[Saccharomyces]

+1. Clean enough to be healthy, but definitely evidence of being lived in.

You are former military and so I am.  While you may not be able to eat off of your floor,  I seriously doubt that your home comes close to what I am talking about.  I am talking about homes where one's shoes stick the floors and one's hands stick to the counters.  Homes where the bathrooms are so filthy that they make the dirtiest gas station bathroom one has ever encountered look clean.  Houses where takeout food boxes are strewn everywhere and lord only knows how long their contents have sat rotting.  A large percentage of the brewers who have helped me improve their fermentation quality live in places that are at this level of unkemptness or slightly above it.  The reason why the military drives cleaning home is partially due to public health, but it is to teach young service men and women to pay attention to detail.  Brewing consistent beer is about paying attention to detail, every little detail.

[Saccharomyces]

Don’t all dry yeast packaging disclose that they have some wild yeast and other microbes in them?  Has any commercial yeast producer put such information on liquid yeast packaging?  It would seem to me that serially repitching always risks contamination, genetic drift and petite mutants... but I suppose that plating and culturing from slants in sterile conditions (positive vent pressure and sterile loop) might avoid that issue.  I have simply reduced my repitch numbers lately to avoid the issue - rarely more than 5 batches.  Maybe I have just been lucky.

It is not that the producers do not disclose contamination figures.  It is at what level were those figures determined?  Unless the cultures tested were from the 11g packaging level, they should be taken with a grain of salt.  It is a lot harder to reliably fill 11g packages contamination free than 500g bricks just as it is a lot more challenging to reliably fill LBHS retail trade packages of liquid yeast than it is 1L or larger professional pitches.

[BrewBama]

You have a ton of speculation, anecdotes, and variability in your justification that dry strains aren’t what they are.

I am not sure how you have experienced a different performance in your wort inoculated with a different pitch rate of 34/70 than the mfr does in their standardized wort — which can be totally different composition that can easily produce different results (therefore comparing apples to oranges) — then jump to a completely a different strain’s analysis as proof of an assertion that dry strains aren’t what the mfr says they are.


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[RC]

+1. Clean enough to be healthy, but definitely evidence of being lived in.

You are former military and so I am.  While you may not be able to eat off of your floor,  I seriously doubt that your home comes close to what I am talking about.  I am talking about homes where one's shoes stick the floors and one's hands stick to the counters.  Homes where the bathrooms are so filthy that they make the dirtiest gas station bathroom one has ever encountered look clean.  Houses where takeout food boxes are strewn everywhere and lord only knows how long their contents have sat rotting.  A large percentage of the brewers who have helped me improve their fermentation quality live in places that are at this level of unkemptness or slightly above it.  The reason why the military drives cleaning home is partially due to public health, but it is to teach young service men and women to pay attention to detail.  Brewing consistent beer is about paying attention to detail, every little detail.

So...hoarders might not be able to make a clean starter. Seems reasonable. I doubt most homebrewers fit this description though. Hopefully my life will never depend on having to make a clean starter, but if it ever did, I think I’ll be ok.

[Saccharomyces]

One last thing, as I mentioned in an earlier post in this thread, the probability of two different scientists sequencing the same product and both coming to the conclusion that a yeast culture falls outside of the American family is close to nil unless they both sequenced a contaminant.  The dry yeast facilities do not only produce brewing yeast.  The also produce bread yeast.  The probability that there is cross contamination is higher than we would like to believe.  Let's think about it in peanut terms.  Plants that produce non-peanut-based food stuffs that also produce peanut-based food stuffs have to claim that they do.  The same thing happens with gluten.  While oats are naturally gluten-free, Quaker had to set up a separate facility for processing gluten-free oats because most of their oats are processed in plants that also process cereal grains that are not gluten-free.  If you have ever been in either White Labs propagation facility, you have seen that bacteria and wild yeast strains are propagated in a different building than the Saccharomyces strains.  The wild yeast and bacteria building is under negative pressure to keep those organism in where the the Saccharomyces building is under positive pressure to keep other organisms out.

