pitching at bottling - follow-up question (s)

Mashing, fly sparging, batch sparging, dry hopping, late additions. Have an idea you want to bounce or stop by and share your experiences here.

Moderator: Post Moderators

Post Reply
bsmith
Posts: 4
Joined: Fri Jun 13, 2008 7:05 am

pitching at bottling - follow-up question (s)

Post by bsmith »

Thanks for the replies from my last post re: underpitching my suprisingly high gravity ale ('pitching at bottling' post). I brewed the batch on 6/2/08 and pitched a 1 liter starter of WLP550, OG 1.096. I racked to a carboy ("secondary") on 6/9/08, with the gravity at 1.054. As of yesterday, 6/18/08, the gravity is still at 1.054.

I am now looking at pitching another yeast into the "secondary" and curious about yeast attenuation range recommendations and strains. I'm just guessing, but at this gravity, would I want to stay away from 'low' attenuating yeast strains? I've heard good neutral yeast strain recommendation like California Ale (WLP051?), Irish Ale WLP004, US05, in addition to another slant of 550 - mostly medium attentuating buggers that are more nuetral. Another thought I have is experimenting with Brett. What do those with experience think about me pitching a Brett. strain in this ale? I see that Brettanomyces bruxellensis WLP650 is a "classic strain used in secondary for Belgian styles". There was no attenuation % listed next to this (I'm guessing it may be on the high side). I have not used a Brett. yet and very curious about properly (carefully!) using it. If anyone has any suggestions or tips, I would greatly appreciate it. Thanks and happy brewing!

bsmith
User avatar
brahn
Site Admin
Posts: 1799
Joined: Wed May 31, 2006 5:12 pm
Location: Tustin, CA
Contact:

Post by brahn »

Personally, I would probably go with the Brett. But not everyone likes the flavors that it produces. Have you had any beers made with it before? If not, I'd buy one (or many!) and try them first to see if you like that character. Maybe and Orval or Avery 15. Orval uses the Brett as a secondary yeast, but I'm sure their normal strain gets the beer well below 1.054 before they add it. There are different strains of Brett too, so liking one may not translate to liking another.

I haven't used Brett yet, but I know that in lambic brewing at least it can take a long time for the Brett to do it's thing.
User avatar
brahn
Site Admin
Posts: 1799
Joined: Wed May 31, 2006 5:12 pm
Location: Tustin, CA
Contact:

Post by brahn »

BTW, I just saw this message on TastyBrew where someone had a similar problem. He talked to the brewmaster at his local rock bottom and his suggestion was to oxygenate the beer and add more yeast. That might give your new yeast a better chance at doing their thing. I'm a bit skeptical about adding oxygen this late in the game, though.

http://www.tastybrew.com/forum/thread/141137
User avatar
kevinham
Posts: 623
Joined: Wed Feb 27, 2008 11:37 am
Location: Orange, CA
Contact:

Post by kevinham »

Wow, that is the first time in my admittedly short experience brewing that I have ever heard that being recommended. I always heard as soon as fermentation starts that is a big no-no. Now I am interested.
Kevin
User avatar
brahn
Site Admin
Posts: 1799
Joined: Wed May 31, 2006 5:12 pm
Location: Tustin, CA
Contact:

Post by brahn »

I had heard of adding oxygen a few times over the first day or so, but not beyond that. I see the logic in the recommendation, but I still don't know if I believe it. Then again, if your beer is stuck at 1.050, what do you have to lose by trying it?
User avatar
Oskaar
Posts: 979
Joined: Tue Apr 12, 2005 7:18 pm
Location: Sunny So Cal

Post by Oskaar »

Here is a post from Gotmead.com that I made a while ago. Oxygen and Yeast need each other during the first stages of fermentation (usually the first 72 hours plus a day or so) of fermentation. The below addresses aeration during the early stages of fermentation, and the need for nutrient (nitrogen). While this is specifically directed at mead and wine, the physiology of the yeast is constant. Without O2 during the early stages of fermentation your yeast will not develop optimally. Also remember that concerns about oxidizing your beer are valid, but generally that would be after the the aggressive fermentation during the first three days. The vigorous off-gassing of CO2 will strip any unused oxygen from the cells prior to degradation into an oxidative reduction.

