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General Category => Yeast and Fermentation => Topic started by: Robert on October 18, 2018, 02:09:25 PM

Title: Dried yeasts and pH
Post by: Robert on October 18, 2018, 02:09:25 PM
I have been trying dried yeasts a fair bit of late, and have noticed something interesting.  The first generation fermentation finishes with an unusually low pH,  around 3.8, with (unless I'm deceiving myself and tasting what I expect to find) a predictable slight tartness in the beer.  On harvesting and repitching the yeast, subsequent generations seem to perform just like normal liquid cultures, with a finished pH of around 4.2.  Can anyone explain this?

Possible exceptions are W-34/70 and Windsor,  both quite powdery; but this may well be a red herring or just an outlier,  because I'm reporting only a nearer-normal first generation pH, having made no comparison with a repitch.
Title: Re: Dried yeasts and pH
Post by: BrewBama on October 18, 2018, 03:16:53 PM
I saw this and thought hmm, I’ve not noticed any tartness but I can check pH.

I just took a sample of an Alt fermented with 1st gen K-97 as I transferred to keg and would love to add a data point for you. ...but my pH meter seems to have gone South for the Winter.

Nothing to see here — except frustration. LOL


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Title: Re: Dried yeasts and pH
Post by: Iliff Ave Brewhouse on October 18, 2018, 03:49:00 PM
Very interested in this. I have a vienna lager with M84 that seems to exhibit this. Last night I had one and was thinking to myself, 'this is pretty good but I don't know what that tartness is'. I used the second generation on a Marzen so am curious to see if it's different.

I never cared for k97 because it was unusually tart to me but I never went past one generation. 
Title: Re: Dried yeasts and pH
Post by: denny on October 18, 2018, 03:51:18 PM
Rob, what yeasts have you noticed this with?  I quit using Nottingham many years ago because of tartness, but I didn't have a pH meter back then to check with.
Title: Re: Dried yeasts and pH
Post by: dmtaylor on October 18, 2018, 03:51:52 PM
I have been trying dried yeasts a fair bit of late, and have noticed something interesting.  The first generation fermentation finishes with an unusually low pH,  around 3.8, with (unless I'm deceiving myself and tasting what I expect to find) a predictable slight tartness in the beer.  On harvesting and repitching the yeast, subsequent generations seem to perform just like normal liquid cultures, with a finished pH of around 4.2.  Can anyone explain this?

Possible exceptions are W-34/70 and Windsor,  both quite powdery; but this may well be a red herring or just an outlier,  because I'm reporting only a nearer-normal first generation pH, having made no comparison with a repitch.

Excellent observation!!!!  I have been using mostly dried yeasts for several years now, and I have long noticed that they all seem to have the odd tartness.  I've always used fresh packs, not repitched.  I thought maybe I just didn't like dried yeast?  But if your observation is correct, then perhaps I should check pH, and perhaps we should all be making yeast starters for all dried yeasts!!!!!  Then it would always be "re-pitched", at least from the starter to the intended wort.

Fantastic.... why didn't we think of this before?!  Over the next few days I'll measure the pH of some of my finished beers, and see how they compare.  I've got several batches to choose from.  Easy enough to pull out the old pH meter (which yes, I do calibrate for EACH AND EVERY USE).

EDIT:  To answer Denny's question, I get a very peculiar tartness from WB-06 for certain.  Swore I'd never ever use that yeast again.  I still have a couple bottles of that one and will report back on exact pH reading.
Title: Re: Dried yeasts and pH
Post by: The Beerery on October 18, 2018, 04:09:15 PM
I get weird stuff from all dry yeasts, which is why I don't use them. I have noticed low pH, lemon, bleh.
Title: Re: Dried yeasts and pH
Post by: Robert on October 18, 2018, 05:11:47 PM
Denny, Nottingham and S-04 are definitely major culprits IME.  I have found  very low first gen pH and tartness) with those two,  but normal thereafter. I think other yeasts show it in varying degrees.

Dave, this is exactly where my train of thought is going -- a
decanted  starter/propagation could be just the thing!  I've never tried it but it would be a great experiment. The initial convenience of dried yeast over liquid as a new pitch would be lost.  But if dry yeast is your only viable source, as I know it is for many who don't have a reliable LHBS, then it's quite reasonable.  It would be better than having abnormal fermentation and flavor on every new pitch.   If you try it, please report.  (I just got a pitch of a particular liquid culture which I plan to run for a few batches, so it will be a while before I get the chance.)

I'm still curious -- especially knowing I'm not alone in this -- whether any microbiology experts could identify why this happens. 
Title: Re: Dried yeasts and pH
Post by: dmtaylor on October 19, 2018, 03:35:52 AM
WB-06 German hefeweizen is at pH 3.7.  It is too tart for my liking, not a horrible beer but zero clove or banana which is dumb.  It does have a slight chlorophenol, which is odd since I'm sure I used Campden, I always do, but that's the only phenol I get out of this.  Not my best hefeweizen, that's for sure.  But I remember being struck by the tartness the first time I ever tasted it, and today was no exception either.  Tart.  Can drink it, it's alright, but not a very good German hef.  So yeah, I won't be using WB-06 anymore.  But maybe for an American hefe, after second use and not fresh from a new pack of yeast, it might be okay!   ;)
Title: Re: Dried yeasts and pH
Post by: goose on October 19, 2018, 01:40:55 PM
This is an excellent topic!  I have never measured the pH of my finished beers but am going to start to do so.  At least it will give some data points that we can all look at.
For the record, I almost always used liquid yeasts.  I know starters tend to be a PITA, but I have always liked the results I have gotten from them.  In a pinch, I will sometimes use S-05 when I can't get to my LHBS before a brew day.  I will also keep track of tartness when I use them as I almost never re-pitch.  I just don't brew enough to make that a viable option.
Title: Re: Dried yeasts and pH
Post by: Robert on October 19, 2018, 02:41:03 PM
I love this forum.  Glad to know there's interest in pursuing this.  For further clarification of my methods and what I've so far compared:  Dry yeasts have all been direct pitched, no rehydration or aeration;  that's what Fermetis and MJ recommend, and Lallemand yeast seems to respond just the same.  Repitched yeast was treated as I would any repitch: slurry stored under beer, used within 5 days, aeration as usual.  I've not tried rehydration or a starter to see if that leads to a more normal fermentation and pH in the first generation.  And it would be nice to have corroboration of my observations about repitching vs. first generation.

