Oxygenating Dry Yeast issue

[mongoose33]

A little background: I've been away from HBT for a while given my involvement in a local brewery (long story there, ask Q's via PM). Among the discussions we had there, between me and a couple of brewers, was about oxygenating dry yeast...or not.

This brewery used dry yeast exclusively; I don't have a problem with that provided you can get the strains you want, and it's certainly easier than making starters with liquid yeast and then oxygenating.

But these guys oxygenated even when using dry yeast, which to me doesn't make sense. We agreed to disagree on that. I did brew a beer for them using some LODO techniques, didn't oxygenate using dry yeast, and it sold well.

Since dry yeast has greatly improved over the years to the point where you don't have to oxygenate the wort prior to pitching, I celebrate the idea of not oxygenating when using dry yeast: I don't want to add any unnecessary oxygen at any point ever, if I can avoid it. And intentionally oxygenating the wort when it's unnecessary simply brings oxidation of malt and hop flavors and aroma into play. I don't want that (who does?).

Watching a webinar this week with Tobias Fischborn of Lallemand and Chris White of White Labs, and they were discussing dry yeast. They showed graphs indicating virtually no difference in final gravity, in speed of fermentation--in other words, there was nothing I could see that would recommend against using dry yeast.

Chris White recommended oxygenating with dry yeast anyway, so I asked this question (paraphrasing): "what degree of oxidation degradation to malt and hop flavors and aroma do you think obtains if I oxygenate when using dry yeast?"

[Edited to add: I should have included this, and Red Over WHite's comment below reminded me of it--the not oxygenating only works for first generation; if repitching then oxygenating is needed, and Chris White noted this.]

The short answer--and their answers weren't necessarily short--was that there doesn't appear to have been much done about that subject. They seemed to like the idea as a possibility, but I was hoping for a more definitive answer. That's ok, they don't have to know everything.

But it's been my belief that oxygenating wort that doesn't need to be oxygenated can't do anything but harm the resulting beer, muting flavors and aromas. My beers can last on tap up to 6 months with virtually no degradation over time, which I attribute to the low-oxygen approach.

Anyone here have views on this subject? Unless I need a strain of yeast I can't get in dry and would have to make a starter, I can't see any benefit to oxygenating with dry yeast. What do you think?

(Link to that webinar; my question is at the 54:30 point. Webinar )

 

[Red over White]

I have not found a need to oxygenate on generation 0. I have repitched generations 1, 2 & 3 successfully without oxygen as well by using goferm protect evolution in place of oxygen at pitch. By successfully, I mean fermentation tracked normal through out and sensory was as it should be.

I am firmly in the vitality starter camp with dry yeast. A dry yeast vitality starter with a 4 hour head start reduces lag time and will double or triple the performance in the first 24 hours vs simply sprinkling it in at pitch. Dropping the wort pH faster and chewing through 3x more points in the first 24 hours are important to me. Many brewers feel that this step is unnecessary, however I feel that proofing the yeast and jump starting a strong fermentation are too important for me to skip.

On another note, I have and do use pure oxygen to pressurize only the headspace of my all rounders on generations 1, 2 & 3. Because the yeast is very active and the oxygen slowly diffuses in, the yeast will consume it at a rapid pace. Does it oxidize the wort? Sensory didn't show that next to gen 0. One data point from my brewhouse with a couple tasters with reasonably good palates, but not scientific research with lab results.

 

[mongoose33]

I have not found a need to oxygenate on generation 0. I have repitched generations 1, 2 & 3 successfully without oxygen as well by using goferm protect evolution in place of oxygen at pitch. By successfully, I mean fermentation tracked normal through out and sensory was as it should be.

I am firmly in the vitality starter camp with dry yeast. A dry yeast vitality starter with a 4 hour head start reduces lag time and will double or triple the performance in the first 24 hours vs simply sprinkling it in at pitch. Dropping the wort pH faster and chewing through 3x more points in the first 24 hours are important to me. Many brewers feel that this step is unnecessary, however I feel that proofing the yeast and jump starting a strong fermentation are too important for me to skip.

On another note, I have and do use pure oxygen to pressurize only the headspace of my all rounders on generations 1, 2 & 3. Because the yeast is very active and the oxygen slowly diffuses in, the yeast will consume it at a rapid pace. Does it oxidize the wort? Sensory didn't show that next to gen 0. One data point from my brewhouse with a couple tasters with reasonably good palates, but not scientific research with lab results.

