Any low oxygen brewers out there use dry yeast?
Do you get good results?
How do you pitch it?
Then there's the problem of removing sulfites. If you don't get them out, does it inhibit the yeast?Yes.
Yes.
I just sprinkle it in.
Here's the funny part: not supposed to oxygenate the wort with dry yeast. That makes sense from a LODO point of view, in that we've worked hard to avoid oxidizing the wort all through the process only to intentionally add O2 prior to pitching.
But the dry yeast is supposed to be ready w/o O2. I've talked to the Fermentis people and they argue that the yeast in dry form are packed with sterols and such which is supposed to be enough to support budding off of new cells. Since O2 is used to make sterols and to support cell wall construction, that makes sense. What doesn't is that there'd be enough for a few generations of cell creation.
But it seems to work. I recently used dry yeast in a brew, no oxygenating the wort, and it worked just fine. It just seems so counter to what would seem to be necessary.
Then there's the problem of removing sulfites. If you don't get them out, does it inhibit the yeast?
I oxygenate for the above reason.
I like to use dry yeast and I started to make vitality starters. May not be necessary but I had issues with more than 48 hours before I saw activity, the activity was very slow or sluggish. I did the no oxygenate and sprinkled on yeast. Decided that was the last time to do that.
Now I always oxygenate and pitch active yeast.
That's a well know fact about dry yeast. The hydration/rehydration process is extremely stressful to yeast and will influence its behaviour for several generations. Most notable effects are underattenuation and reduced ester production (try making a traditional Bavarian Hefe with dry yeast and you'll soon give up in despair). After a few repitches it all goes back to normal and the yeast will express the character that is typical for the strain it belongs to.I don't know why.
You have to consider that if you oxygenate wort prior to pitching all that O2 will be taken up by first-generation cells during the lag phase. No oxygen will be available to subsequent generations for sterol synthesis and hence the sterol inherited from the parent cells is all that will be available down the road.But the dry yeast is supposed to be ready w/o O2. I've talked to the Fermentis people and they argue that the yeast in dry form are packed with sterols and such which is supposed to be enough to support budding off of new cells. Since O2 is used to make sterols and to support cell wall construction, that makes sense. What doesn't is that there'd be enough for a few generations of cell creation.
You have to consider that if you oxygenate wort prior to pitching all that O2 will be taken up by first-generation cells during the lag phase. No oxygen will be available to subsequent generations for sterol synthesis and hence the sterol inherited by the parent cells is all that will be available down the road.
The manufacturer is claiming that dry yeast has sterol reserves at the time it undergoes drying that are equivalent to what liquid yeast would develop if pitched into properly aerated wort, so that the two processes are completely equivalent from a cell growth standpoint.
Actually, I meant from the parent cells. Got my prepositions mixed up...I assume you mean daughter cells?
Oxygen is not only used for sterol synthesis, so in the presence of sufficient sterol reserves the O2 will be used for other methabolic pathways, not least the respiratory methabolism of sugar. Yeast cannot generally have more than 10% of their dry weight as sterols, above that synthesis will stop.This I understand, at least, the manufacturer's claims. What I've understood to be the case is the parent cells are packed with sterols, enough to allow for cell wall building of subsequent daughter cells.
What are they doing if there's more oxygen present? Making even more sterols? Is there a limit to how many/much sterols there can be in a cell?
And what about the daughter cells? How many sterols did they inherit, if any, from the parent cells? Or are they creating sterols differently in the absence of oxygen?
I need to go back and re-read White and Zainesheff's "Yeast" book--I think there's an alternate metabolic pathway to creating sterols, but can't remember for sure.
That's a well know fact about dry yeast. The hydration/rehydration process is extremely stressful to yeast and will influence its behaviour for several generations. Most notable effects are underattenuation and reduced ester production (try making a traditional Bavarian Hefe with dry yeast and you'll soon give up in despair). After a few repitches it all goes back to normal and the yeast will express the character that is typical for the strain it belongs to.
Off Topic - You mind dropping in there? Adding anything you're doing for hefeweizen.That's a well know fact about dry yeast. The hydration/rehydration process is extremely stressful to yeast and will influence its behaviour for several generations. Most notable effects are underattenuation and reduced ester production (try making a traditional Bavarian Hefe with dry yeast and you'll soon give up in despair). After a few repitches it all goes back to normal and the yeast will express the character that is typical for the strain it belongs to.
I love the repitch idea! - Thanks!
I also do the ferulic acid rests at 113F and open ferment to allow more ester formation.
From my understanding:
Clove (Phenolic)
A) From mashing with a ferulic acid rest
B) Supposedly cooler fermentation.
Banana (Ester)
A) From yeast, however open fermentation less CO2 to inhibit esters.
B) Supposedly warmer fermentation.
C) Multiple Generation Repitches
Adding C) thanks to you.
I'll pm you since this off topic.Fixed it.
Off topic.Fixed it.
Mobile PM won't send....I'll pm you since this off topic.
Trying to get back on topic.Any low oxygen brewers out there use dry yeast?
Do you get good results?
How do you pitch it?
So, if someone used the dry WB-06 or Danstar Munich. You would want to do multiple regens. Either yeasts would change with repitches?Fixed it.
But one reason I don't like dry yeast is that IME I get very poor and abnormal performance in the first generation whether direct pitched, rehydrated, or propagated through a couple of starter steps. Lag times many times greater than the ~5 hours I expect with both ales and lagers pitched with liquid yeast, and abnormal attenuation, flocculation and beer pH are among these problems. I don't know why. A couple of generations in, things are fine, but I don't care to make bad beer to get to the good.
Yes, I've done starters with dry yeast, even 2 stage, and while it improves lag time, I still find odd attenuation (unusually high or low, strain dependent) and still the most perplexing thing: first generation dry yeast, even with a starter, results in very low beer pH (3.7-3.8, e.g., where normal performance for the strain would result in pH >4.2.) So I wouldn't be surprised if your flavor issues are in fact pH related. I really wanted to find that dry yeast would be a very convenient source for a new pitch without propping up, or at least a backup supply. But I'm just not comfortable with it.
For my next brew with dry yeast I will rehydrate and then use a vitality starter (4 hours on a stir plate, i.e. pitching at high kräusen).If you do find yourself needing to use dry yeast for some reason, try making a starter.
I've been doing my own vitality starter thing. I make canned starter pints from dry malt extract. Hop, then pressure cook, cool and refrigerate. Using ball or mason jars.Faster oxygen scavenging by the yeast is the goal here, but also avoidance of off-flavors.
I guess I was hoping perhaps someone with a DO meter had monitored the oxygen level after oxygenating a direct pitch vs proper rehydration.
Direct pitch vs rehydration without oxygenating would be interesting too, but excessive residual sulfite might be a concern.
Only one of my three LOB attempts has had the epic fresh grain flavor (and also outstanding hop flavor), and that was with dry yeast rehydrated "correctly".
As I work on tightening my process I'm wondering how much of an effect this has, and which way is best.
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