The plate shown below was streaked from a culture I grew from the dregs of a bottle of Southern Tier bottle-conditioned pale ale.  We can assume that all of the well-isolated white dots on that plate are all the offspring is a single yeast cell; hence, the term single-cell pure culture or isolate.   What we do not know is if all of the well-isolated colonies are from a single strain of yeast.  The only way to know for certain is to transfer different colonies to different slants and use each slant to step-propagate a starter to use in brewing.  If the slants we create all produce the same fermentation characteristics, we know that we are dealing with a brewery that a) uses a single strain and b) has good biological quality control.  Now, the only way that the scientists who sequenced BRY-97 from the package could both come to the conclusion that the culture was not in the American family is if there were yeast colonies on the plate that were not BRY-97.  If Chris and Kristoffer are like me, they probably selected the largest well-isolated colony on the plate.  It could have been that the culture was infected with another yeast culture that grows faster and more robustly than BRY-97.  I have seen that occur in my own yeast travels.

[MDL]

Until I began pitching at Lallemand recommended rates I was very unhappy with the fermentation profile in terms of flavor. The final gravity was not an issue with lower pitch rates.

After many batches I have settled on a pitch rate of .85 grams/liter for Bry-97 and 1.7 grams/liter Diamond lager.

Pitched direct into fermentation vessel without aeration. 1.050 OG approx. I pitch while filling the fermenter at about 65 degrees. Lager gets cooled to 50F for fermentation.

[Saccharomyces]

You have a ton of speculation, anecdotes, and variability in your justification that dry strains aren’t what they are.

I am not sure how you have experienced a different performance in your wort inoculated with a different pitch rate of 34/70 than the mfr does in their standardized wort — which can be totally different composition that can easily produce different results (therefore comparing apples to oranges) — then jump to a completely a different strain’s analysis as proof of an assertion that dry strains aren’t what the mfr says they are.


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Did you to read the PDF that I linked from the source of W-34/70?  TUM states that W-34/70 (a.k.a. TUM 34/70) has an AA of 73%.  Even with a very fermentable wort, there is no way that a culture known to reliably produce an AA around 73% can reliably produce an AA of between 80 and 84% as stated on the Fermentis site, that is, unless it is contaminated or mutated.  TUM also states that W-34/70 is flocculant whereas W-34/78 is less flocculant.  What I am seeing is a lot of yeast that refuses to sediment (a.k.a. it is powdery), which is sign of non-flocculant yeast cells being in the culture at a significant level.  It does not mean that every package of W-34/70 that ships from Fermentis is this way.  It just means that people who are complaining about dry yeast still not being as reliable as liquid yeast have a case.  There are enough people still complaining about dry yeast cultures being hit or miss that there has to be some validity to their complaints.  Hopefully, this forum will remain a little more open minded about yeast than a very large forum where people who do not go along with group think are beaten down.  These people should be able to plead their case. We have to remember that I received a significant beating on this site when I introduced SNS.  Yet, I stood my ground (I will stand my ground on this one until I have enough evidence to rule out significant mutation or contamination). It was not until Denny tried the method and blogged about his experience that the beat-down stopped.  Now, SNS has become another tool in a brewer's toolbox.  Opportunity comes to those whose minds are prepared and still open to new knowledge.  I know from personal experience that maintaining that mindset becomes more difficult as we age.  I am as guilty as anyone else, but somehow, I keep making observations that go against what is being claimed.  On the liquid and cultured yeast side, I have yet to encounter a culture that does not live up to its data. However, I am certain that one will cross paths with me one day.
 

[Saccharomyces]

Until I began pitching at Lallemand recommended rates I was very unhappy with the fermentation profile in terms of flavor. The final gravity was not an issue with lower pitch rates.

After many batches I have settled on a pitch rate of .85 grams/liter for Bry-97 and 1.7 grams/liter Diamond lager.

