I've searched everywhere.
No Wikipedia page.
No information on NCBI.
I searched all occurrences of 34/70 in some primary research articles!
The best I've found is this brewery forum where someone asked the same question.

And the user rockfish42 answered:

No idea why they use that number, but it's the catalog number at Weihenstephan's hefebank.


2 Answers 2


I went to the Yeastbank website at Weihenstephan for some info. The keyword here is "Stamm," which is German for stem, clade, clan, or strain. So, I would take this to mean that the 34/70 is an isolate (#70) of strain 34. Two of 34/70's strengths, according to the link above are it makes clean beer and gives a pleasant taste profile due to its low yeast-like aroma in the finished beer. I can attest to that firsthand, having had on numerous occasions the pleasure of partaking of Weihenstephaner beer in its home city of Freising.

  • $\begingroup$ That seems like a reasonable explanation. It reminds me of a lot of mammalian cell lines that go by common names (PC-12, Ins-1, Min-6, P19) that get a name based on the isolate number they came from in the original experiment. $\endgroup$
    – user560
    Apr 9, 2012 at 19:10

I am not sure why you say there is no information... a quick Google search returned a few interesting pages...

In this paper:

Progress in Metabolic Engineering of Saccharomyces cerevisiae - Nevoigt, Microbiol Mol Biol Rev. 2008

the author says:

The identification of the entire genomic sequence of a commonly used lager brewer's yeast strain, i.e., Weihenstephan Nr. 34 (34/70), represents a breakthrough in the molecular analysis of lager brewer's yeast.

So, it would look like 34/70 is just a catalogue number, with no specific meaning.

Curiously, according to the Wikipedia page on Saccharomyces pastorianus:

S. pastorianus never grows above 34 °C (93 °F)

So, I cannot exclude the hypothesis that 34 could come from there although, well, I personally propend for the catalogue number.

Other interesting links:

The paper about the S. pastorianus genome sequencing:
Genome sequence of the lager brewing yeast, an interspecies hybrid. - Nakao et al., DNA Res. 2009

An article comparing two different strains of S. pastorianus, 34/70 and 34/78 (again, catalog number hypothesis seems to be the most obvious explanation)

Molecular species of phosphatidylethanolamine from continuous cultures of Saccharomyces pastorianus syn. carlsbergensis strains. - Tosch, Yeast. 2006

The NCBI taxonomy page (entry #520522)

  • $\begingroup$ That was a lot of effort for an answer that contained no new information. The question already said that 34/70 is the catalog number. The question was what the 34/70 means. And no it is not the temperature at which it starts to grow, that would mean Stamm W 195 starts to grow at 195°C !! Larry_Parnell's answer is much better. $\endgroup$ Apr 9, 2012 at 15:05
  • $\begingroup$ No, the yeast stops growing at 34, so that's most probably just a coincidence, as I said. As for the new information... your question does not contain any of this and you said there was no Wikipedia or NCBI page, so I pointed out that there are in fact such pages, that's all. If the other answer is better accept that, I surely won't be offended. $\endgroup$
    – nico
    Apr 9, 2012 at 15:06
  • $\begingroup$ Yes my question said that it was the catalog number. See the quote. There's no wiki page for Saccharomyces pastorianus Weihenstephan 34/70, and I didn't say there's no NCBI page, just that the NCBI page didn't have any information about the 34/70. Sorry that I misread it as 'starts growing' rather than 'stops growing' , but the argument still stands the same =) $\endgroup$ Apr 9, 2012 at 15:14
  • $\begingroup$ It seems like @nico was trying to help identify what was known from these public sources (NCBI, Wikipedia) for others that read the question as well. He was able to come up with the same informaation you seem to have found, and though he did not find a definitive answer as to the history of the name, it is relevant information. :) $\endgroup$
    – user560
    Apr 9, 2012 at 19:09

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