Funny thing about these posts and such: we (at least I!) tend to assume others do similar things that I do. I don't use successive generations but the point is well taken, and in fact in that webinar they talked about oxygenating with subsequent generations since at that point it's not materially different than using liquid yeast.

Would you describe how you do a vitality starter with dry yeast?

I got to the point with liquid yeast that I'd try to time the starter such that I'd pitch it (entire 1-liter for a typical batch, no decanting) into the wort at about 15 hours after beginning the starter. That is, if I was going to plan to pitch at noon, I'd begin the starter at 9pm the night before. My rationale (which sounds similar to yours) was that I wanted that starter to go in at more or less peak krausen, and the lag would be typically in the 4-5 hour range. I wanted that fermentation to take off to outcompete any nasties that are in there, and sooner is better.

I'd also oxygenate the starter wort.

But anything I can do to get dry yeast going faster, while at the same time not oxygenating the wort, sounds to me like a good idea.

 

[wepeeler]

Most everywhere I've read says first gen dry yeast comes packaged with all the necessary nutrients and doesn't need oxygenation. After that, treat it like liquid yeast and oxygenate future batches.

Research indicates that liquid yeast takes up all oxygen in wort within 30 min from pitching.

 

[Red over White]

Funny thing about these posts and such: we (at least I!) tend to assume others do similar things that I do. I don't use successive generations but the point is well taken, and in fact in that webinar they talked about oxygenating with subsequent generations since at that point it's not materially different than using liquid yeast.

Would you describe how you do a vitality starter with dry yeast?

I got to the point with liquid yeast that I'd try to time the starter such that I'd pitch it (entire 1-liter for a typical batch, no decanting) into the wort at about 15 hours after beginning the starter. That is, if I was going to plan to pitch at noon, I'd begin the starter at 9pm the night before. My rationale (which sounds similar to yours) was that I wanted that starter to go in at more or less peak krausen, and the lag would be typically in the 4-5 hour range. I wanted that fermentation to take off to outcompete any nasties that are in there, and sooner is better.

I'd also oxygenate the starter wort.

But anything I can do to get dry yeast going faster, while at the same time not oxygenating the wort, sounds to me like a good idea.

I always freeze 1 liter of wort from every batch and use it to make two 500ml vitality starters (I brew at least 10 gal batches). First thing on brewday I boil 1 tsp goferm protect evolution and 500ml wort in each flask for 5 mins, force cool and pitch the dry yeast. I gently swirl them periodically to knock out co² but not to add oxygen. The yeast will have about 4 hours in the starter prior to pitching and have a significant impact on fermentation.

Dry pitching will see 1-3 points in 24 hours for most dry yeast for me, vitality starters will see 6-8+ points in the same 24 hours. Typically, I see the second 24 hrs double the amount of points consumed in the first 24 hours, i.e. if 6 points were chewed in the first 24 hours, 12 points will be consumed in the second 24 hours for a total of 18 points in aggregate.

Some dry yeast is fantastic on the first pitch, some get much better on subsequent generations. I do ferment under pressure to simulate static pressure of big breweries ccv's, to emulate similar flavors profiles they get from their yeast with their tank heights. Pressure has been a game changer and is an invaluable lever for us homebrewers.

 

[McMullan]

Not needing to to oxygenate wort was always noted in published brewing science literature as one of the benefits of using dry brewer’s yeast. It seems some home brewers, whilst adopting good brewing practice in terms of aerating wort, got confused then propagated a myth. Then, a few years back, a dry yeast company pulled off a cheeky PR stunt and claimed “it’s not necessary to oxygenate wort when using our yeast”. Dry yeast generally have no requirement for O2. They got all O2ed up during the commercial production process and come with membranes fully equipped with all the lipids to fuel enough cell budding. However, they still mop up any O2, if they’re active. It just doesn’t get channeled into building lipid membrane. O2 is toxic. Living cells need to deal with it by default. There are potential oxidation risks during the extended ‘lag phase’ often observed when pitching dry yeast. Obviously, these things happen at a rate, not all-or-nothing. So, when oxygenating wort, unnecessarily or not, dry vs wet yeast, we don’t really want an extended lag phase delaying things.