At some early point the value of record keeping was impressed on me.  So from mashing in to packaging,  every time I pull a sample I record four parameters: time, temperature,  gravity and pH.   Asked why, I've said "just so I know things are going normally, or not."  Guess it's been worth it.
Title: Re: Dried yeasts and pH
Post by: joe_meadmaker on October 19, 2018, 08:32:55 PM
Like Goose, I also use liquid yeast almost exclusively.  So I don't have any personal experience to add to this discussion.  That said, I agree this is a fascinating topic.  It sparked a memory of a Brulosophy article on rehydrating dry yeast vs not.  It's here if anyone wants to check it out: http://brulosophy.com/2014/09/15/sprinkled-vs-rehydrated-dry-yeast-exbeeriment-results/ (http://brulosophy.com/2014/09/15/sprinkled-vs-rehydrated-dry-yeast-exbeeriment-results/)

I pulled it up and read through it again.  In the two batches Nottingham yeast is used.  In the discussion at the end, it is stated that the batch made with non-rehydrated yeast had a "subtle apple-like tartness".  Although it doesn't appear that this flavor was something most of the taste-testers were able to detect and/or identify.  Definitely interesting.
Title: Re: Dried yeasts and pH
Post by: Robert on October 19, 2018, 09:00:06 PM
 
Like Goose, I also use liquid yeast almost exclusively.  So I don't have any personal experience to add to this discussion.  That said, I agree this is a fascinating topic.  It sparked a memory of a Brulosophy article on rehydrating dry yeast vs not.  It's here if anyone wants to check it out: http://brulosophy.com/2014/09/15/sprinkled-vs-rehydrated-dry-yeast-exbeeriment-results/ (http://brulosophy.com/2014/09/15/sprinkled-vs-rehydrated-dry-yeast-exbeeriment-results/)

I pulled it up and read through it again.  In the two batches Nottingham yeast is used.  In the discussion at the end, it is stated that the batch made with non-rehydrated yeast had a "subtle apple-like tartness".  Although it doesn't appear that this flavor was something most of the taste-testers were able to detect and/or identify.  Definitely interesting.
I've always been exclusively liquid, real dry yeast noob, maybe that's why this jumped out at me.  Hundreds of batches behaving similarly, and then suddenly an unexpected effect. Too bad Marshall didn't record pH data.  But the tasting data is interesting.
Title: Re: Dried yeasts and pH
Post by: Robert on October 20, 2018, 12:55:05 AM
Some ignorant musings of an amateur, trying to work through stuff a bit over my head.

I know most of the pH reduction occurs very early on, and this is crucial to a healthy fermentation.   The majority of organic acid production, as I understand  it, occurs during the anaerobic repressed fermentation phase.  Could dried yeast,  by bypassing the earlier aerobic (I said aerobic,  not respiratory,  so don't go all Crabtree on me) phase  and proceeding straight to anaerobic metabolism, have more opportunity for acid production?   In which case the making of a starter, run to completion and decanted,  might just do the trick?   I wonder if some part of the excess acidification might be a stress response (shock excretion,) which might be alleviated by rehydration.   But a starter would address either mechanism.   Help with this welcome.   Anyway.  Enough of the books for this evening,  time for a practical assessment of the end product.
Title: Dried yeasts and pH
Post by: BrewBama on October 20, 2018, 02:09:24 AM
Robert, have you cleaned your kegs with the milkstone remover?  If so, did you rinse really well afterwards? Just reaching for straws here.


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Title: Re: Dried yeasts and pH
Post by: Robert on October 20, 2018, 02:44:20 AM
Oh, it's absolutely not equipment related.   Good thought though!  (One might suspect you'd had a career involving troubleshooting systems... oh you did.  Thanks for your service.)  As noted, I keep good records.  I know what a normal fermentation record looks like,  and what's interesting is that the same yeast, in the same conditions,  behaves differently in first and subsequent generations.   Which, with respect to this parameter, does not occur with liquid cultures,  IME.  I have a fairly small number of data points, but enough to establish a clear pattern, raise a red flag, and suggest a hypothesis, or I wouldn't have started this thread; I haven't found a confirmed exception.  Before I decided to explore for myself the possible advantages of dry yeast,  I'd noticed plenty of mentions on the forum of tartness with dry yeast.   I realized that my habit of monitoring pH, and reusing yeast, might have peeled back  a layer others hadn't noticed.  What I lack is the ability  to identify a likely mechanism, and remedy.  Forgive me if I'm rambling.  The practical assessment of product is going well.
Title: Re: Dried yeasts and pH
Post by: Robert on October 24, 2018, 12:33:16 AM
Sampled another 2d gen today.  Nottingham.   1st gen finished at pH 3.78, 2d gen 4.2, with no tartness,  nice balanced flavor.
Title: Re: Dried yeasts and pH
Post by: Joe Sr. on October 24, 2018, 02:59:44 AM
Like Denny, I gave up on Nottingham ages ago due to the tartness. I don't recall tartness with other dry yeasts but I have no reason to doubt your experience. I could check my notes from back in the day. Haven't used dry yeast in a long time.


