The Greening of Cervisia

In a 1914 issue of The Western Brewer, German-born Leopold Nathan, designer of the famous cylindro-conical fermenter, said that American lager typically had green flavours.

The German term for this is Jungbuket, see a discussion on the taste, here, a few years ago from The Brewing Network. Indeed Nathan used the very term in English, “young bouquet”.

Beer Bottle.

Nathan argued that a well-matured lager, as in Europe, did not possess the taste. In the same discussion, he said a “tinge of youngishness” was acceptable when krausen (young fermenting beer) was used to carbonate, but he felt the sulphide taste in American beer was much more pronounced.

The krausen process, he said, should only be used with old, well-matured (lagered) beer. In other words, just a touch of green taste results as the krausen was added to a much larger bulk of beer which had none. Indeed he thought the result beneficial.

Nathan said American beer was green because CO2 collected from the fermentation and re-inserted in the beer still retained aromas of fermentation.

The implication was the beer was not permitted to undergo prolonged lagering and carbonate itself or receive a fillip with a final krausen.

Nathan also said on the same trip to America that in Pilsen, the beer was “pumped” to the lagering vats to rid it of any lingering carbonation. This perhaps explains why Pilsner Urquell to this day has no green taste. The word pump implies an agitation, to allow residual CO2 to lift off.

It was this sulphide taste – old vegetable, burnt match, etc. – that the Clausen brewery in New York proudly advertised (1888) its beer did not have. But evidently it still characterized much American beer 25 years later.

Of course, it is hard to know how much green aroma Nathan was referring to compared to modern lagers. One thing I do know: on a trip to Munich some years ago, I found the taste very strong in most helles, much more than in Heineken, say, or numerous craft lagers.

This means I think an interesting reversal has occurred: what Nathan objected to here has become part of the beer palate on his own turf. The reasons would be, abandonment of open fermentation and short lagering periods – the same circumstances which attended increasingly American brewing after 1900. Possibly too shorter boils in the kettle have an influence, as a longer boil can distill off these tastes, if allowed to vent that is.

Nathan’s fermentation system, now usual around the world, used enclosed fermentation to be sure. This would trap objectionable odours not eliminated in the boil, but he claimed to eliminate them by a “washing” method, also described below.

And so in our day, as in his, some lager has the taste (different intensities), and some does not. For lager which does not, some element of the process must explain it: the yeast strain, the malt, CO2 washing or its modern equivalent, or something else. From a homebrewer’s perspective, see this discussion on how to address the issue, which broad brush appears valid commercially, too.

We should note, finally, Nathan’s comment:

I have come to believe that people become so used to the taste they hardly notice it any more.

This may be the true explanation why the Jungbuket taste endures to our day.

Note re images: the first image above was obtained from O. Berk’s packaging solutions website. The extracts from the Western Brewer are via HathiTrust and the links are provided in the text. All intellectual property in or to the images belongs solely to their lawful owner or authorized user. Images are believed available for educational and historical purposes. All feedback welcomed.