Digging through some Dutch medieval folio’s I came across these two intriguing tidbits in the manuscript Hs. Sloane 345 which is kept at the British Museum in London. These two recipes show how medieval brewers dealt with beer and wine going off, which likely happened much more often as storage in wooden barrels is not an oxygen free environment, and many brews were short brews – ready to drink quickly but not made for aging.
To make wine good [again].
Recipe .ij. a handful of pits of blue grapes, and also some winestone and half also some white [or weed] ashes and the recipe .ij. a handful of small flint stone [gravel], and put this together in a spoiled wine, so that it becomes good again.
My two cents on how this would work:
Grape seeds are rich in vitamin E, flavonoids, linoleic acid, and OPC’s which are powerful anti-oxidants. Vitamin E is used as a preservative in food and cosmetics.
Winestone, or the tartaric acid sediment at the bottom of a wine cask, is the naturally occurring form of tartar. Tartar is used in wine as a pH stabilizer.
White ash, or well burned potash, makes an alkaline solution which has anti-bacterial properties. The translation could also mean weed ashes, which could make sense if grass, straw or bean stalks are ashed as they were known in period to yield a strong lye, similar to using white ashes (which can be made of any hardwood and would be easier to source at for instance a smithy). Potash in dilution with crude tartar by way of a chemical reaction will precipitate cream of tartar. Tartar is used as a pH stabilizer but due to its buffering effect cream of tartar can also be used as a natural baking powder in wine making (as it has the least amount of lingering taste).
And if this is added through the tiny hole of a wine barrel, then the gravel would make a great mixing agent if the barrel is plugged up and rolled around!
About beer so it won’t sour.
Recipe .j. a handful of mustard seeds, and one handful wheat, and throw in a ton of beer and stir it well, this way it won’t go sour.
Not only are mustard seeds a great source of vitamin A, C and K, making it an excellent antioxidant, the seeds also contain good amount of sulfur which is known for its anti-fungal properties. It’s like a medieval campden tablet!
While wheat contains large quantities of minerals, giving the yeast a boost over invading bacteria, it is also very rich in vitamin E, a rich anti-oxidant and natural preservative.
Who’d have known adding gravel and mustard seeds to spoiling brews would make sense!
Recipes come from Medische en technische Middelnederlandse recepten. Een tweede bijdrage tot de geschiedenis van de vakliteratuur in de Nederlanden. (Medical and technical Middle Dutch recipes. A second addition to the history of trade literature in the Netherlands) by Willy L. Braekman (ed.), and printed by the Koninklijke Vlaamse Academie voor Taal- en Letterkunde (Royal Flemish Acadamy of Language and Literature), Gent 1975; © dbnl 2004. © Translations by Susan Verberg, 2016.
For general information on ingredients:
For the transcriptions of the middle Dutch recipes: http://bookeofsecretes.blogspot.com/2016/08/winestone-mustard-seeds-gravel-to.html
For the complete manuscript including many other folio’s: