Berliner Weisse yeast

This was a fun little article to come across. And not just because it references Schonfeld, the VLB's top-fermentation specialist. But also on account of a feeling of smugness that comes over me knowing that I have a slightly deeper understanding of the topic than the author. Purely because of the advances that have occurred in brewing science in the last 100 year.

The Pitching Yeast of Berlin White Beer.
According to Schonfeld (Wochenschrift für Brauerei), the pitching yeast of Berlin white beer (Weissbier), occupies a unique position among yeasts, inasmuch as, instead of being carefully protected from bacterial infection, it owes its value precisely to its high content of a special kind of bacteria, namely, the rod-like lactic acid bacterium. The usual proportion of yeast cells to bacteria is 4 to 7 to 1. The yeast itself is also characterised by unusually high fermenting power, the attenuation at the close of primary fermentation averaging 70 to 75 per cent., as compared with the 35 to 40 per cent, of ordinary beers.

At one time the brewers did not prepare the pitching yeast themselves, but obtained it from the retailers; but, as this yeast is very liable to degenerate, another source had to be drawn upon, namely, the yeast used in the production of Kottbus bitter beer. At present, however, it has become the custom to prepare the pitching yeast in the brewery, and it has now attained such fixity of type as to be capable of continued use without losing its character.

The lactic ferment is probably of the same origin as those present in sour milk and the acid distillery mash, modified into the present variety by long exposure to the particular environment, and so fixed in type as to be no longer reconvertible. Although the final mashing temperature of this beer is too high to permit the reproduction of similar bacteria, it is probable that, before the employment of the thermometer, the final temperature was appreciably lower; and, as it has always been the custom to work with an open mash-tun during the filtration of the wort, it seems feasible to assume that the lactic bacteria first found their way into the pitching yeast in this manner, and that they have since become acclimatized to the conditions prevailing in the brewing process.
The Brewers' Journal vol. 38 1902, July 15th 1902, page 436.

This is the bit that struck me: "The yeast itself is also characterised by unusually high fermenting power". Why? Because the very high attenuation in Berliner Weisse isn't as a result of the primary pitching yeast. But of the Brettanomyces that kicks off during secondary fermentation. As this was before Clausen revealed the secondary yeast's existence, you can't really blame the article's author. Especially as, even after everyone knew about Brettanomyces, no-one niticed it in Berliner Weisse until the 1980s.

Did the Lactobacillus really originally get picked from the environment? Sounds feasible to me.