The comments are a combination of emails, conversations and excerpts I've collected from Dr. Clayton Cone of Lallemand, Danstar, Lalvin who are one of the leading producers of yeast throught the world.

Regarding Aeration/Oxygenation of yeast during the first 1/3 of fermentation:

Basics: (From Dr. Clayton Cone of Lallemand Yeast Laboratories)

Yeast needs a trace amount of oxygen in an anaerobic fermentation such as brewing to produce lipids in the cell wall. Without O2 the cell cannot metabolize the squalene to the next step which is a lipid. The lipids make the cell wall elastic and fluid. This allows the mother cell to produce babies, buds, in the early part of the fermentation and keeps the cell wall fluid as the alcohol level increases. With out lipids the cell wall becomes leathery and prevents bud from being formed at the beginning of the fermentation and slows down the sugar from transporting into the cell and prevents the alcohol from transporting out of the cell near the end of the fermentation. The alcohol level builds up inside the cell and becomes toxic then deadly.

In a very general view:

At each doubling it will split the lipids with out making more lipids (no O2). The first split leaves 2.5% for each daughter cell. The second split leaves 1.25% for each daughter cell. The next split leaves 0.63%. This is the low level that stops yeast multiplication. Unless you add O2 the reproduction will stop.

If you are shooting for a 3-5% alcohol beverage this is no problem. It is when you produce higher alcohol mead, wine or beer and inoculate at a lower rate that you need to add O2 to produce more yeast, and for alcohol tolerance near the end of fermentation. You definitely need added O2 when and if you reuse the yeast for the next inoculum.

Yeast prefer that the nutrients be added in increments over the first 1/3 of the fermentation. When all of the nutrients are added only at the beginning a large cell mass is produced with each cell having a low protein content. This low protein content makes it difficult to complete the fermentation and withstand the alcohol toxicity near the end. By adding the nutrients, primarily Nitrogen, in increments results in less, but adequate, yeast growth with each cell having a larger amount of protein. High protein yeast ferment faster and withstand alcohol toxicity better than low protein yeast.

Yeast sugar transport systems that bring the sugar into the cell at a prescribed rate, contain nitrogen. Some of their half life span is about two hours, so new transport enzymes must be generated constantly. This requires a fresh source of available nitrogen.

Yeast require a steady source of nitrogen through out the growth phase to produce DNA, RNA, amino acids, proteins and other cell components. If the sulfur containing amino acid skeleton is not available to receive the H2S as the yeast produces it, the yeast will expel it out of the cell resulting in rotten egg odor.

My comment here is that it is critical to remember that yeast are still reproducing during the stationary phase, and to do this effectively, especially in high sugar musts, they need oxygen as well nutrients including nitrogen (for protein synthesis), sterols and fatty acids (for maintaining alcohol resistance and permease activity). In addition, inactivated yeast cell walls (yeast hulls) will adsorb medium-chain fatty acids that are toxic to yeast, and provide nucleation sites to help keep the yeast in suspension. If you find your fermentation slowing to a crawl (as in the example above where the wert is at 1.050) then try adding yeast hulls at a rate of about .75 grams/gallon of wert. They will help to adsorb those medium-chain fatty acids that may be causing your ferment to stick. if that doesn't work, then a nutrient addition appropriate for the stage of fermentation would be the next remedial action.

Also one must be mindful that yeast produce 30x times as much alcohol in the growth phase as it does in the stationary phase. If you are not dosing your yeast with a fresh supply of nitrogen and keeping the O2 level up for the new generations, then your yeast will stress and produce off aromas, flavors and characters.