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Title: Re: Dried yeasts and pH
Post by: ynotbrusum on October 24, 2018, 11:13:52 AM
Great discussion.  I use a fair amount of dried lager yeast and routinely rehydrate, as it seems to cut the lag time I otherwise experience with dried yeast.  I also repitch on a regular basis.

I happened to use first gen Nottingham in a dry stout batch that is now ready to keg, so I will sample for tartness - I rehydrated it, FWIW...
Title: Re: Dried yeasts and pH
Post by: Joe Sr. on October 24, 2018, 03:52:23 PM
Great discussion.  I use a fair amount of dried lager yeast and routinely rehydrate, as it seems to cut the lag time I otherwise experience with dried yeast.  I also repitch on a regular basis.

I happened to use first gen Nottingham in a dry stout batch that is now ready to keg, so I will sample for tartness - I rehydrated it, FWIW...

I've always rehydrated dry yeast and it did not seem to have an impact on the tartness.

I'm pretty sure I've repitched Notty in the past, but have no specific recollection of the tartness being there or not on a second gen.

I used to use dry yeast, and in particular Notty, pretty regularly.  It got to the point where I was noticing the tartness so much I had to go back and check my notes on beeers and the yeast was the common thread on each.  I was afraid I had some sort of infection, but nope, just Nottingham.

I do not own a pH meter, so that's something I have never checked. 
Title: Re: Dried yeasts and pH
Post by: hulio555 on October 24, 2018, 04:24:05 PM
I have been trying dried yeasts a fair bit of late, and have noticed something interesting.  The first generation fermentation finishes with an unusually low pH,  around 3.8, with (unless I'm deceiving myself and tasting what I expect to find) a predictable slight tartness in the beer.  On harvesting and repitching the yeast, subsequent generations seem to perform just like normal liquid cultures, with a finished pH of around 4.2.  Can anyone explain this?

Possible exceptions are W-34/70 and Windsor,  both quite powdery; but this may well be a red herring or just an outlier,  because I'm reporting only a nearer-normal first generation pH, having made no comparison with a repitch.
The problem with dry yeast is it is contaminated with non-yeast microbes, if yeast grows faster than bacteria (lactos) there would be more of it in future generations. leaning out the effect of lower pH caused by the smaller % of lactic acid producing microbes. one possible reason.
Title: Re: Dried yeasts and pH
Post by: BrewBama on October 24, 2018, 04:45:27 PM
The problem with dry yeast is it is contaminated with non-yeast microbes, if yeast grows faster than bacteria (lactos) there would be more of it in future generations. leaning out the effect of lower pH caused by the smaller % of lactic acid producing microbes. one possible reason.

Sounds plausible.


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Title: Re: Dried yeasts and pH
Post by: Robert on October 24, 2018, 05:32:03 PM
The problem with dry yeast is it is contaminated with non-yeast microbes, if yeast grows faster than bacteria (lactos) there would be more of it in future generations. leaning out the effect of lower pH caused by the smaller % of lactic acid producing microbes. one possible reason.
So if this hypothesis is correct,  rehydration should result in the same 1st generation pH as direct pitching,  but making a starter might make a difference.  Experiment needed.
Title: Re: Dried yeasts and pH
Post by: dmtaylor on October 25, 2018, 02:05:57 AM
The problem with dry yeast is it is contaminated with non-yeast microbes, if yeast grows faster than bacteria (lactos) there would be more of it in future generations. leaning out the effect of lower pH caused by the smaller % of lactic acid producing microbes. one possible reason.
So if this hypothesis is correct,  rehydration should result in the same 1st generation pH as direct pitching,  but making a starter might make a difference.  Experiment needed.

Or here's an easy one.  Campden kills bacteria, right?  So, just before pitching, add some Campden.  Pitch as normal.  The microbes should die but the yeast should survive -- some of the yeast anyway -- cultured yeast is much more robust than wild beasts.  Then ferment out as normal and check pH, yadda yadda.
Title: Re: Dried yeasts and pH
Post by: goose on October 25, 2018, 01:41:57 PM
Some ignorant musings of an amateur, trying to work through stuff a bit over my head.

I know most of the pH reduction occurs very early on, and this is crucial to a healthy fermentation.   The majority of organic acid production, as I understand  it, occurs during the anaerobic repressed fermentation phase.  Could dried yeast,  by bypassing the earlier aerobic (I said aerobic,  not respiratory,  so don't go all Crabtree on me) phase  and proceeding straight to anaerobic metabolism, have more opportunity for acid production?   In which case the making of a starter, run to completion and decanted,  might just do the trick?   I wonder if some part of the excess acidification might be a stress response (shock excretion,) which might be alleviated by rehydration.   But a starter would address either mechanism.   Help with this welcome.   Anyway.  Enough of the books for this evening,  time for a practical assessment of the end product.

