I can only remember hearing of the beer in one context: as a recommended source of yeast for Berliner Weisse. The recipe is fairly intriguing. What with its mix of grains and the weird way the hops are processed. You take a look:
"Brewing Kotbusser Bier according to Hermbstädt
This beer is very similar to Broyhahn, but is not solely from barley malt, rather prepared from a mixture of barley and wheat malt, along with an additions of hops. The method used to brew the above beer is not known, however, Hr. geheimer Medicinatrath Hermbstädt insists that, through experiments, he has succeeded in producing a beer that could be set alongside a true Kotbusser. For a brew of 2000 Berlin quarts [2,290 litres], the following materials are required.
1) 25 Berliner bushels (1500 pounds [750 kg]) pale barley malt.
2) 20 Berl. bushels (800 pounds [400 kg]) pale wheat malt.
3) 5 bushels (200 pounds [100 kg]) oats.
4) 6 pounds [3 kg] of the best hops.
5) 20 pounds [10 kg] honey.
6) 20 pounds [10 kg] raw sugar.
After the malts have been ground and mixed well, they are doughed in with 3000 Berl. Quarts [3,435 litres]of water at 36 ° R [45º C]. and well worked through, so that every part is completely permeated by water. For the second infusion, take the same quantity of boiling water, mash well for a full hour long, and give the mash a half hours' rest in a covered mash tun and before drawing off the wort, which is then evaporated down by a gentle boil to 2000 quarts [2,290 litres]. After the honey and raw sugar have been dissolved in the wort, it is passed through straw, the hop extract is added and it is cooled in the coolship down to l4 ° R [17.5º C]..
For the purpose of the fermentation it is put into a fermenting vessel with 10 quarts [11.45 litres] of yeast and when the yeast has reached its highest level, it is removed and the fermented wort taken off the sediment of yeast and transferred to the barrels stored in the cellar. When the ejection of yeast from them slows, the casks are bunged. After 24 days, the beer is usually drinkable.
The hops are subjected to two extractions in the Hopfenblase [literally hop bladder], the first time with 40 [46 litres], the second time with 25 quarts [29 litres] of water and each time for 80-10 hours. The residue from the second extraction is pressed out. The spent grains are immersed again in 1000 Berlin quarts [1,145 litres] of boiling hot water and the recovered wort is boiled with the pressed-out hops for half an hour, again passed through the spent grains, cooled, pitched with 3 quarts [3.4 litres] of yeast and made into Kovent."
"Grundsaetze der Bierbrauerei nach den neuesten technisch-chemischen
Entdeckungen" by Christian Heinrich Schmidt, 1853, pages 446-447.
One small point. I'm not sure if the pounds are metric or Prussian. Prussia swapped officially to the kilogram in 1855. Not that it makes a great deal of difference, as they were very similar in size. 1 Prussian pound = 467.711 grams. And, just for reference, 1 Prussian quart = 1.14503 litres.
The proportion of the grains was 60% barley, 32% wheat and 8% oats. I got the OG to around 1090 with my calculation, which seems very high. (The only analysis I have of a Kotbusser gives an OG of 1026.) The hopping rate is very low. The brew was about 14 imperial barrels.Six pounds of hops gives a hopping rate of just 0.43 lbs to the barrel. Not sure what effect the small amount of honey and sugar would have. It seems way too little to me to be worth the trouble.
There are more recipes in this book. Perhaps they will follow. If I can be bothered to translate them.