Gose and coriander

Leipziger Gose is a spiced and soured wheat beer.

Gose brewery in Döllnitz around 1860 (source) ... today

The two locally produced ones contain coriander.
Which is supposedly thrown in the brewcettle at flameout. 

But why, since when and where did the use coriander or other spices?

lets try to sum up some facts:

1. There is no data about coriander in the "Goslarer Gose"

2. According to Heinrich Steckhan in the 19th century they did use wormwood and cinnamon (they infused a bag containing the spices with the still hot? wort to make their premium-style Gose "Frehmtenbestekrug")
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3. Hermbstädt (1826) does not mention any spices at all. (Goslarsche and Sandersleber Gose)
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4. Zimmermann (1842) writes about coriander as a late edition for "Weizenlagerbier" (with cloves and cinnamon), for Burton ale (with grains of paradise), for "Weißes Bitterbier" (white bitter beer) a pale top fermenting beer made from all barley in bavaria and for bock.
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5. Armann (1859) mentions coriander besides cinnamon and cloves as an addition (during fermentation) for "Weizenlagerbier" (wheat lager beer)which he distinguishes from Gose and Broihan.

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6. Leuchs (1867) describes coriander as a valued beer-spice, especially for "Bock".
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7. According to Adolf Goedecke (2005) owner of the Döllnitz manor, the original recipe contains different spices of which coriander is only one. The Goedecke-recipe is only one of probably dozens of differing recipes brewed once in and around Leipzig, but it was selling well. It was possibly created by Phillip Ledermann who came to Döllnitz from Goslar in 1823.
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