Another observation based on Rob's post here.  When i used dry yeast, I always pitched directly into the wort as recommended by Fermentis and always had relatively short lag times.  One of the locals here (who I brew with a lot) said that he always re-hydrated his dry yeast to reduce the number of dead cells in the pitch caused by shocking the yeast in a high sugar environment.  I tried it the very last time I used US-05 (had to because I could not get 1056 before my brew day) and had a lag time that way too long.  I had to do the hubba bubba to get a couple more packages and re-pitch (did not re-hydrate them) to get the beer started.  Obviously, this was the very last time I used dry yeast.
This may have been operator error here.  I did make sure that I cooled the re-hydrated yeast in a covered glass measuring cup to within about 7 degrees of the cooled wort temperature to avoid thermally shocking the yeast.  Never did figure out what happened, so I have chalked it up to operator error.

This has been an excellent discussion topic and has led me to record more data points on my beers as they are fermenting!
Title: Re: Dried yeasts and pH
Post by: ynotbrusum on October 25, 2018, 08:35:32 PM
When I rehydrate, I usually do so in my fermentation chest, so it is chilled and being pitched into the same or warmer wort once I pitch....again these are lagers, but I do the same for some ales that I start on the colder side for initial fermentation.
Title: Re: Dried yeasts and pH
Post by: BrewBama on October 25, 2018, 09:50:17 PM
If you choose to use 2nd gen dry yeast, yet only brew once a month or so, how do you properly store your yeast for that long without fear of it degrading?


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Title: Re: Dried yeasts and pH
Post by: Joe Sr. on October 25, 2018, 10:01:17 PM
If you choose to use 2nd gen dry yeast, yet only brew once a month or so, how do you properly store your yeast for that long without fear of it degrading?


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Not specific to 2nd gen dry yeast, but I keep slurry in rubbermaid containers in my beer fridge.  When I want to brew, I take out the slurry and build a starter.  90% of the time the starters are good.  Occassionally, I toss one.  If the slurry sits too long, I toss it and start fresh.
Title: Dried yeasts and pH
Post by: BrewBama on October 25, 2018, 10:32:55 PM
Thanks Joe Sr. How long is ‘too long’? 

Edit: I’ve read “If less than two weeks, brewers will usually have no problem reusing yeast. Over two weeks and you may or may not have problems. After four weeks, the viability of yeast slurry is usually 50% or lower. As yeast sit in storage, they consume their glycogen reserves.”

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Title: Re: Dried yeasts and pH
Post by: Robert on October 25, 2018, 11:20:24 PM
I'm not Joe, but... First the disclosure,  I can't remember the last time I reused any yeast more than 5 days after harvesting,  but I know I used to do it with no problem.   We homebrewers have a distinct advantage over the pros. A little yeast in a temperature controlled, 5-10 gal fermenter is not subject to the same hydrostatic pressure and heat buildup as in the cone of big fermenter,  so it can be much healthier at harvest than advice based in commercial practice might suggest,  and likewise will store better in a small jar in the fridge than in the cone or a brink.   Most yeasts should be good to just directly repitch at least two weeks out.  Just pitch a little more than you normally would to make up for non viable yeast and non yeast material.   If you're at all concerned,  make a starter.  And remember the best medium for storage is the beer the yeast fermented.  Don't rinse,  that raises the pH making it more vulnerable to bacteria,  and introduces oxygen which may accelerate glycogen depletion.   (Come to think of it, back in the day I did rinse, and let it sit for weeks, and it was still good.  But don't do that.) 
Title: Re: Dried yeasts and pH
Post by: hulio555 on October 25, 2018, 11:23:20 PM
The problem with dry yeast is it is contaminated with non-yeast microbes, if yeast grows faster than bacteria (lactos) there would be more of it in future generations. leaning out the effect of lower pH caused by the smaller % of lactic acid producing microbes. one possible reason.
So if this hypothesis is correct,  rehydration should result in the same 1st generation pH as direct pitching,  but making a starter might make a difference.  Experiment needed.
which may be why every dry yeast manufacturer suggests that we rehydrate and every advanced brewer suggest an appropriate starter size
Title: Re: Dried yeasts and pH
Post by: Joe Sr. on October 26, 2018, 04:47:39 PM
Thanks Joe Sr. How long is ‘too long’? 

Edit: I’ve read “If less than two weeks, brewers will usually have no problem reusing yeast. Over two weeks and you may or may not have problems. After four weeks, the viability of yeast slurry is usually 50% or lower. As yeast sit in storage, they consume their glycogen reserves.”

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In all honesty, I've reused yeast stored for up to a year.  I pour the yeast from the fermenter into a sanitized container, seal it up, and put it in the fridge.  I prefer Rubbermaid type containers because they will bulge and not explode if pressure builds up.  I just kegged an O-fest that I made with last years yeast.  I was worried about the slurry, but it took off in the starter and the beer tasted great going into the fermenter.

The 5 days to two weeks "rule" is more geared towards repitching the slurry rather than growing up a starter.  At least IMO and experience.
Title: Re: Dried yeasts and pH
Post by: Robert on November 02, 2018, 01:48:20 AM
The problem with dry yeast is it is contaminated with non-yeast microbes, if yeast grows faster than bacteria (lactos) there would be more of it in future generations. leaning out the effect of lower pH caused by the smaller % of lactic acid producing microbes. one possible reason.
So if this hypothesis is correct,  rehydration should result in the same 1st generation pH as direct pitching,  but making a starter might make a difference.  Experiment needed.
Not brewing this weekend but next.  Nottingham would be a reasonable choice for the planned brew,  for which I want good attenuation.  I will make a decanted starter this time, and report fermentation data here.
Title: Re: Dried yeasts and pH
Post by: Robert on November 03, 2018, 06:08:05 PM
It seems that this topic been brought to the attention of Fermentis.  They reached out to me yesterday, and I've exchanged some emails, covering several issues.   

