Not wine, nor vinegar

Grapes being pressed to make wine ... or verjuice (16th century)Literally verjuice means 'green juice'. It is the juice from unripe grapes, unripe apples, sorrel, goose berries, whatever, as long as it is sour. It is a common ingredient in medieval recipes, and even in later recipes up to the seventeenth century. Then it kind of got forgotten, until these days when it is making a slow come back. There are even commercial producers of verjuice again!

The taste of verjuice

Platina cites Macrobius' description of the taste of verjuice: Vinegar is sharper than verjuice ("acetum acerbius acore est", edition, II.26).
Verjuice will become milder as it gets older, and it will not keep indefinitively. It was used frequently in the Middle Ages. It could happen that in the summer the old stock of verjuice had gone off, or was simply used up. There are several recipes for 'summer verjuice', that were meant to tide things over until the new verjuice from grapes was again available. But this new verjuice was often too sharp in taste. If there was any old verjuice left, both kinds of verjuice were often blended (See the Ménagier de Paris, edition p.260).
This makes me wonder whether commercial verjuice is not more like old verjuice than new, because it has a very mild taste. You can even drink it like a refreshing grape juice.
Because verjuice was often not available the whole year round, alternatives are mentioned, like vinegar, gooseberry juice, lemon juice or rose water (which amazes me, because that isn't sour at all). In Northwest-Europe verjuice was probably made from apples rather than grapes. So apple vinegar may be an excellent alternative if you can't buy or make verjuice.

The harvest of grapes from my gardenMake your own verjuice

In my garden grows an exuberant grape, a blue Frankenthaler, that has yielded quite a harvest this year (2006). So I decided to make my own veruice. After reading the discussion about verjuice on Florilegium and leafing through some historical texts I have chosen to proceed as follows:

Because the grapes already started to turn colour I harvested part of them on August 22 (2006, see picture on the left). First I shook the bunches firmly, to get rid of the little creepy crawlies. Then I plucked the grapes from their stems, very quickly and roughly. The grapes were NOT rinsed, because it seems that the natural yeasts on the grape skins will cause a light fermentation (it will never be much, because there simply isn't enough sugar).
Then the grapes had to be pressed. I don't have a juice extractor, and everybody around me who has ever had such an appliance had gotten rid of it a long time ago. It seems juice extractors are not popular.
I started the old-fashioned way by using a purée sieve, but soon I decided to just throw the grapes into the blender for a few seconds before putting them into a sieve under light pressure to release the juices. The first result was a brightly green, turbid juice that tasted very sour, but distinctly of grapes.
The next step was to leave the juice with some dry-roasted sea salt for a day and a half, covered with a folded linen cloth. There were no airbubbles left, so I presume that whatever fermentation had taken place was finished.

Home made, fresh verjuiceThe last step was to filtre the juice through fine kitchen towels, and freeze it in ice cube holders. The juice never became completely clear, even after filtering three times (see piture on the right). When I tasted the end result, it was still more sour than commercial verjuice. But the taste of grapes was still there.
Recipes with verjuice on this site: Heavenly blue sauce, Meatballs in head-lettuce, Eggplants in eggplant sauce, Marinated veal cutlets.

Grape varieties and when to harvest for verjuice

You can't make verjuice of just any grape. Sources mention that there varieties that are good for making verjuice, and varieties that yield excellent wine, but there are no varieties that are good for both.
One of the grape varieties that is praised for its qualities for verjuice is the Gouais. This white grape is almost extinct (because not commercially useful), but its DNA is present in several new grape varieties that resulted from crossing it with the Pinot.
On Florilegium the discussion on when to harvest grapes for making verjuice has resulted in: "pick them before the grapes are ripe and start turning colour", which is interpreted as somewhere between the beginning of August and the beginning of September. I followed these directions. (Especially as it was already well into August before I even thuoght of making verjuice).
But from Pliny's Naturalis Historiae (edition 12.60) and the Ménagier de Paris one could conclude that grapes for verjuice must be picked earlier in the year, at the beginning of July.
Pliny mentions that the grapes must be the size of chick peas, and be picked before the dog days (after July 6th), the Ménagier advizes to blend old and new verjuice because "in july the ood verjuice is very weak and the new verjuice is still too green". So new verjuice was already available in July.

Verjuice in summer and in winter
Gheeraert Vorselman has provided us with two recipes for verjuice in his Nyeuwen coock boeck ('New cook book', 1560, edition recipes XVI.22 and XVI.23).
The recipe for summer verjuice was well known. An older version can be found in the Middle Dutch manuscript KA Gent 15.1. In Le Ménagier de Paris from the fourteenth century there is also a recipe for summer verjuice, which uses instead of vinegar and wine white (which means old) verjuice ("Vertjus d'ozeille", edition p.258). This kind of defeats the purpose of making summer verjuice because the old verjuice has run out.
The recipe for winter verjuice can also be found in the Medecynboec from 1593 by Carolus Battus(edition). The salt is not roasted, and the verjuice is boiled to conserve it.

Om groen verjuys te maken tsomers.
Neemt de tweedeel sulckerbladeren ende het derdedeel petercelie ende stoot dese tsamen ende dan doet dat met wat wijns ende azijns door eenen stromijn. Ende oft ghi geenen sulcker gecrigen en cont, neemt daer voor wijngaertcrammen.
To make green verjuice in the summer.
Take two thirds sorrel leaves and one third parsley. Grind these together, and strain them with some wine and vinegar through a sieve. And if you can't get any sorrel, take vine leaves instead.
Om winterverjuys te maken.
Neemt verschen most van onrijpe druyven, ende doet daer in geroost sout, so matelic dat daer na niet en smake, ende dan doeter in een deel onrijpe mispelen.
To make winter verjuice.
Take fresh must from unripe grapes, and add roasted salt, so little of it that it won't be tasted, and add some unripe medlars.

All descriptions of ingredients

MedlarMedlar - The fruit of a small tree (the Mespilus germanica) that is related to apples. The fruit resembles an apple, but what is at the core of the apple, is visible at the underside of the medlar. They are, even when fully ripened, unedible, they are too firm. The saying "rotten as a medlar" comes from the fact that only when the fruit is brown and soft through fermentation it can be eaten. And even then many people are repulsed by the medlar.
Medlars used to be added to must to enhance taste and durability, which is probably also why Vorsselman advizes added medlars to verjuice.
I didn't use medlars in my verjuice. Maybe next year.
Must - This is fermenting grape juice. When ripe grapes are pressed, the juice will ferment (through natural or added yeast). Must can't be kept in a closed container, the gasses must be able to escape. When the first, hefty yeasting is over the must will ripen into young wine. Must is only available just after the grapes are pressed after the harvest, for a short period. I once drank it in october in Wallis (the wine province of Switzerland). It was frizzy and refreshing in taste.

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