Older Germans associate the word Herbstmilch with a surprisingly successful 1989 movie about the life of a young woman in rural Bavaria in the 1920s and 1930s. The eponymous dish was a staple of Alpine cuisine, a form of milk curd stored over the cold season and usually served as Herbstmilchsuppe with bread. It is thus not surprising that the Inntalkochbuch includes a recipe for this – the earliest reference we have by this name.
<<12>> Herbst milich zu machen
To make autumn milk
Put fresh milk into a pot, add sour milk (sawer milich) and stir it together, then let it stand until it becomes sour (sawer werd i.e. curdles).
Of course there is no reason to think this is the first mention of the method. Similar foodstuffs in various forms are referred to in earlier texts, usually associateed with rural poverty. Heinrich Wittenwiler‘s poem Der Ring includes a peasant feast at which characters gorge themselves on ‘sour milk’ until they vomit (on the time-honoured principle that poor people are disgusting and should be mocked). A landsknecht song of the early sixteenth entury makes the connection explicit:
With the peasant, I have to thresh and eat sour milk. / With the king, I carry full bottles, with the peasant, I wear coarse clothes. / With the king, I step onto the field bravely and march as a free hero, / (the clothes) chopped and slashed after the fashion of noblemen
Sour milk – eaten, not drunk, thus a solid food – was the mark of rural poverty, a common dish below the dignity of a warrior. There is good reason to think that it has roots going back all the way to the lac concretum (solidified milk) Tacitus identifies as the food of the Germanic peoples, so different from the salt-ripened, solid caseum of the Roman world.
The Artzney-Buch of Christoph Wirsung, a collection of medicinal recipes dating to 1568, gives us further details on the preparation of Herbstmilch:
Scald a new pot cleanly with hot water, rub it well with salt and make a hole in the bottom and a plug (Zaepflin) for it. After that, take new milk and curdle it like cheese. Let it stand from morning till evening. Then pull out the plug so that the water will flow out. After that, add a bowlful of curdled milk every day, according to how much or how little is in the pot. Stir it well and let the water run out every evening. You must also always salt the milk slightly as you curdle it (im rennen).
It would almost be surprising if Johannes Coler did not have something to say about so frugal a practice, and indeed the Oeconomia also includes instructions. He ascribes Herbstmilch to the Vogtland, an area on the Bohemian border close to Bavaria.
The Vogtländer make their autumn milk thus in early September
When they stir (rühren) or make butter, they take the butter out of the buttermilk, leave the buttermilk in the vat, and add sweet milk to it. They they pour warm milk over it and leave it standing in the heated room (Stube) for half a day or as long as they wish. Then they draw the plug (Zapffen) at the bottom of the vat and let the clear liquid (das lautere) run off. Then they place the thick mass (dz dicke) into a clean pot and set it in the pantry (Speise Alme oder Kammer) and use it. They also pour cold cream (Milchrahm oder Sahne) into it and whisk it (quirlens durcheinander), otherwise it becomes too thick.
Assuming that this does indeed describe the same thing (which is not always a given), the reference to keeping it warm (the Stube was the only heated room in most homes) and the gradual addition of more milk to build up the quantity suggest a bacterial culture rather than rennet or acid as the thickening agent. That would make it similar to modern Dickmilch or clabber. Most of Central and Eastern Europe has dairy products like this.