change. Grape and beer workshops also face a shared practical problem: successful fermentation requires hygiene, a suitable temperature and enough viable yeast without letting unwanted mould dominate.
| Method | Starting material | Main treatment | Likely character |
|---|---|---|---|
| Everyday Roman wine | Freshly pressed must | Fermentation in jars or storage vessels | Often dry, with grape and vintage strongly influencing balance |
| Passum Vitis | Very ripe grapes, often dried and sometimes combined with fresh must | Pressing and fermentation after concentration | Dark, rich and sweet, with alcohol developed in situ |
| Sapa or defrutum | Fresh grape must | Boiled to reduce the water content | Thick concentrate used as an ingredient or sweetener |
| Modern fortified sweet wine | Fresh must and sometimes concentrated grape juice | Fermentation followed by spirit and sometimes sugar | Higher alcohol and greater stability, with a different balance |
These related products should not be treated as interchangeable. Passum was more than reduced must: fermentation supplied its alcohol and living aromas. A modern fortified wine is also an unsuitable shortcut, since added spirit changes both strength and preservation. An experimental batch therefore gives dried fruit and grape juice precedence over brandy, syrups or commercial dessert wine.
Controlling Sweetness, Strength and Age
Passum’s character depended on how far fermentation proceeded. More sugar in the must allowed alcohol to rise while some sweetness remained; acidity and oxygen exposure affected whether the drink tasted fresh, vinous or oxidised. Roman writers describe methods that could arrest a fermentation before all its sugar disappeared, while sweet must could also be reserved for blending later. Sealed or partly sealed storage helped limit exposure, although no single vessel practice explains every regional example. Pliny’s praise for aged wines should not be read as a promise that every passum improved indefinitely.
Modern Australian winemaking makes these variables easier to observe. Small producers and hobbyists around the Barossa Valley, Hunter Valley and Margaret River routinely track temperature, sugar and acidity, while a Sydney or Melbourne home cellar may be warmer than ideal. A cool ferment around 18–22°C generally gives a cleaner result than a kitchen bench in summer. Hydrometers, airlocks and sanitised glass now provide control that Roman growers lacked, yet leaving the final balance to the palate keeps the experiment faithful to the evidence rather than to a standardised modern recipe.
Reconstructing the Flavour and Serving
No sensory panel has tasted Roman passum, so its flavour must be reconstructed from the ingredients and process. A sound result should be dark amber to brown, full-bodied and clearly sweet, with dried grape, fig or raisin notes. Fermentation can add bread-like yeast aromas and restrained fruit acidity. Words such as honeyed or fig-like are modern descriptions, useful for judging an experiment but not direct quotations from a Roman cook. Dark fruit and visible sediment may also affect texture, while ageing softens sharp fruit flavours.
Serving depends on whether the aim is archaeological accuracy or a modern Australian interpretation. A historical-style batch can be tasted alone, because concentrated Roman wine did not always require dilution, or compared with water as a check on intensity. A contemporary cheese board offers another lens: try it with aged cheddar, blue cheese or pecorino, then with roast nuts and fresh fruit. That combination follows present Australian custom rather than a securely documented Roman menu. For fruit-led, plant-based accompaniments, Danielle’s vegan recipes provide a modern point of reference; check any sweetening or fining ingredients when planning the serving.
Make a Small Batch of Passum Vitis
Begin with a controlled 750-millilitre trial. Obtain fresh must by pressing ripe, untreated grapes, reserve some of it, and combine it with 250 grams of unsulphured dark raisins or sultanas that have been lightly crushed. This follows the Roman principle of combining dried fruit with grape juice. If fresh must is unavailable, use unsweetened, unfiltered grape juice without preservatives and add a suitable wine yeast, but record the substitution because the result will be less exact. Do not add cane sugar if the purpose is to test the ancient process.
Place the mixture in a sanitised jar with an airlock and ferment it at about 18–22°C, away from Australian summer heat. Taste after two weeks and continue until the balance suits you, watching for the point at which residual fruit sweetness remains. Because some batches stall before all their sugar ferments, use clean equipment and refrigerate a stopped batch; never assume that residual sweetness makes a low-alcohol drink safe. Add raisins directly to the must rather than dissolving them in tap water, which would produce a modern raisin drink rather than a passum-style fermentation.
Make the batch this weekend, bottle it only once fermentation has stopped and the sediment has settled, and serve it beside an Australian cheese board to judge sweetness, acidity and aroma. Keep the tasting notes beside the recipe and share the result with a fellow experimenter.