They dispute the "contamination" idea, based on the assertion that no brewing yeast,  liquid or dry, is 100% pure, nor does it need to be for brewing purposes.  Further they suggest that in triangle tests, panels cannot distinguish beers fermented with liquid or dry yeast,  but when informed that a beer is from dry yeast, will then claim to detect tartness.  All very interesting (and as I said I may be deluding myself as to the taste because I've seen the pH readings) but of course, valid or not, that's all off topic,  as what I'm curious  about is the actual measured pH value.

What is very interesting is this:

They provided an EBC paper (1997) reporting comparisons of dried yeast and second generation brewery yeast,  both prepared from the same lab culture of a lager strain, using pilot scale fermentation.   They found that rehydration vs direct pitching of dried  yeast made no significant difference in fermentation performance,  including cell count during fermentation.  There was no significant difference  between the liquid and dried yeasts in fermentation performance. They also found no significant analytic difference between the beers made with the liquid and dried yeasts,  including finished beer pH,  and tasting panels could not distinguish them.   This is a scanned image,  not a web page,  but here's a link to it on my Google Drive if anyone's interested.  https://drive.google.com/file/d/1zh2KW1pgHP-KM6CU5sxEOukTHm7uFdNM/view?usp=drivesdk

Now, this experiment involved a lager yeast.  I mentioned above in the thread that I have only one example of a dried yeast lager fermentation to offer,  and no comparison with a repitch,  but that my dried  yeast fermentation was seemingly consistent with my experience with liquid cultures of the same original strain (W-34/70.)   So also consistent with the results in the paper.   Where I have seen the low pH with first generation dried yeast is in ales, specifically Nottingham and S-04.  So it would still be interesting if the community could provide more data.  If you repitch, do you see a measured pH difference in subsequent fermentations, with either liquid or dried yeasts?  If you don't repitch, do you see such a difference between liquid and dried yeasts on a group average?  Does rehydration matter?  We may be able to do one of two things:  Either show that there is something happening that needs an explanation,  or that my observations are statistically insignificant or unreproducable.   Either would be interesting.   

(Whether I am able to do a starter with dried yeast this week will depend on my schedule.   I may direct pitch again on brew day,  either Nottingham or S-04.   Either way, it will be another data point. )
Title: Re: Dried yeasts and pH
Post by: BrewBama on November 03, 2018, 07:06:56 PM
Interesting that they reached out to you. I sent them an email mid Oct to ask about the issue. I did tell them there is an ongoing topic on the AHA forum. Glad they took an interest and investigated. I rely on dry yeast and if a solution can be determined I need to know how to make my best beer with it. If it’s as simple as making a starter, decant and pitch I can do that.


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Title: Re: Dried yeasts and pH
Post by: Robert on November 03, 2018, 07:30:33 PM
They said someone had emailed, leading them to read the thread.  Guess that was you, thanks for getting their attention,  BrewBama.  I did tell the representative I'd try to keep the topic alive on here and get more data.  Biggest surprise for me in all this is how few people track fermentation data.  I want to rely on dried yeast myself, as it removes the problem of diminishing viability in storage,  and is dead easy to use.  Ultimately if we find there are pH anomalies,  do they actually correspond to taste defects?   Only triangle tests would tell, and Fermentis (of course) are quite certain they know what the answer would be. 
Title: Re: Dried yeasts and pH
Post by: BrewBama on November 03, 2018, 07:52:02 PM
I just put a replacement pH meter (MW101) on order so I should be able to provide additional data soon. I just never thought to test pH of a finished beer.


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Title: Re: Dried yeasts and pH
Post by: Joe Sr. on November 05, 2018, 03:54:49 PM
Further they suggest that in triangle tests, panels cannot distinguish beers fermented with liquid or dry yeast,  but when informed that a beer is from dry yeast, will then claim to detect tartness.  All very interesting (and as I said I may be deluding myself as to the taste because I've seen the pH readings) but of course, valid or not, that's all off topic,  as what I'm curious  about is the actual measured pH value.

The only reason I know that Nottingham tastes tart is because when I've detected tartness I've gone back to check my records.  So, my single data point is that I noticed the flavor before I knew the yeast.

I'm no help on the pH, though.
Title: Re: Dried yeasts and pH
Post by: denny on November 05, 2018, 04:36:21 PM
Further they suggest that in triangle tests, panels cannot distinguish beers fermented with liquid or dry yeast,  but when informed that a beer is from dry yeast, will then claim to detect tartness.  All very interesting (and as I said I may be deluding myself as to the taste because I've seen the pH readings) but of course, valid or not, that's all off topic,  as what I'm curious  about is the actual measured pH value.

The only reason I know that Nottingham tastes tart is because when I've detected tartness I've gone back to check my records.  So, my single data point is that I noticed the flavor before I knew the yeast.

I'm no help on the pH, though.

I quit using Nottinghamk maybe 15 years ago because of the tartness I detected.  No confirmation bias there.
Title: Re: Dried yeasts and pH
Post by: jeffy on November 05, 2018, 04:37:37 PM
Further they suggest that in triangle tests, panels cannot distinguish beers fermented with liquid or dry yeast,  but when informed that a beer is from dry yeast, will then claim to detect tartness.  All very interesting (and as I said I may be deluding myself as to the taste because I've seen the pH readings) but of course, valid or not, that's all off topic,  as what I'm curious  about is the actual measured pH value.