Pitched direct into fermentation vessel without aeration. 1.050 OG approx. I pitch while filling the fermenter at about 65 degrees. Lager gets cooled to 50F for fermentation.

The problem with your thesis is that the same thing does not occur with liquid yeast.  Liquid yeast can be underpitched and not produce a product that wildly differs in flavor.  It may be little fruitier, but not what I am experiencing with W-34/70.  The difference between pitching 22 grams and 32 grams of yeast is in the noise.  It is not even a full replication period.  The yeast biomass does not grow linearly.  It grows exponentially at a rate of 2ⁿ, where n is the number of replication periods.  I wrote an entire blog entry about pitching rates being relative entitled "Yeast Cultures are Like Nuclear Weapons" (https://www.experimentalbrew.com/blogs/saccharomyces/yeast-cultures-are-nuclear-weapons). 

[BrewBama]

...  Even with a very fermentable wort, there is no way that a culture known to reliably produce an AA around 73% can reliably produce an AA of between 80 and 84% as stated on the Fermentis site, that is, unless it is contaminated or mutated.  ...

We disagree. A strain shouldn’t be expected to react the same as advertised if the conditions are different than the conditions the attenuation was based on. There are numerous variations that can create a complex account for the different performance.


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[RC]

You have a ton of speculation, anecdotes, and variability in your justification that dry strains aren’t what they are.

I am not sure how you have experienced a different performance in your wort inoculated with a different pitch rate of 34/70 than the mfr does in their standardized wort — which can be totally different composition that can easily produce different results (therefore comparing apples to oranges) — then jump to a completely a different strain’s analysis as proof of an assertion that dry strains aren’t what the mfr says they are.


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Hopefully, this forum will remain a little more open minded...Opportunity comes to those whose minds are prepared and still open to new knowledge.  I know from personal experience that maintaining that mindset becomes more difficult as we age.  I am as guilty as anyone else, but somehow, I keep making observations that go against what is being claimed.

Sidenote: Yeah I know the feeling. It's like when I claim that if your city uses chlorine gas to treat the water, you don't have to filter because all the chlorine will gas off when you heat the water. Woe is us!

[MDL]

I was never satisfied with lagers I attempted with liquid cultures. I assumed pitching rate was the cause. Never wanted to buy enough yeast or plan ahead to grow up enough.

I have no experience with 34/70 from Fermentis. However, overall I personally feel that I get better flavor results using Lallemand on the dry strains I have tried.

[ynotbrusum]

I am open to the points raised.  I remain dedicated to progress, yet I tend toward my own personal experience to reinforce an approach touted by others or criticized by others.  I tried SNS early on and found it to be working well and adopted it for starters.  I am open to an argument that production conditions for dry yeast do not reach sanitation in liquid yeast production levels.  I welcome this discussion without any prejudgment (nor lab skills and lab access).  Please continue....

[Saccharomyces]

Sidenote: Yeah I know the feeling. It's like when I claim that if your city uses chlorine gas to treat the water, you don't have to filter because all the chlorine will gas off when you heat the water. Woe is us!

Cities do not use chlorine gas to treat water.  They use sodium hypochlorite (NaOCl), which is basically common household bleach.  Sodium hypchlorite decomposes into hypochlorous acid and hypochloric acid when mixed with water.  While these compounds will completely off-gas given enough time at a given temperature. They will not completely off-gas in the time it takes to hit strike temperature; therefore, when mixed with malt, these compounds will react with malt, forming chlorophenols.  That is basic chemistry.  If that were not true, commercial breweries would not spend money on water filtration systems.  Another problem with brewing with straight, unfiltered municipal tap water that is treated with sodium hypochlorite is that the dosing often changes with the seasons, so the time to off-gas changes with the seasons. Water tends to more heavily dosed in the summer than the winter.  That is due to higher microflora counts in the summer than in the winter.  If you sit for the BJCP exam, you will become familiar with chlorophenols, more so if you start judging local contests.  A beer made with unfiltered, chlorinated tap water brew taken straight from the tap to kettle tastes very different than one made with filtered water from the same water source.