As mentioned in the intro, nitrogen additions are directed more at wine and mead because beer has a more complete nutrient base. Early on however supplemental doses of nitrogen derived from ammonia salts is beneficial. Later additions (and this is more toward wine) should be made in the form of amino nitrogen (generally from inert yeast hulls) because the yeast are past the stage of using nitrogen derived from ammonia salts, and additions of nutrient based on ammonia phosphates will leave a salty flavor in your beer, mead or wine.

Hope this helps,

Oskaar
Don't go into the Pimped-Out-Refrigerator Jack!
User avatar
spkrtoy
Posts: 2893
Joined: Thu Sep 30, 2004 4:04 pm
Location: Orange, Orange County Calif.

Post by spkrtoy »

Oskaar wrote:Here is a post from Gotmead.com that I made a while ago. Oxygen and Yeast need each other during the first stages of fermentation (usually the first 72 hours plus a day or so) of fermentation. The below addresses aeration during the early stages of fermentation, and the need for nutrient (nitrogen). While this is specifically directed at mead and wine, the physiology of the yeast is constant. Without O2 during the early stages of fermentation your yeast will not develop optimally. Also remember that concerns about oxidizing your beer are valid, but generally that would be after the the aggressive fermentation during the first three days. The vigorous off-gassing of CO2 will strip any unused oxygen from the cells prior to degradation into an oxidative reduction.

The comments are a combination of emails, conversations and excerpts I've collected from Dr. Clayton Cone of Lallemand, Danstar, Lalvin who are one of the leading producers of yeast throught the world.

Regarding Aeration/Oxygenation of yeast during the first 1/3 of fermentation:

Basics: (From Dr. Clayton Cone of Lallemand Yeast Laboratories)

Yeast needs a trace amount of oxygen in an anaerobic fermentation such as brewing to produce lipids in the cell wall. Without O2 the cell cannot metabolize the squalene to the next step which is a lipid. The lipids make the cell wall elastic and fluid. This allows the mother cell to produce babies, buds, in the early part of the fermentation and keeps the cell wall fluid as the alcohol level increases. With out lipids the cell wall becomes leathery and prevents bud from being formed at the beginning of the fermentation and slows down the sugar from transporting into the cell and prevents the alcohol from transporting out of the cell near the end of the fermentation. The alcohol level builds up inside the cell and becomes toxic then deadly.

In a very general view:

At each doubling it will split the lipids with out making more lipids (no O2). The first split leaves 2.5% for each daughter cell. The second split leaves 1.25% for each daughter cell. The next split leaves 0.63%. This is the low level that stops yeast multiplication. Unless you add O2 the reproduction will stop.

If you are shooting for a 3-5% alcohol beverage this is no problem. It is when you produce higher alcohol mead, wine or beer and inoculate at a lower rate that you need to add O2 to produce more yeast, and for alcohol tolerance near the end of fermentation. You definitely need added O2 when and if you reuse the yeast for the next inoculum.

Yeast prefer that the nutrients be added in increments over the first 1/3 of the fermentation. When all of the nutrients are added only at the beginning a large cell mass is produced with each cell having a low protein content. This low protein content makes it difficult to complete the fermentation and withstand the alcohol toxicity near the end. By adding the nutrients, primarily Nitrogen, in increments results in less, but adequate, yeast growth with each cell having a larger amount of protein. High protein yeast ferment faster and withstand alcohol toxicity better than low protein yeast.

Yeast sugar transport systems that bring the sugar into the cell at a prescribed rate, contain nitrogen. Some of their half life span is about two hours, so new transport enzymes must be generated constantly. This requires a fresh source of available nitrogen.

Yeast require a steady source of nitrogen through out the growth phase to produce DNA, RNA, amino acids, proteins and other cell components. If the sulfur containing amino acid skeleton is not available to receive the H2S as the yeast produces it, the yeast will expel it out of the cell resulting in rotten egg odor.

