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> chat transcripts with return guest David Logsdon, Founder, Owner, & Lab manager of WYeast
kroyster
post Jul 6 2005, 12:21 PM
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QUOTE
This week's chat will feature guest David Logsdon, Founder, Owner, and Lab manager of WYeast Laboratories. Mr.Logsdon remains involved in brewery operations as founder and Brewmaster at Full Sail Brewing Company and Mt. Hood Brewing Company. The laboratory was founded in the early 1980s as an integral part of the resurgence of craft brewing throughout the world. Mr. Logsdon will be with us on Sunday to discuss yeast cultivation/management as well as other brewing and fermenting topics.


ale: My clock now reads 7:59. Close enough. Mr. Logsdon is using brewdr as his screen name.
brewdr: Hello everyone, Dave Logsdon from Wyeast here...end
ale: Please remember to keep things orderly.
Spectre: ?
ale: Questions need to be preceeded with a "?"
ale: Go Spectre
Spectre: How long do you recomend before a yeast should not be harvested. Or does it depend on the strain?
brewdr: Good Question,typically the best time is about 1-2 weeks after terminal...
Spectre: Ok, after terminal, how long can you store the yeast?
twocents: ok who did that?
brewdr: Some like to harvest from the secondary whichwould be about 1-2 weeks afterthat racking...
Spectre: Which do you think is best, from primary or secondary?
brewdr: For top cropping, about 1/2 - 2/3 through fermentation when the head is dense, before falling...
Spectre: So primary top cropping is best?
brewdr: So to answer your question, about a month for most beers. If they are >5.25 ABV, then not at all... end
brewdr: Primary top cropping generally provides the healthiest yeast...
twocents: ?
Spectre: Ok thanks.
ale: Go twocents
brewdr: Paticularly in high gravity brews where he alcohol goes well above 5.25...end
twocents: are some strains slower than others? I have a 3787 trappist which took about 4 days to expand (not fully) from a feb package...... the starter seemed to multiply slow
twocents: and now the fermentation, while active enuf, is slower than other strains I've used..
twocents: is it a slow strain??
twocents: <end>
brewdr: Most if not all belgian strains are slower to start than ale or lager strains. The condition of the strain, and age does have an impact on the rate of fermentation, along with a couple of other factors...
cdh: ?
brewdr: If it is a high gravity beer, more yeast, or very fresh yeast helps significantly, another variable is the amount of areation provided. High gravity beers are more difficult to get adequate dissolved O2, and need more than lower gravity beers...end
twocents: thanks... I will take it for the type of yeast..
ale: Go cdh
cdh: ? I love that you've gotten the Roeselare blend onto the market. I was wondering about its operating parameters... how warm should it be kept in the secondary to really let all the bugs do their thing? Does it benefit from a long secondary pre-bottling?
brewdr: The blend works well in the 60-75 F range....
ineedacatscan: ?
Spectre: ?
Thomas: ?
brewdr: In secondary, even as low as 50 F activity will continue, but more slowly.The blend traditionaly was aged up to a year or more and blended with a young beer to meet the profile. I have aged beers for 1.5 years before bottling, and that worked very well
brewdr: ...end
ale: Go Catscan
ineedacatscan: what is your opinion on cold pitching? I've seen anecdotal evidence supporting it but it would be nice to hear from a professional on this...3
cdh: thanks for the advice. So I've got a long wait ahead.
brewdr: Good Question, that is a traditional method...
brewdr: Starting on the coolor cold side of fermentation allows more ester formation when the temp is allowed to rise about 1/2 way through fermentation and finish on the warm side...
ineedacatscan: so the yeast gets somewhat acclimated to the initial wort temperature?
brewdr: Brewers get nervous watching a fermentation start slow. When proping or starting with a dormant culture, it is much safer to start on the warm side, and adjust as desired...end
brewdr: I don't know about acclamation...end
ineedacatscan: thank you
ale: Go Spectre
Spectre: Is there any flavor benefits to starting with a lower gravity yeast, then finishing with a higher gravity yeast on big beers, or should high gravity yeast always be used to begin with?
brewdr: Yeast grow musch better in low or moderate gravity worts, even if later fermenting high gravity beers...
brewdr: High gravities are a stress factor for yeast...end
ale: Go Thomas
Spectre: Is that a yes or a no?
