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Messages - narvin

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886
While the mash is going I decant the cold erlenmeyer flask and transfer the yeast with the stir bar into a one liter beaker.
I put the beaker on the stir plate letting it warm up and re-suspend the yeast.
Once I establish the wort final gravity I then pull 10ml out of the spinning slurry to a 1:100 dilution for a yeast count.
Calculate the pitch rate at this point and toss it in the fermenter.
Works quite well for an accurate yeast count for me!


I was thinking about trying to count again after decanting and before pitching... this sounds like an easy way to do it.  I'll try it with my next batch.

887
All Grain Brewing / Re: Unfermentable, da-dee-dee-da
« on: July 13, 2011, 02:12:28 PM »
Many do not do a mashout, but the principle still applies IMO, that if you steep malted grains after the enzymes have been denatured your OG will rise correspondingly, but so will your FG.  Even if batch sparging, if you drain, then add hot sparge water, let it sit awhile, add grain, let it steep, a similar result happens.


Steeping grains like crystal malts don't need to be mashed since the enzymatic action that converts starch to sugar happened during the malting process.  A portion of the sugars contributed by crystal malts are unfermentable, but you should get the same result whether you steep or mash them.

More on steeping grains:

http://howtobrew.com/section2/chapter13-1.html

http://howtobrew.com/section2/chapter13-2.html

888
Equipment and Software / Re: Mill motor
« on: July 12, 2011, 06:20:48 AM »
Beautiful! 

I wish I had a garage or something... lugging my mill on a board up from the basement (more of a crawlspace) every time I need to brew is a workout in itself  :)

889
The Pub / Re: Once n a while something comes along that ....
« on: July 12, 2011, 06:18:52 AM »
I just find it very funny.

So it would be funny if you your family got hurt or killed because of that kinda driving? Real funny man...



I'm not for a second condoning what the driver does. I'm laughing at the pointless reaction. Are you saying that  because I don't swear at bad drivers I'm putting my family at risk.

No one is saying that, unless you are twisting words.  You are, however, laughing at Phil after making an equally pointless jab at his parenting.

Can you not be a d!#$ for once?

890
The Pub / Re: Once n a while something comes along that ....
« on: July 12, 2011, 05:41:41 AM »
Wow. When you encounter a driver like that, I sure hope you don't use that same language with your 1 year old in the back seat.

Idiot drivers may break my bones, but words can never hurt me.

891
I'm only counting 5 of the 25 "group" squares -- the four corners and the center one.  These are the squares that have 16 smaller squares inside.  I get about 200 cells total.  

200 cells / (0.2 mm^2 * 0.1 mm * (1/10) )     = 100,000 cells / uL = 100 billion cells per L

This is from 4.5 L of liquid, so that would be 450 billion cells.


This is the yeast cake in the fridge after 2 days:



You may be right... even though it was on the stir plate and I tried to pull from the middle of the flask, there may have been more yeast at the bottom and the sample wasn't representative.

892
You're right, and I misspoke... it was more like 20 or maybe 30.  60 is for a carboy of beer, and I specifically dialed it back for the starter.

One more thing to note is that I stained with methylene blue when counting and the viability was around 90-95%.  Is this low for a fresh starter?  5-10% non-viable in the final starter could have been more like 40-50% if they all came from the White Labs vial.

Still, the biggest thing that's throwing me off is the discrepancy between the large volume of yeast cake I have and the cell count.  But perhaps yeast volume is just not an accurate measurement.

893
Anyone do cell counts on their starters?  I've started out of curiosity, but the results are different than what I'd expect.

I've been growing up yeast for a 10 gallon batch of Pilsner this week.  The cell counts I'm getting are lower than what I expect based on both the starter size and the volume of yeast I ended up with.  I know these are both guesstimates, and I was wondering if anyone else had similar experience or if my counts just aren't accurate.

Starter specifics:

- Began with 1 vial of WLP830
- Starters contain 1 g/10ml DME.
- 2 stages: 1.6L for 48 hours, then chilled, decanted, and pitched into 4.4L
- Aerated with pure O2 for 60 seconds, fermented on stir plates at ~ 75dF, breathable foam stopper

I chilled the final starter and the compressed cake at the bottom looks to be 200-250 ml based on rough eyeballing.  According to Jamil's calculator using the "repitching from slurry" tab, this should be about 700 - 900 billion yeast cells even if it has a high amount of non-yeast material (break).  This is the amount that his and the wyeast calculator predicted for me as well.

