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Messages - thcipriani

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17
Yeast and Fermentation / Re: Fusel alcohols
« on: October 02, 2012, 09:18:42 PM »
An excess of FAN will cause fusel alcohols—low molecular-weight proteins are also foam-negative. Might be something to look into if you're seeing low head and hot alcohol.

18
Yeast and Fermentation / Re: Microscope
« on: September 03, 2012, 04:54:54 AM »
Be sure to check eBay.  I spen $40+shipping on a cheap student microscope that I've used for the past 3 years. http://www.ebay.com/itm/ws/eBayISAPI.dll?ViewItem&item=380248813512

19
All Grain Brewing / Re: Step Mashing a Hefe...Why?
« on: July 23, 2012, 06:31:58 AM »
I do cell counts for every beer and I can tell you that the calculators are right within a range, but sometimes you'll end up with 100E9 cells total in a 2 liter starter.

How are you determining the viability of the cells?

I don't. I'd like to order methylene violet one of these days…

Excuse: Kai's reply in this thread about why he doesn't stain http://www.homebrewersassociation.org/forum/index.php?topic=5484.msg66305#msg66305

20
All Grain Brewing / Re: Step Mashing a Hefe...Why?
« on: July 22, 2012, 10:04:46 PM »
At best, it's mainly guesswork determining the initial viable cell count, which makes the starter size question, also guesswork.  I seem to recall Denny not worrying too much about this either.

I do cell counts for every beer and I can tell you that the calculators are right within a range, but sometimes you'll end up with 100E9 cells total in a 2 liter starter.

You can use visual queues to tell you when you are getting starters with a low count—they're the 1 starter out of 100 that leave you questioning whether the yeast is just dead.

If you want to pitch at the rate given by the calculator then mrmalty.com is usually right there give or take 30E9 cells. I actually use a 1.020 starter wort with a shaker at 120RPM, so any variability I get is probably from that difference.


On pitch rate?  Honestly, I really don't worry about it very much.  I normally use one XL smack pack of 3068, and may or may not make a starter.  When I make starters, I'm usually making a 1L one, so I'm more interested in getting the yeast active and ready to go than I am in getting a large cell count increase.  I guess I'd agree that repitched 3068 seems to suck in comparison to fresh.  I thought it was because the yeast was unstable (since the beer does seem to go off faster than other styles) but I'll buy the cell count explanation.

Are you talking specifically about weizens here? I get the impression from your book that you mostly do 1L starters and repitch.

21
All Grain Brewing / Re: Step Mashing a Hefe...Why?
« on: July 20, 2012, 10:27:01 AM »
Also, the Eric Warner book quotes many modern German breweries pitching roughly 7E6/mL.

Which book? In German Wheat Beer he states pitching rate should be 10-15m/ml on page 71, and again on page 97.

FWIW he also says you should experiment with fermentation parameters to dial in the flavor you want, but he only lists stuff like temp, open/closed vessels, and wort gravity. He doesn't suggest the pitching rate is one of the variables you should adjust.

For anyone interested, here's an experiment Kai did on this topic: http://braukaiser.com/wiki/index.php?title=Experiment_Pitching_Rate_and_Oxygenation

hmm...
Thought it was German Wheat Beer—definitely in Brewing With Wheat—the part where he talks about Franziskaner (also, possibly, in the section on New Glarus—I'll double check all these sources when I get home tonight).

In any event, when I did my 20E6/mL vs 6E6/mL I emailed Wyeast and it jived with some experiments they did. Hopefully, they won't mind me posting the text in the entirety (hopefully no one on this thread mind, too :))Text below:

Quote
-----Original Message-----
From: thcipriani@gmail.com [mailto:thcipriani@gmail.com]
Sent: Wednesday, January 18, 2012 6:40 PM
To: Customerservice
Subject: Question From Wyeast Labs website for I have general question.


QUESTION:
Hello,

I have a question that pertains to Wyeast 3068 and other of the 'plastic' yeasts that may produce sulfur. I know that these yeast have a propensity to produce sulfur; however, I don't know what makes certain fermentation schemes produce a greater amount of sulfur.

One of my current theories is that older yeast cells have a greater propensity to produce sulfur. I recently pitched a (12°P) hefeweiss beer with 20 million cells/mL and that fermentation was very sulfury. I'm using that information along with a a paper I read from the MBAA recently (it was from 1999, IIRC) that said a beer with a higher pitching rate has a greater amount of older cells in the finished beer since the final cell volume of the finished beer was the same regardless of pitching rate.

Can you provide any info on the 3068 yeast and sulfur  production. Also, can you confirm that these yeast are slightly more elongated than the typical round fat yeast cells when viewed under a microscope. Or is the slightly elongated appearance indicative of something else?

Thanks!

FROM:
Tyler Cipriani thcipriani@gmail.com 80501

-----------------------------------------------
On Fri, Jan 20, 2012 at 9:40 AM, Labservices <Labservices@wyeastlab.com> wrote:
Hey Tyler,

Sorry it took me so long to get back to you.  We don't have info on sulfur production specifically related to 3068.  One thing we know is  3068 does not store well after fermentation.  It will die off quickly.  This coincides with your info on population dynamics with respect to older populations of yeast when using higher pitch rates.  For this strain, it is advised to use low pitch rates around 6 million cells/ml to promote ester production, specifically isoamyl acetate.  At the pitch rates you mentioned, this ester will be at low levels.  Possibly so low that you will not get the banana or bubblegum aromas desired with this strain.

