? about pitching washed yeast - Home Brew Forums
Home Brew Forums > Home Brewing Beer > Fermentation & Yeast > ? about pitching washed yeast

Reply
 
Thread Tools
Old 04-20-2010, 06:16 AM   #1
lpdb185
Recipes 
 
Sep 2009
Jackson, Mississippi
Posts: 428


i read the sticky and then proceeded to wash the WLP550 from my recent batch of belgian pale ale. i ended up with 2 pint jars that now contain about 1/2" or approximately 35-40ml of yeast slurry. i am about to use this washed yeast in the AHS La Chouffe clone. i believe i read that pitching rates are very important for the taste profile of this style and i want to do this correctly.

mr. malty says i need +/- 295B cells. in the pitch from slurry option, it says i need +/- 90ml of slurry to get 295B cells. so i deduce that there are roughly 100B cells (equivalent to a WLP vial) in 33ml of washed yeast slurry (is this accurate?). so if i was pitching a starter (according to mr. malty), i need a 1.8L starter with 1 vial or 1L with 2 vials. so, am i correct in assuming that i would be close enough to pitching the right amount of yeast if i threw my washed yeast (approximately 75-80ml combined) into a 1L starter? and if pitching rates are so important, wouldn't it matter if the starter was mid-fermentation versus post-fermentation when i pitch into the primary? how do you determine yeast cell reproduction rates for starters?

any input that can guide me in the right direction would be appreciated.



 
Reply With Quote
Old 04-20-2010, 01:47 PM   #2
bknifefight
HBT_SUPPORTER.png
Recipes 
 
Dec 2009
PA
Posts: 1,956
Liked 109 Times on 82 Posts


Well, it's hard to say how many cells you have per ml of slurry. It all comes down to how well it was washed, I guess. If they say 90 ml (~300B cells) is what you need, I am sure that you will be fine with the 75ml in a 1 liter starter. As far as how to determine cell reproduction rates, it varies. Using a stir plate, shaking it and doing nothing will change the reproduction rates greatly. They say it's best to pitch a starter when it is at high krausen but I have done it post fermentation and it was fine.

I'm all over the place with this but hope I answered your questions at least a little bit.



 
Reply With Quote
Old 04-20-2010, 05:57 PM   #3
ksbrain
Recipes 
 
Feb 2007
Mystic, CT
Posts: 1,008
Liked 11 Times on 11 Posts


But if there's enough cells in 90 ml of slurry, then you don't need a starter at all. The starter should grow cells, but it sounds like you have enough cells already.

The trick is that how do you know how dense with yeast your slurry is or what the viability of that yeast is? I just assume that JZ's defaults on the calculator are good enough and go with his numbers.

If it were me, I'd just pitch the 90 ml of yeast you have directly.

 
Reply With Quote
Old 04-20-2010, 07:13 PM   #4
wyzazz
Recipes 
 
Aug 2009
Atwater, OH
Posts: 4,302
Liked 53 Times on 50 Posts


I'd make a starter with a jar what you have and pitch it. If you want your fermentation to take off more quickly then pitch at high krauesen, I however always chill then decant my starters.
__________________
Quote:
Originally Posted by Revvy View Post
And I'd like to see my 1.080 beers ready from grain to glass in a week, and served to me by red-headed twin penthouse pets wearing garter belts and fishnet stockings, with Irish accents, calling me "master luv gun," but we can't always get what we want can we? :)

 
Reply With Quote
Old 04-21-2010, 05:17 AM   #5
lpdb185
Recipes 
 
Sep 2009
Jackson, Mississippi
Posts: 428

so, am i safe to assume that there would be roughly 100B cells per 30ml of washed yeast slurry in the bottom of my jars, or is the pitch from slurry option referring to unwashed yeast?

for those of you that wash and re-use yeast, how do you determine the volume of yeast you pitch into your starter?

 
Reply With Quote
Old 04-21-2010, 05:46 AM   #6
Yankeehillbrewer
Recipes 
 
Dec 2008
Yankee Hill, CA
Posts: 1,541
Liked 28 Times on 28 Posts


How long has your washed yeast been sitting? You can plug in a harvesting date in Mr.Malty and it will give you the percent viability of your washed yeast. After two weeks of sitting you will be down to about 30% viability. I'm not sure what that will do to your numbers, but you should take that into account if you haven't already.
__________________
Kegged: NADA
Bottled: Blackberry Mead
Primary #1:IPA
Primary #2:
Secondary:
On Deck: Pilsener, Brown, Barleywine, Coffee Porter

 
Reply With Quote
Old 04-21-2010, 12:45 PM   #7
dstar26t
If it's worth doing, it's worth overdoing
HBT_SUPPORTER.png
Recipes 
 
Jan 2008
Ridley Park, PA
Posts: 1,152
Liked 56 Times on 41 Posts


Without a microscope and a hemocytometer, it's a huge guessing game. The defaults on Jamil's pitching rate calculator on the pitch from slurry tab represent the average concentration and non-yeast percentage for slurry poured right out of the fermenter and settled for one week in the fridge. It's his calculator and he designed it for his process. If this is not the process you use, you need to adjust the sliders for your particular slurry. You will have less trub so adjust as necessary.
how to use the pitch from slurry tab


__________________
Next: ?
Fermenting: Azacca Oat Pilsner, Egregious-ish, Barrel Fermented Dreg DelcoLambic, Sacch Trois Helles
Drinking: RIS v7, Doppelbock, RIS v6, Carrot Blossom Cedar Mead, Sauerkraut Fermented Gose, Gueuze, Brett Blonde, Kriek, Saison, Sour Blonde
Barrel aged: Rye Barleywine, Tripel, Wee-Heavy


 
Reply With Quote
Reply
Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Pitching Washed Without Yeast Without Starter jmp138 Fermentation & Yeast 12 10-30-2011 06:51 PM
Pitching Washed Yeast For Bottling JeffPhD2005 Bottling/Kegging 1 04-19-2010 12:54 PM
Pitching Washed Yeast mgo737 Recipes/Ingredients 5 03-23-2010 06:01 PM
Pitching washed yeast? palongee1 Fermentation & Yeast 7 02-16-2010 10:23 PM
So, I washed some yeast. Now what? greg75 General Techniques 6 11-11-2006 04:29 PM


Forum Jump