Problem is, every time I do a count I'm consistently estimating that there are 400 - 500 billion cells in the starter. The starter was still on the stir plate and I didn't see a lot of flocculation.  I took a decent sample from near the middle of the flask using a thief, diluted 10x, and counted.  I can post the specifics of my calculation for a Neubauer-improved hemacytomer when I get home if that would help.

894
The Pub / Re: Something about Tijuana, my city
« on: July 08, 2011, 05:27:10 AM »
Great pictures!  I was just in San Diego for NHC but obviously didn't have enough time for anything other than beer.  Next time I might take a trip down.

895
Cheba: before you dump the beer.... do you have any way of pumping it through a carbon filter?

Isn't that how they make (made) Zima?  :)

896
Kegging and Bottling / Re: Uh-oh... Leaky Keg Blues
« on: July 08, 2011, 05:22:40 AM »
I agree with Tom, banging the lip of the keg with a hammer has helped me fix a keg that wouldn't seal around the lid.

A spray bottle of star san is very helpful for finding leaks.

897
Yeast and Fermentation / Re: Opinions on aeration system
« on: July 07, 2011, 03:55:02 PM »
As for it affecting the flavor profile of the finished beer, like you pointed out it is just one of the things you can manipulate to get the flavor profile you want.

Definitely, as long as you can adjust it in a reproducible way.

I'm just cautiously pointing out that more oxygen may not always be better.  More is different, and for your hefeweizen, more may be worse  :)

898
Yeast and Fermentation / Re: Opinions on aeration system
« on: July 07, 2011, 01:22:57 PM »
As lagers become more of my brewing portfolio, one soon realizes that O2 will get you to the 10-12 ppm often quoted that you need for lager yeast.  Using air you can only get to about 8 ppm.

FWIW, the saturation point at 50°F is ~12 ppm, so if you're chilling before aerating you can also get to the recommended levels for a lager.

Sean,
I'm not disagreeing with you, but I've read elsewhere that "too much oxygenation of the wort can be detrimental to yeast." 
How is this possible if the saturation point at 50°F is ~12 ppm?
Because what you read is technically true but taken out of context.  You can't saturate the wort with enough O2 to harm your yeast.  If you constantly use O2 while growing your yeast you may overwhelm their metabolism and cause damage.  Since we don't constantly pump in O2 it is not an issue.

I don't know...  you can theoretically get to 40+ ppm with pure O2, and I have heard that there's the possibility of oxygen toxicity.  In practice I'd be much more worried about affecting the flavor profile than harming the yeast.  Pitching rate, temperature, and aeration are all factors that affect the flavor of the final beer, and adjusting any one will change the result.  I would be very careful about using too much oxygen in any beer that is supposed to derive a lot of character from the yeast.

899
Yeast and Fermentation / Re: Opinions on aeration system
« on: July 07, 2011, 12:43:09 PM »
As lagers become more of my brewing portfolio, one soon realizes that O2 will get you to the 10-12 ppm often quoted that you need for lager yeast.  Using air you can only get to about 8 ppm.

FWIW, the saturation point at 50°F is ~12 ppm, so if you're chilling before aerating you can also get to the recommended levels for a lager.

Sean,
I'm not disagreeing with you, but I've read elsewhere that "too much oxygenation of the wort can be detrimental to yeast."  
How is this possible if the saturation point at 50°F is ~12 ppm?

That's the saturation point using air, not O2.  He's saying that you can get to 12 ppm using only air if you chill the wort first since the solubility increases.

900
Yeast and Fermentation / Re: Opinions on aeration system
« on: July 07, 2011, 07:44:23 AM »
I'm starting to experiment with pure O2.  I want to see if it has a positive effect on lager fermentations.  My ales are great, but it might save me some time.  I'm not sure I'd switch to O2 for any of my Belgian styles, though. 

I got a welding tank and a low flow medical regulator off of ebay that has the welding CGA-540 fitting (yes, they exist).  I get a lot of foam at 1 LPM, so it seems to me like it's basically a waste of O2.  According to the BYO article that has been posted a few times, you theoretically only need 60 seconds at .2 LPM to hit 8 ppm.

I'm going to do a side by side experiment on a German pils that I'm brewing this weekend.  I'm aiming for 12-15 ppm, so one carboy will get 90 seconds at .25 LPM, and the other 90 seconds at 1 LPM. 

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