Thomas: I'm wondering how many "secret" strains you keep that homebrew stores are able to order, like 2000, 2001, 2002? Are there any you can tell us of? lol
brewdr: Yes, the resulting flavor should be much better...end
brewdr: Those strains were initially held proprietorily and produced for one customer...
brewdr: Now they are ours to produce for all customers and are avaialble...
Thomas: but they're still not listed in your list of strains available
Thomas: (IMG:style_emoticons/brewboard/smile.gif)
brewdr: You will see them on our web site some day soon, I hope. We are doing a major web update...end
Thomas: thanks
ale: ?
Thomas: go ale
Palmetto_Pub: ?
brewdr: The 2000 series strains are a nice addition for brewers maing czech pils. They are all unique...end
Spectre: ?
ale: Dave, What are the major differences between the older XL packs and the newer Activator packs?
brewdr: The new Activator packs have twice the cell count as the old ones...
twocents: ?
brewdr: The cell count (100 billion) is the same pitch rate professional brewers wouls use...end
ale: Go Palmetto Pub.
Palmetto_Pub: Is 1272 the closet to Rogue's Pacman yeast you carry? Or is there another similar yeast? end
brewdr: Thats a tough one...
Palmetto_Pub: lol
brewdr: It is somewhat similar in some aspects. The 1272 is more typical of what you might find in a Bridgeport beer...end
ale: Go Spectre
Spectre: When bottling a barleywine (If aged for more than 3 months in a carboy), should the same strain of fermentation yeast be used, or do you think using a decent dry yeast is ok?
brewdr: A fresh culture of the same strain would be my first choice...
brewdr: Another ale yeast with good attenuation would also work well....end
Spectre: How much of the same strain should be introduced into the process?
ale: Go twocents
twocents: If the activator packs have twice the yeast, just making a starter (which I do with activators as well) and boosting it once or twice achieve the same effect?
brewdr: Pro brewers use 500 million cells per ml...
brewdr: But that might not help you much. One package of yeast is overkill, 1/2 package is plenty...end
ale: ?
Thomas: go ale
Thomas: (if Spectre's question was answered)
Spectre: I'm good. Thanks.
ale: Dave, why is Wyeast relunctant to name their "sources" of yeast?
brewdr: Some brewers probably preferwe didn't...
brewdr: Some brewers change yeast strains, and what they use now could be different...
brewdr: We try to be respectful of their generosity...
Thomas... goes to update the 1272 relation
Thomas: *cough*
brewdr: Some brewers do not care, and when asked we will divulge our sources...end
BobH: have a good 4th everybody, I got to go... thanks dave
cdh: ?
ale: Understood. So where do the big guys get thier yeast from?
brewdr: Many brewers bank a variety of strains...
brewdr: We ship yeast to AB, and many other large brewers as well.....
twocents: ?
brewdr: They are always on the lookout for what might be better than what they now have...
brewdr: Besides us, there are a number of other banks around the world...
brewdr: There is a yeast company from OZ that carries over 1000 yeast strains...
ineedacatscan: ?
brewdr: That make our few hundred seem small, but very good!...end
ale: ...so the yeast doesn't actually come from yhe brewey. It comes from the bank?
brewdr: Way back in time, some good yeast were isolated from a mix of other, more wild strains, so to speak...
brewdr: Wine yeast evolved in much the same way, from the vineyard, we find mixed populations, and isolate out each strain, make wine with them and qualify any or all of the desirable strains....end
ale: Go cdh
cdh: How difficult was it to capture the right character in your blends like the Roeselare and the Dutch Castle? Are you working on bringing to market any other yeasts with unusual character like those two?
brewdr: Belgian strains have a lot of similarities to wine yeast too...end
brewdr: When I visited Rhodenbach back in the early ninties, Peter B. gave me a slurryfrom the brewery...
brewdr: We isolated out each organism, and determined th % mixture of each. Now when we grow thwm up, we remix to the same proportions...
brewdr: My spelling isn't as good as my desire to brew fun beers....
ale: lol
twocents: typos rule
brewdr: We are currently working on a Saison blend to get a mix that performs better than a single strain...
twocents: you doing ok... fit right in
brewdr: Saison yeast are notorious for starting fast and slowing to a crawl about half way through the ferment...
brewdr: They almost always ferment out, but it can take months...
brewdr: Dupont ferments at 30C, to help the process....