As for cell morphology, yes, it is very normal for the cells to be elongated.  Also, this strain is a chain-former, so it is common to see large groups of attached cells.

Let me know if this answers your questions.


Jess Caudill
Brewer/Microbiologist
Wyeast Laboratories, Inc.
P.O. Box 146
Odell, OR  97044  USA
Phone:  541-354-1335   Fax:  541-354-3449
jess@wyeastlab.com
www.wyeastlab.com

-----------------------------------------------
From: Tyler Cipriani [mailto:thcipriani@gmail.com]
Sent: Friday, January 20, 2012 9:31 AM
To: Labservices
Subject: Re: Question From Wyeast Labs website for I have general question.
 
Hey Jess,
 
Quick followup question about yeast growth and ester formation. You stated that 6 million cells/ml would promote ester production; however, I've read some conflicting information about this.
 
During intra cellular ester formation, from my reading I've surmised, enzymatic reactions create esters using alcohol and an acid - typically, Acetyl CoA. While many authors tend to agree that increased biomass production (i.e. creation of cell walls) reduces the Acetyl CoA that is available for ester production and leads to reduced ester levels in the beer (Narziss 2005, Cone, Noonan 1996, Fix 1999) authors differ with respect to ester production and yeast growth. Fix (Fix 1999) writes that any, "increased activity on the acetyl CoA branch", whatever that means, will increase ester production while other authors (Narziss 2005, Cone) state that increased yeast growth leads to a decrease in esters since more of the acetyl CoA is used for sterol synthesis.
 
Is there more consensus on this topic now? Overall I'm confused about it - hence pitching a hefe (that I normally pitch around 7x10^6 cells/ml ) with double that rate - I was trying to get an increase in esters; however, the excess sulfur production made this "experiment" inconclusive.
 
Thanks for all your help! I just re-read my email and realized that customers like me are likely a giant pain in the ass.
 
Thanks Again,
Tyler
 
Sources:
--------
Cone - http://www.danstaryeast.com/library/yeast-growth
Fix - George J. Fix Ph.D, Principles of Brewing Science, Brewers Publications, Boulder CO, 1999
Narziss - Prof. Dr. agr. Ludwig Narziss, Prof. Dr.-Ing. habil. Werner Back, Technische Universitaet Muenchen (Fakultaet fuer Brauwesen, Weihenstephan), Abriss der Bierbrauerei. WILEY-VCH Verlags GmbH Weinheim Germany, 2005
Noonan - Gregory J. Noonan, New Brewing Lager Beer, Brewers Publications, Boulder CO, 1996
------------------------------------------
Tyler,
 
Yes, customers like you are a total pain in the as[sic].  Just kidding.
 
I am definitely aware of the articles and text that describes lower ester production with higher yeast growth.  But, as you know, what actually happens in practice and what books say and experiments show can be completely different things.  We ran trials using 3068 at pitch rates of 3, 6, 12 and 24 million cells per ml.  The 3 and 6 had strong banana aromas, the 12 million had very slight banana aroma and 24 million and no banana, and for a completely non-technical description, tasted like crap.  More specifically, it had a strong styrene aroma along with burnt aromas.
 
Once we conducted these trials, we helped a ton of breweries refine the flavor profile of beers made from this strain.  Basically most of the breweries were pitching the correct amount on the initial pitch from us.  Upon repitching, they were losing the banana aroma completely.  Most were reptiching 2-3 times the pitch rate of the original.  When they reduced the repitch volumes the banana came back.
 
Jess

22
All Grain Brewing / Re: Step Mashing a Hefe...Why?
« on: July 19, 2012, 11:43:17 PM »
I was planning on making another batch of weizen soon. Over on the HBD board I saw Chris White recommends 5-7m/ml for a weizen. I've never tried pitching one that low, or as high as what Narziss recommends. It sounds like an experiment is in order. It wouldn't be too hard to do a split batch and see which one turns out better.

What I've always thought was weird is that Dan Gordon has said he pitches at 6E6/mL in a hefe AND his original doctoral project was to translate Narziss into English. Why would someone who studied directly under Narziss, who still follows the Rheinhisgibot, go against tradition/teachings like that? I really think the presentation that is quoting Narziss is MISquoting him.

Also, the Eric Warner book quotes many modern German breweries pitching roughly 7E6/mL.

I brewed 2 hefes back-to-back both 1.048—one at 20E6/mL one at 6E6/mL. The idea was that since there would be less Acetyl Co-A used in cell sterol production (in the 20E6/mL) there would be more available for the production of esters (in conjunction with alcohol)—basically, I thought that under pitching was a bad idea and I wanted to prove it to myself.

I ended up proving the exact opposite. The 20E6/mL hef was initially sulfury and then just insipid—boring, some clove, nothing much as far as yeast character really. The 6E6/mL was beautiful—great balance, really nice.

