This is one of the recipes in the Mondseer Kochbuch that has no parallel in the Buoch von guoter Spise, and I must admit I do not fully understand how it is supposed to work:
86 Milk with crawfish, or a spoon dish (gemüß)
If you wish to prepare a good spoon dish (gemüß), take milk in a clean pot and set the milk by a fire. Take the crawfish and cut away their eyes, but leave the rest of the crawfish whole and wash them quite clean. When you have washed them, throw them into a mortar and pound them very small. When they are half pounded, press them out with a clean cloth so that their juice passes through it. Then pound them again very thoroughly. Then take pure milk that is raw and pour it into the mortar. And (take) the juice that you pressed out before and pour it in with the first, stir it together, and strain it cleanly through a sieve. Pour it into boiling milk altogether and it will congeal. When it has congealed well, pour it out on a clean cloth. From this same, you can prepare more than one dish. Take it and throw it into pure butter in a pan and fry (röst) it, thus you have a pure food. If you wish to have it sweet, take honey and add it, thus it will be sweet. If you have sugar, you do not need honey. You must not put the sugar into the pot. When you have prepared the food in the (serving) bowl, strew it with the sugar. This is how your food is prepared.
87 A cheese of crawfish and milk
If you wish to prepare a good cheese of that which is on the cloth in the other (recipe), take the cloth twofold (i.e. two layers) and tie it shut and lay it on a table. Lay stones on top of it and weigh it down well. Untie it, and it is like a cheese. If you want to serve it whole or if you want to slice it and serve sauce over it, take bread and toast it, and (take) parsley together with vinegar and wine, or prepare another sauce with eggs, as you please.
I freely admit that this recipe is mainly strange to me. It very likely does not have much to offer in terms of flavour, but the technique is intriguing. Of course much depends on the unstated facts here. If we assume a loose cloth and a high proportion of crawfish to milk, this could be a Mus dish consisting mostly of throroughly mashed crawfish meat, but I don’t think that is the idea. Rather, there is probably something in the – for want of a petter word – crawfish juice that causes the hot milk to congeal. I do not know enough about crustacean biology to say what it could be. The process might depend on denaturing proteins, which would give the liquefied crawfish the same role that eggs often play in similar ‘roast milk‘ recipes. That would require a large quantity of crawfish and likely produce a red colour from cooking particles of the shell that passed through the cloth. That would be intentional, as another recipe from the Inntalkochbuch attests. Alternatively, there might well be somew kind of enzymatic action at work that curdles milk protein. I am not suire whether I would want to try this out, but at this point it has no high priority and I would not even know where to get raw crawfish. So I will park it in a holding pattern for a while.
The Mondseer Kochbuch is a recipe collection bound with a set of manuscript texts on grammar, dietetics, wine, and theology. There is a note inside that part of the book was completed in 1439 and, in a different place, that it was gifted to the abbot of the monastery at Mondsee (Austria). It is not certain whether the manuscript already included the recipes at that point, but it is likely. The entire codex was bound in leather in the second half of the fifteenth century, so at this point the recipe collection must have been part of it. The book was held at the monastery until it passed into the Vienna court library, now the national library of Austria, where it is now Cod 4995.
The collection shows clear parallels with the Buoch von guoter Spise. Many of its recipes are complex and call for expensive ingredients, and some give unusually precise quantities and measurements. It is edited in Doris Aichholzer’s “Wildu machen ayn guet essen…” Drei mittelhochdeutsche Kochbücher: Edition, Übersetzung, Quellenkommentar, Peter Lang, Berne et al. 1999