brewdr: We hope to find the right mix to keep a steady ferment and great flavor...
brewdr: Fermenting warm is not an issue with this type of beer. Also Duvel stars at about 16 C and finished about 25-26C for similar reasons....end
twocents: hiya bryan
ale: Go twocents
twocents: How do you keep strains pure?, to type?
brewdr: We grow each strain up for testing about every six months...
twocents: if it drifts then, how do you fix it?
brewdr: We reculture to isolate out any potential mutants that may have formed over that period. We then grow the stain in wort/juice and evaluate the fermentation profile...
twocents: wow
brewdr: We also evaluate the flavor profile, cause that is so important. ...
brewdr: When we produce each batch of yeast (weekly) we test it along the wa for purity and viablity...
brewdr: And of course autoclave and sterilize everthing that touches it...
brewdr: We use sterile air filtration as well, along with aceptic handling all along the way...
Spectre: ?
brewdr: Our crew look like drs. in a operating room, gloves, mask smocks and alll..end
twocents: quite a procedure.
ale: lol
brewdr: Thats what it takes, so we can sleep at night and take a holiday from time to time...end
twocents: hahahhaha
ale: Go Catscan
twocents: what's a holilday?
ineedacatscan: at what rate do professional brewers typically pitch e.g. 1 liter of 500 million cells/ML yeast :[/color] 5 gallons of wort.... I suppose I'm curious at what point in making a starter does it become overkill?
brewdr: Oh you know, when the boss gives you an extra beer out of petty cash...end
twocents: hahahhaha
brewdr: Actually it is probably a liter of 500 billion cells per barrel (31 gal)...end
brewdr: You can over pitch...
brewdr: It is more difficult to do than under pitching obviously but...
ineedacatscan: right i just can't imagine that for an ale i need to step up a yeast all that much it seems some people step up multiple times which seems just completely excessive
brewdr: Error to the high side except for german style wheat beers....
brewdr: Underpitching produces more esters typical of that style...
ineedacatscan: through stress on the yeast right?
brewdr: And they also aerate a minimal amount to juice up the esters...
brewdr: It is stress, but a controlled amount....end
ale: Go Spectre
Spectre: Are yeast "mutants" the predecessors to new yeast strains? Or how are new yeast strains developed?
brewdr: Proping too much can actually cause nutrient deficiencies, and problems....end
brewdr: Yeast mutants can become a "new" strain....
brewdr: If their attributes are desirable, then you have something new that, if stabile can become a new strain, it usually has gentic changes at that point...end
Spectre: Ok thanks.
twocents: proping?
twocents: define...
brewdr: Propagatin the yeast in a liter of wort or so...
twocents: oooh, shorthand
brewdr: Then pitching into a larger volume or into the beer....end
ale: It's now past 9:00 Eastern time...
twocents: do we know where our yeasties are??
brewdr: Here it is just beer thirty by my clock....end
ineedacatscan: I HAVE THE SAME EXACT CLOCK
ale: ...Mr. Logsdon is now off of the hook..
brewdr: Thanks for all the questions, email me at dlogsdon@wyeastlab.com if you want any follow up....end
ineedacatscan: thanks for coming out
twocents: thanks brewdr
ale: ...Everything from this point on is a personal gift from Dave.
brewdr: I have a few minutes before i have to fire up the barby...end
ale: ?
ale: Dave, got time for a couple more?
brewdr: go...end
ale: What can you tell us about Sam Smith's yeast?
brewdr: I don't really know much about that strain(s)...
ale: I had the opportunity to brew with it about 10 years ago...
brewdr: We don't have it in our collection that I know of...
brewdr: I think our 1318 might be similar in some ways...end
ale: ...so flocullant that you could almost hear it 'clunk' when you pitched.
brewdr: What di you do with it?...end
ale: I threw it out.
brewdr: That actually looks more like the 1968...end
ale: ?
brewdr: But you can here it clunk!...end
ale: How does one go about freezing yeast?
brewdr: Well my kiddies are looking for dinner...
twocents: goodnight bresdr
twocents: brewdr
brewdr: You need to use glycerol in the solution so that the cells don't rupture....end
brewdr: Have a great fourth! Go out with a bang!!!!!...end
twocents: *********
Thomas: thanks for coming brewdr
ale: Dave, Thanks for coming on board tonight!
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