"Lyon Brown Beer.
A worthy side piece to (bottom-fermented) Kulmbacher beer is the (top-fermented) Lyon brown beer, - its colour is dark brown and its taste extremely rich. However, these properties are achieved in a very different way than with Kulmbacher beers.
The malt gives a snow-white flour body. The brewing method is pure infusion (compare "Bierbrauer X, p. 168). The boiling wort is skimmed, which is apparently unnecessary here.
But then, calf's feet (one per Zentner [100 kg] malt) are added along with the hops and first boiled for nearly 3 hours. The kettle, which has a dome-shaped lid with a safety valve which can be hermetically sealed, is now closed, the fire covered with ash and the wort steamed for about 5 hours under pressure, ie kept at a temperature higher than boiling point. As a consequence, not only is all the glutin broken down and converted into browned proteins, but also the animal glue from the calf's feet breaks down in a similar way, making the wort a deep brown colour, and the foundation is laid for an excessive fullness.
The wort, which has been cooled to 16º, is fermented with a top-fermenting yeast in small barrels (so that the temperature does not rise too much). Two days after pitching the yeast, the beer is completely clear, is filled into bottles and soon acquires the necessary conditioning.
Comparing the taste of bottom-fermented Kulmbacher beer with top-fermented Lyon beer, it turns out that the latter, for reasons already explained, has a lower degree of attenuation and therefore has a sweeter taste."
"Schule der Bierbrauerei" by G.E. Habich, published in 1865, pages 401 and 402.
Calf's feet. Never seen them amongst the ingredients before. Boiling under pressure is a new one to me, too. Definitely an interesting way to colour a beer, but it sounds more like hopped stew than a beer.
I know I promised something about Berliner Weisse. Don't worry. It's coming. When I've translated everything.