Cooking Syrups and Wines
from https://prospectbooks.co.uk/samples/CookingApicius.pdf

Grape must syrups

Must (from the Latin vinum mustum, "young wine") is freshly crushed fruit juice (usually grape juice) that contains the skins, seeds, and stems of the fruit. The solid portion of the must is called pomace and typically makes up 7–23% of the total weight of the must. Making must is the first step in winemaking.

Besides fermenting, another technique used in the preservation of wines was reduction by evaporation. The Romans even spoke of different types of reduction. There were four types of wine: sapa (reduced to one‑third, according to Pliny the Elder); defrutum, which according to Columella in his “Agricultura”, Vol. XII, involved boiling until reduced to half the original volume and allowing it to age for a period of one year; caroenum, a reduction to two‑thirds of original volume (according to Palldius); and, finally, the passum, a dessert wine of Phoenician origin made from raisins (according to Columella). 

The ancient Greek name for grape syrup is siraios (σιραίος), in the general category of hepsema, which translates to 'boiled'. The ancient Greeks used several variations of sweet grape juice, distinguished by the degree to which they were boiled down, or concetrated. There was the highly prized gleukos, which denoted either the fresh, free-flow must that was obtained from fully-ripe or overripe grapes before treading or the fermented product of this must; then there were several concentrated forms: hepsema (ἕψημα), which was grape juice concentrated by boiling until rather thick, and which was a cheap substitute for honey; hepsetos, which was less concetrated; and, finally, siraion, yet another concentrated grape must, but to what degree or thickness it is hard to determine.

One of the earliest mentions of grape syrup comes from the fifth-century BC Greek physician Hippocrates, who refers to hépsēma (ἕψημα), the Greek name for the condiment. The fifth-century BC Athenian playwright Aristophanes also makes a reference to it, as does Roman-era Greek physician Galen.

Grape syrup was known by different names in Ancient Roman cuisine depending on the boiling procedure. Defrutum, carenum, and sapa were reductions of must. They were made by boiling down grape juice or must in large kettles until it had been reduced to two-thirds of the original volume, carenum; half the original volume, defrutum; or one-third, sapa. The Greek name for this variant of grape syrup was siraion (Greek: "σίραιον").

There is some confusion as the amount of reduction for sapa and defrutum. As James Grout explains in its Encyclopedia Romana, authors informed different reductions, as follows: The elder Cato, Columella, and Pliny all describe how unfermented grape juice (mustum, must) was boiled to concentrate its natural sugars.

"A product of art, not of nature," the must was reduced to one half (defrutum) or even one third its volume (sapa) (Pliny, XIV.80), although the terms are not always consistent. Columella identifies defrutum as "must of the sweetest possible flavour" that has been boiled down to a third of its volume (XXI.1). Isidore of Seville, writing in the seventh century AD, says that it is sapa that has been reduced by a third but goes on to imagine that defrutum is so called because it has been cheated or defrauded (defrudare). (Etymologies, XX.3.15).

Varro (Roman, 116 BC - 27 BC) reverses Pliny's proportions altogether (quoted in Nonius Marcellus, De Conpendiosa Doctrina, XVIII.551M - Roman grammarian of the 4th or 5th century AD).

Defrutum

The main culinary use of defrutum was to help preserve and sweeten wine, but it was also added to fruit and meat dishes as a sweetening and souring agent and even given to food animals such as ducks and suckling pigs to improve the taste of their flesh. Defrutum was mixed with garum to make the popular condiment oenogarum. Quince and melon were preserved in defrutum and honey through the winter. Defrutum is mentioned in almost all Roman books dealing with cooking or household management. Pliny the Elder recommended that defrutum only be boiled at the time of the new moon, while Cato the Censor suggested that only the sweetest possible defrutum should be used.

Defrutum is a syrup made from grape juice. It has special flavouring and needs to be quite thick. It is defined as ‘fresh must boiled down to 1/3 of its volume’.  This reduction is not necessarily fixed as the sugar content of grape must can vary. What matters is the flavouring. This could be from either figs or quinces, added to the syrup while cooking. It is possible to purchase this variety of syrup in Italy and the UK today. It is known as ‘Vincotto with figs’.  The English translation on the label is ‘sweet vinegar condiment’ but this is not quite accurate. It is not a vinegar as it has not soured, although it has been aged 4 years.

Homemade recipe for Defrutum

After conserving your must in a sterilised swing-top bottle, leave it to age in a cool, dark place for several weeks, and, if you're patient enough, months. You'll find that your syrup undergoes a transformation, deepening in colour and mellowing in taste.

2kg ripe red or white wine grapes (4.4 pounds)

Wash and dry grapes. Remove carefully from stems and pass through a food mill in batches. Discard seeds and skins which will have accumulated on the top of your food mill's disc. Filter must through a fine-mesh sieve lined with cheesecloth. Pour filtered must into a heavy-bottomed stainless-steel saucepan and bring to boil.

Lower heat to a gentle boil and remove any foam which rises to the top with a slotted spoon. Cook from 1 to 3 hours (the time will depend on the sugar content of your grapes). As the must cooks, it will reduce in volume, thicken and start to emit a cooked scent.