The only reason I know that Nottingham tastes tart is because when I've detected tartness I've gone back to check my records.  So, my single data point is that I noticed the flavor before I knew the yeast.

I'm no help on the pH, though.

I quit using Nottinghamk maybe 15 years ago because of the tartness I detected.  No confirmation bias there.
Me too.  I always thought of that yeast as if it were the generic package they always gave you in a basic beginner kit beer.
Title: Re: Dried yeasts and pH
Post by: Robert on November 05, 2018, 07:02:42 PM
I tapped my direct pitched Nottingham batch this weekend.   It is definitely tart.  Bah!  I'll probably drink it, but I'll grumble and gripe every time I do.  This one read pH 3.8 post fermentation,  but now I can absolutely say it's not confirmation bias in my case either.  Hope the repitch, pH 4.2, lacks the tartness.  Or I'll have to wait till the batch after that for something decent to drink.   So no Notty for now.  It's either a starter with S-04 or just repitch last week's WY1318 next weekend.  I'd like something more attenuative than 1318, so maybe the S-04.  But it's my Christmas beer, so I'm not keen on taking chances....  Beer is supposed to make me happy!


EDIT Not taking chances.  Stopped by LHBS for a nice, fresh WLP007.  Which I originally had in mind.   So the starter from S-04 experiment will have to wait a bit longer.   Though allegedly these are originally the same strain,  so comparison of a couple of generations of each would be interesting.
Title: Re: Dried yeasts and pH
Post by: Joe Sr. on November 05, 2018, 07:04:56 PM
Yes.  I expected you would get tartness.  I think there are enough varied reports of tartness to confirm it is actually there.

Good luck with the repitch.  Please let us know how it turns out.
Title: Re: Dried yeasts and pH
Post by: ynotbrusum on November 05, 2018, 07:19:07 PM
I just kegged a dry stout fermented with Notty, where a slight tartness may be a good thing.  I will be checking on it soon and will report back on this, too, for another data point.  FWIW, it was a 10 gallon batch that I split into two fermenters - one was rehydrates and one was just sprinkled on the wort.  Both were whipped with a wine degasser, IIRC.

I will have to take pH measurements on the finished beer, but I didn’t take measurement of pH anywhere along the way pre-fermentation.
Title: Re: Dried yeasts and pH
Post by: Chino Brews on November 07, 2018, 02:42:48 AM
For the record, Fermentis recommends you direct pitch all of their brewing strains of active dry yeast under their Easy2Use campaign. They just completed a multi-year study and showed that direct pitchyng had equal or better performance than rehydrating under every pitching temp in a wide range and in every starting gravity within a very wide range. The direct pitched yeast performed better in terms of attenuation, abv tolerance, and ester production.

One of the technical reps at Fermentis was kind enough at Homebrew Con 2018 in Portland to fire up his laptop and spend 45 minutes going through proprietary data with me. I can't remember if beer pH was one of those highlighted metrics (being Homebrew Con, I had had a few).

I was a devout rehydrater and active proselytizer for rehydration. I have undergone a complete conversion and now I direct sprinkle my active dry yeast.
Title: Re: Dried yeasts and pH
Post by: BrewBama on November 07, 2018, 03:56:45 PM
I tapped my direct pitched Nottingham batch this weekend.   It is definitely tart.  Bah!  I'll probably drink it, but I'll grumble and gripe every time I do.  This one read pH 3.8 post fermentation,  but now I can absolutely say it's not confirmation bias in my case either.  Hope the repitch, pH 4.2, lacks the tartness.  Or I'll have to wait till the batch after that for something decent to drink.   So no Notty for now.  It's either a starter with S-04 or just repitch last week's WY1318 next weekend.  I'd like something more attenuative than 1318, so maybe the S-04.  But it's my Christmas beer, so I'm not keen on taking chances....  Beer is supposed to make me happy!


EDIT Not taking chances.  Stopped by LHBS for a nice, fresh WLP007.  Which I originally had in mind.   So the starter from S-04 experiment will have to wait a bit longer.   Though allegedly these are originally the same strain,  so comparison of a couple of generations of each would be interesting.

Add a pinch of baking soda to raise the pH/reduce tartness?


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Title: Re: Dried yeasts and pH
Post by: dmtaylor on November 07, 2018, 04:15:32 PM
Add a pinch of baking soda to raise the pH/reduce tartness?

I'm actually considering the same thing.  Next time I encounter an odd tartness prior to packaging, add baking soda to bring pH up a bit.  And can experiment in the glass with just a tiny pinch of like 1/64 teaspoon or whatever (and yes I actually have spoons to measure this).
Title: Dried yeasts and pH
Post by: BrewBama on November 08, 2018, 12:58:44 PM
I just took a sample from my finished but not yet carbonated Dunkel. I used two packs of MJ84 to inoculate. I did make a starter, cold crashed, and decanted.  The pH is 4.23.


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Title: Re: Dried yeasts and pH
Post by: Robert on November 09, 2018, 02:52:22 AM
I just took a sample from my finished but not yet carbonated Dunkel. I used two packs of MJ84 to inoculate. I did make a starter, cold crashed, and decanted.  The pH is 4.23.


