Wyeast Lacto Strain
I mentioned in another thread that I was surprised by some recent experiences with a wild strain. That strain is the Wyeast "Lactobacillus Delbrueckii" that many have used, and which I think many suspect was/is a component of the Roselare blend.
Messing around with it recently (trying to sour unpitched wort) it looked like it was producing quite a bit of CO2. But lactobacillus delbrueckii is homofermentive, and hence does not produce significant CO2. Surprising. And also annoying, since I had spent some time looking up information on l. delbrueckii and it appeared this strain might not be what it was labelled.
I emailed Wyeast about this and they were actually pretty responsive. After some discussion back and forth, I got an email today with the following information (and permission to share it publicly):
"You are correct, the strain you have received is a heterofermentative strain of lactobacillus and is not L. delbrueckii. We have recently replaced the L.del. culture with another strain of lactobacillus. Most likely it Lactobacillus brevis. It is a strain of Lactobacillus isolated from a Berliner weisse. Considering the source, we think it is brevis. We are
in the process of analyzing to make a definitive species determination. The packaging/marketing/technical info has been in the process of switching to this new strain. You will probably see this in the next package you purchase."
Also, "We sell this strain for the purpose of souring wort/beer. We try to provide the best strain we can find for doing this. This is why it was recently switched."
So, I give them credit for making this information available, but on the other hand it's their responsibility not to sell the strain as something it's not.
More broadly, how do we know the lacto, brett, etc strains we buy (from White Labs or Wyeast) are what they are labelled? It's a complex issue--sending strains out to get typed is expensive and might even make it unprofitable for them to even supply these strains. But at the very least, the strains should carry accurate labels, such as "souring lactobacillus" or some such.
Perhaps we should be emailing these companies and asking how they know their strains are what they are labelled. In the meantime, I think it's wise to assume (at most) that only the "lacto", "pedio", or "brett" portion of the strain name is correct.