That being said, some cities dose what with a mixture of sodium hypochlorite and ammonia, more commonly known as chloramine.  No amount of boiling will remove that compound.

[Saccharomyces]

I am open to the points raised.  I remain dedicated to progress, yet I tend toward my own personal experience to reinforce an approach touted by others or criticized by others.  I tried SNS early on and found it to be working well and adopted it for starters.  I am open to an argument that production conditions for dry yeast do not reach sanitation in liquid yeast production levels.  I welcome this discussion without any prejudgment (nor lab skills and lab access).  Please continue....

I do not believe that the propagation of dry yeast in a bioreactor is problematic, but it may be.  We then have to deal with the fact that dry yeast has to first go through a fluidized bed dryer and then get packaged.  While things have improved from bad old days, it is clear that the process is not as foolproof as we have been led to believe.  I have remained silent on my dry yeast experiences since dry yeast became allegedly light years better than it used to be.  I chalked it up to I was used to brewing with cultured yeast that I propagated aseptically; therefore, I was more sensitive to yeast-derived off-flavors.  I am absolutely certain that people have had positive experiences with dry, but I am not blind to the fact that others who have been brewing for years with liquid cultures and/or cultured yeast have had trouble with dry yeast.  Yeast should be yeast.  In use, dry yeast should not perform any different that liquid cultures, but the evidence that it does is difficult to ignore.  Longer lags times are par for the course with dry yeast.  The peach ester that is common to US-05 is not common to any other Siebel BRY-96 descendant.  Why is that so?  Are the people who sense this ester crazy?  Or is the difference due to the fact people sense off-flavors at different thresholds. I suspect RC is blind to chlorophenols given his insistence that brewing with chlorinated water straight from the tap makes no difference in the outcome of a batch of beer.  On the other hand, I am so sensitive to phenolic compounds of any kind that I cannot drink Belgian beer or Hefeweizen. Cultures that are POF+ do not enter my brewery.  A place where I am blind is diacetyl.  I cannot sense that compound until it is at the almost in your face level.  We are talking about the full-on buttered popcorn or butterscotch level.  I know a BJCP judge who is like a bloodhound with respect to diacetyl.  He routinely astonishes me with his ability to sense it at low levels.

In the end, no one and do mean no one wants dry yeast to be the equal of cultured and liquid yeast more than me.  I have spent most of the time I have been brewing maintaining a yeast bank (that is why I know so much about yeast).  I was hoping this time around that I could focus on the beer instead of the microbiology of beer.  Trust me, maintaining a yeast bank is like having a second, unforgiving job.  To say that it is a lot of work is an understatement.  I am sure that Denny can attest to that reality. He was lucky enough to get Wyeast to propagate a Brewtek culture (CL-50) that he had kept alive for a long time.  I  plan to use Wyeast 1450 in an upcoming batch. The last time I used it was from a mini-slant of CL-50 in 1995.  It will be interesting to see how much the strain has remained stable over the years.

[RC]

While these compounds will completely off-gas given enough time at a given temperature. They will not completely off-gas in the time it takes to hit strike temperature.

Respectfully, you're simply wrong about this. Have you actually tried it and tested it? And yes, I know chemistry, you're not the only scientist on this forum. You bring a lot of great knowledge to this forum but you should consider taking your own advice: "Hopefully, this forum will remain a little more open minded...Opportunity comes to those whose minds are prepared and still open to new knowledge."

I suspect RC is blind to chlorophenols given his insistence that brewing with chlorinated water straight from the tap makes no difference in the outcome of a batch of beer.

Nope. I know exactly what it takes like. Come on man. Do you think you're the only one on this forum with good sensory skills? I'm sure yours are great, but there's no need to knock others' sensory skills. Your dogmatism is actually a bit insulting. It's unfortunate, because again, you have a lot of knowledge to share and I appreciate (most of) your posts. You remind me of that LODO guy...