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So one example of a dry yeast and a decanted starter yielding normal pH.  And for reference,  that is how I've taken all my finished beer pH readings, before carbonation.   If already carbonated,  the sample should be degassed so we have consistent data.
Title: Re: Dried yeasts and pH
Post by: goose on November 09, 2018, 02:25:44 PM
I just took a sample from my finished but not yet carbonated Dunkel. I used two packs of MJ84 to inoculate. I did make a starter, cold crashed, and decanted.  The pH is 4.23.


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So one example of a dry yeast and a decanted starter yielding normal pH.  And for reference,  that is how I've taken all my finished beer pH readings, before carbonation.   If already carbonated,  the sample should be degassed so we have consistent data.

And, carbonated beer will be a bit more acidic.  Dissolving CO2 in water or beer creates carbonic acid which lowers the pH.  So degassing or measuring before carbonating will give you a more reliable reading .
Title: Re: Dried yeasts and pH
Post by: klickitat jim on November 09, 2018, 09:07:17 PM
I use 20ml sample cups.... condiment cups... for all things ph. I found that by the time a 20 ml sample reaches room temp it's not fizzing anymore. The idea is to measure the same every time.
Title: Re: Dried yeasts and pH
Post by: ynotbrusum on November 10, 2018, 09:52:56 PM
So on a dry stout with non-rehydrated yeast (i.e., sprinkled onto the wort), the pH measured right at 4.30, so not so acidic, I should think.  But I do get some tartness that belies the relatively neutral pH reading.  Is it just in my head?  I don’t THINK so, but who knows...
Title: Dried yeasts and pH
Post by: BrewBama on November 10, 2018, 10:26:45 PM
I just checked a TX Brown Ale I have on tap. I used S-04 sprinkled atop the wort. I let it go flat and come up to room temp before checking. It’s pH is 4.34 and I do not detect tartness though I wish it had a bit more hop bitterness.

EDT: I corrected the yeast. I used -04 in this beer vs Notti which makes more sense because I’ve read -04 mutes hops. I believe it.

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Title: Re: Dried yeasts and pH
Post by: Robert on November 10, 2018, 10:55:44 PM
Well, now I'm starting to really wonder why I was so consistently getting those low 1st generation pH levels,  if others haven't,  with the same yeast.  May be more complicated than just wet/dry, 1st generation/ repitch.  I'll have to eventually see if I can replicate the results myself.   As far as I know the form of yeast was the only variable,  my procedure otherwise identical.   Hope more data follow.  BTW I took a sample of the repitched Nottingham batch when I put it on gas to carbonate the other day,  batch that finished at 4.2 when 1st generation was 3.8 and is rather tart;  this batch shows no tartness.   That's some good news.
Title: Dried yeasts and pH
Post by: BrewBama on November 11, 2018, 07:15:07 PM
Not sure what to say. I just checked an Amer Amber Ale fermented with 1st gen Nottingham. Again, let it go flat and get to room temp.  The pH is 4.46.

(This is the correct Notti beer)

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Title: Re: Dried yeasts and pH
Post by: Robert on November 11, 2018, 07:32:10 PM
Well, I asked the question here because I saw something I couldn't explain.   I had four instances of dry yeast (S-04 and Nottingham) direct pitched resulting in low pH levels like I'd never seen before, but only in the first generation,  each of those pitches taken out a couple more generations behaved normally.  In amongst these, W-34/70 and Windsor did not show this phenomenon.  Never seen it with liquid cultures.  Maybe I never will be able to explain it.  It will be interesting to see if it happens again whenever I next use dry yeast.  Being something of a dry yeast noob even after decades of brewing, it really concerned me.   But it doesn't seem to be a general problem with dried yeast. I'm keeping the S-04 in the fridge as an emergency backup.

(The only one of these I'd previously used was W-34/70 years ago, and I made starters, just to compare it with the liquid versions. That would be another topic.)
Title: Re: Dried yeasts and pH
Post by: BrewBama on November 11, 2018, 08:33:25 PM
Which is why I shot a note to one of the mfr. I don’t have a reliable source for liquid yeast so dry yeast has to work for me. I thought my pH would be inline with your findings and my taste buds were the anomaly.


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Title: Re: Dried yeasts and pH
Post by: Northern_Brewer on November 14, 2018, 10:32:28 PM
Here's another take on it - national tastes vary, as do serving methods, and British yeasts make the "correct" amount of acid for cask beer, the problem is not the yeast but US brewers taking it over the top by adding too much carbonic acid in keg.  ;)

If you look at Murphy & Sons, one of the main tech support labs for the Burton breweries, they recommend (https://www.murphyandson.co.uk/resources/technical-articles/ph-of-beer/) a final pH of 3.7-4.1 which is several points lower than a US brewer would think was normal. Some of that is down to serving in cask, which means less carbonic acid and a greater need for anti-bacterial acidity, but it points to differences in tastes as well I feel.

S-04 over 68F seems to produce acid regardless though, I'd put that in a special case (and I half wonder if it hasn't got a souped-up lactate metabolism through exposure to milk stouts at some point in its career).
Title: Re: Dried yeasts and pH
Post by: Robert on November 24, 2018, 01:02:10 AM
The batch with the repitched Nottingham finished with a normal pH and indeed has none of the tartness of the dry yeast batch.   If I had to complain about the fermentation character it would be that it's too neutral and clean.  So still don't know what's going on but my results are still consistent.   Maybe I'll come back to dry yeast at some point.  Till then a mystery.  Glad it's working for those who depend on it.
Title: Re: Dried yeasts and pH
Post by: BrewBama on November 25, 2018, 02:04:34 PM
That’s why I like Nottingham — it’s ability to get out of the way. 