I saw some slides from Neva Parker recently that showed a very wide range of pitching rates that all resulted in the same terminal gravity. Frankly, I think that homebrewers ought to play with pitching rate a bit more. Pitching rate has become a bit too dogmatic recently.

23
Equipment and Software / Re: Aeration? How important is the method?
« on: June 28, 2012, 05:50:01 PM »
Different aeration methods were actually tested scientifically.  Google "Effectiveness of Various Methods of Wort Aeration."  The study basically showed that rocking/shaking the wort for 2 minutes was as effective or better at aerating your wort than any other method.

Glanced at that article it seems like the experiment they conducted was using boiled and cooled water.

From my limited experience I've seen some varience based on gravity of wort.

I have the Milwaukee entry-level DO meter to do some testing – what's been getting me about 11ppm to 12ppm (which may be too high – I like the results though) is pure oxygen in the headspace of a carboy (wort at 62*F) at 2LPM for 10 seconds and then a mix-stir for 1 minute.

Works for me. Maybe could exclude the headspace O2. Atmospheric oxygen at my elevation (~5000ft) is still up around 8.2 mg/L

In case you were wondering the little red tanks of O2 run about 3.5 LPM wide open with most oxygen setups you buy (read: morebeer setup)

24
Equipment and Software / Re: What pH meter do you use?
« on: June 28, 2012, 05:40:50 PM »
Used to have the MW-101 – when it was time to replace the probe on that I moved the Hanna pHep5.

I'm much happier with the pHep5 – no questions when the bugger is calibrated and no questions about when your reading has stabilized.

Personally, I'll never go back.

25
General Homebrew Discussion / Re: 1st round NHC results
« on: May 02, 2012, 08:07:45 PM »
So the problem is 2-fold:
  • Not enough openings for everyone to enter
  • Not enough judges to score existing entries

Why not give people who judged last year the right of "first-refusal"? I.e. open entries a day early to those who judged the year previous.

If judges fill up all slots in all regions you're guaranteed to get more judges the following year which would, in-turn allow for more entries.

This also answers the question of how to better incentivize judges. 

26
Assuming the info below is correct, what upper limit of wort SG's would you feel comfortable pitching a 2 liter starter into?

Too many variables.

I pitch some styles lower than others and some styles much higher than others. I grow much more than 200e9 in a 2L starter.

If you don't have a way to do cell counts or don't trust a sedimented cell volume then the Mr. Malty calculator is your best bet.

27
Yeast and Fermentation / Re: Wyeast 1469...Sulphur??
« on: March 22, 2012, 06:57:53 PM »
you can also try hooking the gas up to the beer out post (use some lube here so it comes off after) and push the co2 through the beer. keep bleeding it off as you do it and see if that speeds it up at all.

That's been my experience with sulfur – tends to blow off after a week or two of purging and refilling the headspace of the keg.

Never turns out the best beer, but it is OK after sulfur dissipates.

My suspicion is that most sulfur comes from yeast stress due to over-pitching AND/OR insufficient FAN.

Recent Trial—German Hefe
  • Pitching rate: 15e6 cells/mL (common is 5–7e6 cells/mL)
  • Result: Complete loss of banana & huge sulfur production & green-beer diacetyl production.
  • Reasoning: Older (less healthy) cell population resulted in stressed yeast – coupled with lack of necessary nutrients to support such a large population of yeast (particularly amino-acids which may be lacking in wheat)

Edit – also saw this article on overpitching/diacetyl – may not be directly useful: http://www.ifrj.upm.edu.my/16%20(4)%202009/11%20IFRJ-2009-112%20Nguyen%20Vietnam%202nd%20proof.pdf

My 2¢

28
Yeast and Fermentation / Re: Wyeast 1469...Sulphur??
« on: March 22, 2012, 06:06:14 AM »
OG is 1.056.  8oz DME in a 1/2 gal starter.  I've always used a wine degasser for aerating the carboy.  Maybe 60 seconds of continuous aeration.  It was a fast starting fermentation.  I've emailed Wyeast to see if this yeast throw sulphur.

That all seems normal.

Did you use any adjuncts, sulfites (campden tablets) or nutrient (DAP, Fermaid K, Wyeast BCN etc)?

29
Yeast and Fermentation / Re: Wyeast 1469...Sulphur??
« on: March 21, 2012, 08:54:31 PM »
Someone tell me I don't have a damned infection.

I doubt you have a damned infection.

Anyone else had anything similar happen with WY1469?

Nope. Never with that yeast.

I am curious – what was your original gravity and what was your approximate pitching rate? Did you oxygenate and, if so, for how long and by what method?

30
Equipment and Software / Re: Cheapest/best wort chilling device.
« on: March 17, 2012, 09:16:17 AM »
The cheapest chilling method is the one you covet – you're going to, at some point, buy the chiller you want so just forgo a few batches and save up for that Therminator you want.

You'll waste a lot of money buying "cheaper" chilling methods.

This is from experience.  I own two IC's, one counterflow and a therminator – could have saved a lot just buying what I wanted in the first place.

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