Remove from heat when your must has reduced by at least three-quarters of its initial volume and has the consistency of a syrup. Cool syrup to room temperature. Strain it through a fine mesh sieve lined with damp cheesecloth. Using a funnel, pour syrup into a sterilised swing top glass bottle or bottles. Keeps in a cool, dark spot for a year.

(yields about 1.5 mL fresh grape must and about 350 mL of grape must syrup)

Caroenum

The identification of this particular liquor is difficult as it is barely mentioned in ancient texts. We know that it is a grape syrup, made by reducing grape juice/must, the best educated guess is that it is similar to Defrutum but thinner. According to Grainger and Dalby, it is reduced by 1/3 to 1/2.  They also believe that it was made from white grape juice, and that its purpose was to add 'bulk' to a meal, rather than to flavour it; this task falls to passum and defrutum instead. Alternatively, it might also have been a sweet wine, some of which may or may not have been reduced to a similar degree before fermentation.

A way out of this dilemma may be to find an inexpensive substitute, for example there are modern sweet wines which have cooked grape must added such as ‘Ambrato di Comiso’ from Sicily. However, some believe caroenum was a cooked syrup made at home. If a caroenum is made from a must taken from fresh grapes such as would normally be used to make a passum (i.e. a raisin wine, see below) then the must would be sweeter than usual. And when one-third of its volume has been boiled away with two-thirds remaining it would be a thin yet flavoursome syrup. I have also read on one website that caroenum was actually boiled down wine, and that sapa or defrutum was concentrated grape must.

This is in contrast to the excessive sweetness, thickness and colour normally associated with defrutum. Caroenum was used in the recipes as a bulk ingredient rather than to flavour or colour; that was often the role of passum and defrutum, which are made with red grape must. There are numerous sauces called oenogarum (see below) that contain no other form of ‘wine’ but caroenum and it could not therefore have been too thick or too rich. Andrew Dalby has pointed out that the original Greek term karyinos refers to a nutbrown colour, and this suggests to me that a white grape rather than a black one would have been the norm. To make a basic caroenum that will suffice for reconstructing these recipes, simmer a carton of white grape juice in a pan until you have lost one-third of its volume. Cool, return to the bottle and store. Alternatively, you can use the grape juice which you boiled to half its volume in order to adjust your fish sauce as a substitute for caroenum if you have made plenty. All these diverse wines and syrups – heavy raisin wine, rich and thick to add colour, and sweet thin syrups – were added to fish sauce and formed the basis of the ready-made sauce oenogarum.

Caroenum is also used to make 'oenogarum', a 'vinaigrette' made by mixing fish sauce, oil, wine, and spices.

Sapa

Many of you will already know that Italian saba, Latin sapa, meaning a grape syrup, is the origin of balsamic vinegar. Such syrups were left to age for longer than usual and they soured in the oak barrel producing the luscious vinegars we know today.  

Wines & Other Sweeteners

Passum

This was a dessert or raisin wine made with grapes that were either allowed to shrivel on the vine or dried on rush mats. More sweet must, from other grapes that had not been dried, was used to aid the pressing of the fruit. The result was then fermented and aged. It is not a process we can duplicate but there are modern varieties of sweet wine that correspond to this.

Passum was apparently developed in ancient Carthage (now in modern Tunisia) and transmitted from there to Italy, where it was popular in the Roman Empire. The earliest surviving instruction constitutes the only known Carthaginian recipe. It is a fragment from the Punic farming manual by Mago (agricultural writer) in its Latin translation by Decimus Junius Silanus (2nd century BC). It survives because it was summarised by Columella, De Agricultura 12.39.1:

Mago gives the following instructions for excellent passum. Harvest well-ripened very early bunches of grapes; reject any mildewed or damaged grapes. Fix in the ground forked branches or stakes not over four feet apart, linking them with poles. Lay reeds across them and spread the grapes on these in the sun, covering them at night to keep dew off. When they have dried, pick the grapes, put them in a fermenting vat or jar and add the best possible must (grape juice) so that they are just covered. When the grapes have absorbed it all and have swelled in six days, put them in a basket, press them and collect the passum. Next, tread the pressed grapes, adding very fresh must made from other grapes that have been sun-dried for three days. Mix all this and put the mixed mass through the press. Put this passum secundarium into sealed vessels immediately so that it will not become too austerum. After twenty or thirty days, when fermentation has ceased, rack into other vessels, seal the lids with gypsum and cover them with skins.

Malaga Dulce is what Sally Grainer recommends for replicating passum using Malaga Virgen and Malaga Moscatel. These wines can be hard to get in the plain ol’ liquor store and also might tend to be expensive. If you can find a Muscat wine it would work. Basically, what you want to find is a VERY sweet dessert wine — preferably a raisin wine.

Any very sweet dessert wines such as a heavy muscat or a heavier Sauternes will also do. Passum could be either dark or pale as long as it has that raisin flavour.

Date syrup

Date syrup was used as a sweetener in ancient Mesopotamia in place of honey. Roman sauce recipes regularly include dates but it is unclear whether they used the whole fruit, fresh or dried, or made a paste in advance to make life easier. Most recipes list the dates among the other liquids rather than with the nuts etc. and it may be a pre-ground thick syrup would have been used. You can find thick date syrup in health-food shops in Britain.