The people at that brewery haven’t got a clue about pitching the best yeast, a brewer’s best friend. Shocking business decision for “pros” to just pitch dry yeast. The first pitch is considered aberrant compared with subsequent repitchings. It shows how much they don’t know or care about the product they’re selling. They’ll probably struggle to survive once their marketing gets tired.

 

[Tartan1]

Some dry yeast is fantastic on the first pitch, some get much better on subsequent generations. I do ferment under pressure to simulate static pressure of big breweries ccv's, to emulate similar flavors profiles they get from their yeast with their tank heights. Pressure has been a game changer and is an invaluable lever for us homebrewers

Are all you brews done under the same pressure or are they varied as to the style of beer or yeast strain you are using? What would a typical pressure setting be for your fermentation schedule?

 

[hottpeper13]

I'm with Red over White. I pull 1 qt after 10 min of boiling and put in freezer to chill. After chilling main batch the qt is ready for the dry yeast. After the wort has settled for 4 or so hrs I'll pump to FV and pitch. I use BRY-97 and Notty which are slow starters(sometimes 36 hrs). I have positive pressure after 6 or so hrs,and a foam cap by morning. Yes I oxygenate the wort.

 

[mongoose33]

The people at that brewery haven’t got a clue about pitching the best yeast, a brewer’s best friend. Shocking business decision for “pros” to just pitch dry yeast. The first pitch is considered aberrant compared with subsequent repitchings. It shows how much they don’t know or care about the product they’re selling. Thbey’ll probably struggle to survive once their marketing gets tired.

They are in fact now closed but it had relatively little to do with the quality of the beer (though that figured into it initially). I had the great fortune to brew my Amber (something they hadn't done and for which I have a nice recipe) and get it on tap. The Amber broadened their offerings and made the brewery more accessible to those who aren't and never will be beer snobs.

[Interlude: My belief is that unless I have a friend or friends who will be ruthless in their assessment of my beer--and I do have one who's great that way--the only true way to evaluate my beer is to see if people will have a second one. While there may be a lot of reasons why people might not have a second one, primarily such as not liking the style, there's generally only one reason why they have a second one: they like it. So I was very excited to get my beer on tap at a brewery and see if people would buy it, and then buy it again. Short answer: they did. The Amber is not my signature beer, which is a dark lager (Darth Lager), but I never got the chance to try some of my other recipes, which bummed me out.]

As far as breweries using dry yeast, I've known of at least 3 who do that. If you don't or can't handle repitching well, then it's a way to ensure consistency each time beer is brewed.

The closed brewery struggled but the beer was improving. They had 3 or 4 that I thought were pretty darned good (my Amber aside). But the initial beers were mostly iffy, which is not how I'd want to open a new brewery.

I'm tempted to start a thread with a post-mortem about the brewery. They made, by my estimation, at least six mistakes which couldn't be overcome--and that could and should have been anticipated. That in part was the owner (who wasn't the brewer!) relying on the advice of the main brewer, whose...hubris, I suppose...kept him from soliciting other advice.

 

[Red over White]

Are all you brews done under the same pressure or are they varied as to the style of beer or yeast strain you are using? What would a typical pressure setting be for your fermentation schedule?

I do have different schedules for the yeasts I use regularly that were developed from side by side ferments of the same batch. Even though growth isn't really hampered by setting some head pressure, I will typically allow the fermenters to natively build pressure. How fast this happens with generation 0 is based on the headspace of the fermenter, temperature and pitch rate. Generation 1 and and beyond, if pitched quickly from the last batch will build pressure extremely fast. This can be slowed some by attaching a keg for purging which essentially increases the headspace of the fermenter with just a jumper between fermenter and keg and the spunding valve on the keg.

For an ale yeast like Verdant, I will allow it to build pressure to 10 psi until high kräusen and then adjust the pressure for desired cabonation at the temperature it will be when kegged. For a lager yeast like S-23 or S-189 I will let it free rise to 30 psi and then adjust it on the tail end of fermentation to be at the proper carbonation when packaged. I think it's important to adjust temperature and pressure to find what you prefer in the glass. With lager yeast under pressure I like my fermenters at 60°F and ales at 66-70°F. It has taken many split batches for me to find my goldilocks zone that gives me that nice round creamy mouthfeel from fermenting under pressure as well as the desired ester profile or lack thereof. Cheers and Merry Christmas!