Fermentis W-34/70 may produce satisfactory results for a lot of brewers, but not for me. Up until this pass through the hobby, I fermented almost exclusively with cultures I either received on slant or plated for singles and put on slant, which makes me a difficult customer to please. Everyone keeps talking about how great dry yeast is today, but the convenience factor must outweigh the small differences in the final product that matter to me. That is the nicest thing I can say at the present time. I just kegged a batch that I fermented with a direct pitch of Imperial L28 Urkel (which cost less than two packages of Ferments W-34/70 at my LHBS). My girlfriend who is completely new to brewing noticed how much smoother this batch was while still green than the batch fermented with Fermentis W-34/70 was after lagering. Both beers had the same gravity and were fermented using the same basic fermentation protocol. One beer came out of the primary drinkable. The other, well, I will be glad when the keg is empty. The W-34/70 batch still has a faint phenolic note and a definite lemon-like sourness, both of which my non-BJCP-trained girlfriend picked up on. Although, she does have an amazing palate due to decades of gourmet cooking.
I guess the moral of the story is that if Fermentis W-34/70 is working for a brewer, he/she should stick with it. However, until I find a dry lager culture that performs as well as liquid yeast, let alone as well as cultured yeast, I plan to stick to liquid and cultured yeast. Considering the small number of viable cells in an 11g package (at most, 55 billion for most dry cultures), liquid yeast is price competitive with dry yeast. I am willing to give Diamond Lager a shot because, even though it can be slow to start, BRY-97 is the sole dry culture I have used that comes close in performance to liquid or cultured yeast. Given the choice between the two dry yeast propagators, my bets are hedged on Lallemand at this point. Every brewer needs a “just in case” culture.
By the way, my favorite all-time lager yeast culture is NCYC 679. I acquired it on slant from the NCYC during my first pass through the hobby. I believe that this culture may be from the defunct Stein Brewery in Bratislava. If S-23 is a fruity lager, I suspect that NCYC 679 is related. It is not ale fruity, but it does produce an interesting, subdued ester profile, even when fermented cold.
NCYC 679
Saccharomyces pastorianus
Pre 2011 Name
Saccharomyces pastorianus
Depositor
O. Bendova, Prague
Deposit Date
January 1966
Habitat
Lager production strain from Bratislava brewery.
The one time I tried Diamond Lager Yeast it ended up a complete diacetyl bomb. Granted, I only pitched one pack into 1.056 wort which would be under-pitching. Nothing I did could salvage this beer and I dumped it. Maybe I should give it another try and pitch more yeast. W-34/70 has worked fine for me the times that I have tried it, but like others have noted it took a long time to clear.
I was a die hard fan of anything from Wyeast. That was the only yeast I used…until W-34/70 and S-04 were found. Now I pitch 4th, 5th, 8th generations of this yeast, with spectacular results.
Dry yeast today is light years ahead of where it was a decade ago. And I was a liquid yeast “snob” in a previous life.
Therein, lies one of the big red flags with this culture for me because the reference culture, W-34/70, is not powdery. It is flocculent. That means the Fermentis W-34/70 has to be a mutant. It may not start out that way as a seed culture, but mutation is definitely occurring under aerobic propagation under the Crabtree threshold in a bioreator at Fermentis, that is, if Fermentis W-34/70 is actually W-34/70.
Fermentis W-34/70 fits the W-34/78 fermentation profile more so than the W-34/70 profile, but even then, W-34/78 is not powdery. Below is a link to downloadable PDF that is the document for TUM 34/70 and TUM 34/78, which are W-34/70 and W-34/78.
What is a “powdery” yeast strain? Well, it is a yeast strain that has lost its ability to flocculate. A lot of people confuse flocculation with sedimentation. Even non-flocculent yeast strains will eventually sediment. They just take longer because they do not aggregate into flocs, which increases the rate of sedimentation. Some yeast strains trap CO2 gas when they aggregate. The trapped CO2 gas causes them to rise to the surface. We refer to these strains as true top-croppers.
By the way, the English translation of the acronym TUM is Technical University of Munich. The TUM school of life sciences is located on the Weihenstephan campus.
I bet that if you spent any appreciable amount of time brewing with cultured yeast that was propagated from a single colony on a plate or a slant that was propagated from a single colony on a plate, your opinion would be differentt. I pick up on things with liquid strains that other people miss and they are significantly less off-flavor prone than dry yeast. I have picked up on off-flavors from every modern day dry yeast culture. BRY-97 has come the closest to matching liquid. Most people would not believe how much cleaner cultured yeast can be than dry yeast or even commercial liquid yeast. It is what kept me maintaining a yeast bank on agar slants all of those years. It is why the bigger craft brewers who can afford a quality lab brew with cultured yeast. One does not have hold a fermentation at an artificially low temperature with cultured yeast to achieve a clean product. Cultured yeast is better behaved.
This mirrors my situation to a tee. Before I took a roughly 15 year home brewing sabbatical I was a 100% user of liquid yeast. Since I returned to brewing about 5 years ago I’ve been using about 90% dry yeast and 10% liquid yeast.
Some of this may also just come down to personal taste, right? I know some brewers who are very, very good and meticulous brewers so I assume their process is good. But they might use a yeast strain (say Omega Bayern) and come back later and say that they just don’t like this yeast. Could that be the case with 34/70 too? I’ll admit that I rarely use dry yeast. That run of Diamond beers I made was a complete fluke but I liked the beer and the yeast was performing well. Typically I have Omega Bayern, WLP940, WY2124 or WY2308/WLP838 running here. The dry yeast is usually just for emergencies or spontaneous brewing.
Genetically they are very closely relatedl but since they’re different forms from different companies, there will be differences. No different than US05/001/1056
Not really blaming the yeast. Like I stated, I only used it once and I probably didn’t pitch enough with one packet. I had higher than expected efficiency and an OG of 1.056. I might try it again to see if I get better results.
Seriously? A lot of brewers are blind to yeast induced off-flavors. That does not make them bad brewers. It makes them unaware brewers. In the land of the blind, the one-eyed man is king.
My take away from all this is that if I want to experience the cleanest lager fermentation I need to culture my own. Even wyeast/white labs may be mutated pitches. Dry yeast most definitely is mutated?
Couple this with all the LODO information and I hope I have time someday to brew a good beer…for once.
I was trying to be funny with my last comment and I guess it really wasn’t. My point is that if I use something for the first time and it turns out bad enough to dump it, then I’m reluctant to use it again. Who knows why this batch had an awful diacetyl off flavor? Too many variables to pin it down to the cause. I’m not hypersensitive to it, but this batch was noticeably “butter” and not worth keeping around.