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Title: Re: Dried yeasts and pH
Post by: Robert on November 25, 2018, 02:16:58 PM
That’s why I like Nottingham — it’s ability to get out of the way. 


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And exactly why I chose it, this was my first batch trying the Chevallier malt and I wanted nothing obscuring it.  Glad it worked out as it did this time.
Title: Re: Dried yeasts and pH
Post by: mabrungard on November 25, 2018, 02:59:52 PM
NB, that is interesting insight into S-04 yeast. I’ve used it a couple of times and found it to be very bready when young, but it became quite tart with increasing age.
Title: Re: Dried yeasts and pH
Post by: denny on November 25, 2018, 03:49:18 PM
NB, that is interesting insight into S-04 yeast. I’ve used it a couple of times and found it to be very bready when young, but it became quite tart with increasing age.

Exactly my experience, too.
Title: Re: Dried yeasts and pH
Post by: BrewBama on November 25, 2018, 08:01:03 PM
That is so interesting: I don’t find S-04 to be tart at all. I find it ferments very quickly and leaves a crystal clear, clean sweetness in the beer.

However, I normally finish a keg in about four weeks so ‘age’ is really not in my repertoire.


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Title: Re: Dried yeasts and pH
Post by: Robert on November 26, 2018, 03:52:25 AM
And can experiment in the glass with just a tiny pinch of like 1/64 teaspoon or whatever (and yes I actually have spoons to measure this).
And I have spoons designated as "tad, dash, pinch, and smidgen," in descending order.   As if Granny's hand could be standardized.
Title: Re: Dried yeasts and pH
Post by: mainebrewer on November 26, 2018, 11:36:27 AM
And can experiment in the glass with just a tiny pinch of like 1/64 teaspoon or whatever (and yes I actually have spoons to measure this).
And I have spoons designated as "tad, dash, pinch, and smidgen," in descending order.   As if Granny's hand could be standardized.

And I thought that I was the only one with measuring spoons like that!  :) 
Title: Re: Dried yeasts and pH
Post by: Robert on December 19, 2018, 04:11:29 PM
Well, I just kegged a batch fermented with S-04 direct pitched.   Finished pH 4.11, perfectly normal.  So I can't be sure why I had such consistently low pH in direct pitch batches for such a run, but: 

The one thing different about this batch was that I was careful to acidify the wort at 10 minutes in the kettle to pH 5.0, rather than leave it where it landed on its own, a bit higher.  I was maybe lazy about this over the summer.   Not sure if that had an effect, but I have seen this with lagers (with liquid cultures,)  that a lower pH in pitching wort does not lead to the intuitively expected lower beer pH.   I know Prof Narziß has written about this in connection with acid malt and other methods of biological acidification,  maybe someone has an insight.  Still doesn't explain the different results I saw in subsequent generations.

As for me, I'm happy to have a dry ale yeast I quite like that now seems well behaved.  There won't be a repitch for comparison this time;  direct pitching a fresh sachet is just too cheap and easy.   What I was after in the first place.  Now if I can find a dry lager yeast I like just as much....

Title: Dried yeasts and pH
Post by: BrewBama on December 19, 2018, 07:58:01 PM
I’ve never adjust kettle pH at 10 min. <<I’ve been lazy for years!>> LOL

I am still very curious with the reason behind the low pH you experienced.  I find it interesting the company man didn’t engage further.  Seems like they’d want to know, too.

One thing I didn’t ask: do you condition your malt prior to milling?  Do you mill the day/night (or more) prior to brewing?

FWIW, I like S-189, W-34/70, M54 and M84. I’ve yet to try M76, S-23, or Diamond.

I also like S-04 for Ale because it is fast and floccs very well. The lower attenuation has to be planned for though.


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Title: Re: Dried yeasts and pH
Post by: Robert on December 19, 2018, 08:46:25 PM
I’ve never adjust kettle pH at 10 min. <<I’ve been lazy for years!>> LOL

I am still very curious with the reason behind the low pH you experienced.  I find it interesting the company man didn’t engage further.  Seems like they’d want to know, too.

One thing I didn’t ask: do you condition your malt prior to milling?  Do you mill the day/night (or more) prior to brewing?

FWIW, I like S-189, W-34/70, M54 and M84. I’ve yet to try M76, S-23, or Diamond.

I also like S-04 for Ale because it is fast and floccs very well. The lower attenuation has to be planned for though.


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I don't condition, and usually mill the night before.

I don't always (don't often?) adjust kettle pH either, but I'm thinking this could have had an effect thusly:  If, as someone earlier in the thread hypothesized, the low pH resulted from (within normal tolerance)  bacterial contamination of the dry yeast, while the normal performance on repitching was because the yeast had outstripped the bacteria in the first generation, then the lower pH at pitching could have suppressed the bacteria in this most recent batch.   I'll have to check the technical information on the Fermentis site  to see if they mention an optimal pH for pitching wort.  And why did I have this problem and you didn't?   So many other variables, we'll never know what the key difference in our process is.

As to lager yeast,  thanks for the recommendations.   I've become disenchanted with 34/70 in all its forms, even though it was my house yeast through most of my 8-year lager mania.  The others I can get locally are S-23 and S-189, and maybe Diamond, not sure about that one.  Never used any MJ's, but will try anything.   

I really do like S-04 not just because it's quick and clears well, but I also like the flavor, and the attenuation is about what I expect of an English ale yeast. This weekend I'm going to direct pitch it again, and I'll report whether I get a repeat of this success.