My comment here is that it is critical to remember that yeast are still reproducing during the stationary phase, and to do this effectively, especially in high sugar musts, they need oxygen as well nutrients including nitrogen (for protein synthesis), sterols and fatty acids (for maintaining alcohol resistance and permease activity). In addition, inactivated yeast cell walls (yeast hulls) will adsorb medium-chain fatty acids that are toxic to yeast, and provide nucleation sites to help keep the yeast in suspension. If you find your fermentation slowing to a crawl (as in the example above where the wert is at 1.050) then try adding yeast hulls at a rate of about .75 grams/gallon of wert. They will help to adsorb those medium-chain fatty acids that may be causing your ferment to stick. if that doesn't work, then a nutrient addition appropriate for the stage of fermentation would be the next remedial action.

Also one must be mindful that yeast produce 30x times as much alcohol in the growth phase as it does in the stationary phase. If you are not dosing your yeast with a fresh supply of nitrogen and keeping the O2 level up for the new generations, then your yeast will stress and produce off aromas, flavors and characters.

As mentioned in the intro, nitrogen additions are directed more at wine and mead because beer has a more complete nutrient base. Early on however supplemental doses of nitrogen derived from ammonia salts is beneficial. Later additions (and this is more toward wine) should be made in the form of amino nitrogen (generally from inert yeast hulls) because the yeast are past the stage of using nitrogen derived from ammonia salts, and additions of nutrient based on ammonia phosphates will leave a salty flavor in your beer, mead or wine.

Hope this helps,



Oskaar
Wow! Pete, I'm going to print this out and try to read it if I ever have trouble sleeping.
<kidding, tongue 'n cheek> <yawning> <er, my brain hurts> <WOW>

Great, to the point information! Just the info us lowly brewers need to know as opposed to bogus info from some of the other "brewboards" out there disseminating <sic> bad or downright wrong info.
Cheers,
Lyn
Everybody has the right to be stupid. Some people abuse the privilege.

I hope life isn’t a big joke, because I don’t get it.
What I don't Know Far out weighs what I do.
User avatar
brahn
Site Admin
Posts: 1799
Joined: Wed May 31, 2006 5:12 pm
Location: Tustin, CA
Contact:

Post by brahn »

Reading Oskaar's post, it sounds to me like his recommendation would be to add nutrients in the form of yeast hulls. But, it also sounds like adding oxygen would be fine. It seems pretty reasonable that a wort stuck at 1.050 would still produce a pretty vigorous fermentation and plenty of co2 to scrub out the o2. Otherwise we wouldn't oxygenate wort starting at 1.050, right? In this case, where he's already racked off the yeast, I don't think adding just the nutrient would do much and adding o2 with new yeast would let the yeast grow healthier at the start of it's fermentation.

Maybe I'm missing something, but it seems like adding o2 to a fermentation stuck at this high of a gravity might be a good idea.
User avatar
Oskaar
Posts: 979
Joined: Tue Apr 12, 2005 7:18 pm
Location: Sunny So Cal

Post by Oskaar »

Yeah, in cases like this a fresh pitch and some good aeration/oxygenation should work well. If one is timid they may try the addition of yeast hulls to adsorb those fatty acids that are toxic to the fermentation. If that doesn't get the ferment going strong, then I'd recommend allowing the yeast hulls to settle out, racking and repitching with some aggressive aeration.

Cheers,

Oskaar
Don't go into the Pimped-Out-Refrigerator Jack!
bsmith
Posts: 4
Joined: Fri Jun 13, 2008 7:05 am

thanks!

Post by bsmith »

Thanks everybody for the useful information. I'm heading up to the homebrew store tomorrow to pick up WLP650. I'll get a starter rolling, pitch, aerate well and keep my fingers crossed. After the fermentation settles down, I'll rack to another vessel and give it some time. I'll post with info when the ale progresses. Thanks again!
brew on,
bsmith
User avatar
brahn
Site Admin
Posts: 1799
Joined: Wed May 31, 2006 5:12 pm
Location: Tustin, CA
Contact:

Post by brahn »

The aeration comments were more based on adding more saccharomyces to the fermentation. Brettanomyces is a different animal and I don't know if you'd want to aerate when adding it.
Post Reply