Spike Brewing 12.5 Conical Fermenter Giveaway!

Home Brew Forums > Home Brewing Beer > Fermentation & Yeast > Why don't we agitate during fermentation?

Reply
 
LinkBack Thread Tools
Old 11-01-2009, 02:34 PM   #51
JKoravos
Feedback Score: 0 reviews
Recipes 
 
Join Date: Jul 2009
Location: Chelmsford, MA
Posts: 964
Liked 18 Times on 14 Posts
Likes Given: 3

Default

Another thought I've had for rousing yeast is to run a stainless tube down to the bottom of my fermenter and force some CO2 through the tube once or twice a day to rouse the yeast. It's probably a little easier than constant agitation and it still gets the yeast back up in suspension.

__________________
JKoravos is offline
 
Reply With Quote Quick reply to this message
Old 11-01-2009, 03:24 PM   #52
Bob
Feedback Score: 0 reviews
Recipes 
 
Join Date: Nov 2007
Location: Christiansted, St Croix, USVI, US Virgin Islands
Posts: 3,921
Liked 126 Times on 94 Posts
Likes Given: 36

Default

CO2 agitation works well. It works especially well in conical fermenters - connect the CO2 line to the bottom valve of the cone, set to 20psi (or so), and gently crack the valve. Conical or not, use caution, though, because it has a tendency to foam like crazy.

Bob

__________________

Brewmaster
Fort Christian Brewpub
St Croix, US Virgin Islands

Bob is offline
 
Reply With Quote Quick reply to this message
Old 11-01-2009, 05:55 PM   #53
mordantly
Registered User
Feedback Score: 0 reviews
Recipes 
 
Join Date: May 2008
Location: Westside..... CenCal - the country that'll never take away my guns or money !!!!!!!!!!!!!!!!!!!!!!!
Posts: 3,945
Liked 10 Times on 10 Posts
Likes Given: 1

Default

hrmmmm. easier than groping and shaking my carboys..

__________________
mordantly is offline
 
Reply With Quote Quick reply to this message
Old 11-01-2009, 06:46 PM   #54
Revvy
Post Hoc Ergo Propter Hoc
HBT_LIFETIMESUPPORTER.png
Feedback Score: 0 reviews
 
Revvy's Avatar
Recipes 
 
Join Date: Dec 2007
Location: "Detroitish" Michigan
Posts: 40,804
Liked 2727 Times on 1635 Posts
Likes Given: 3485

Default

Quote:
Originally Posted by mordantly View Post
hrmmmm. easier than groping and shaking my carboys..
Uh, you "grope" your carboys? You pervert you.

You know what's next.....


But remember....

__________________

Like my snazzy new avatar? Get Sons of Zymurgy swag, here, and brew with the best.

Revvy's one of the cool reverends. He has a Harley and a t-shirt that says on the back "If you can read this, the bitch was Raptured. - Madman

I gotta tell ya, just between us girls, that Revvy is HOT. Very tall, gorgeous grey hair and a terrific smile. He's very good looking in person, with a charismatic personality... he drives like a ****ing maniac! - YooperBrew

Revvy is offline
 
Reply With Quote Quick reply to this message
Old 11-01-2009, 08:19 PM   #55
mordantly
Registered User
Feedback Score: 0 reviews
Recipes 
 
Join Date: May 2008
Location: Westside..... CenCal - the country that'll never take away my guns or money !!!!!!!!!!!!!!!!!!!!!!!
Posts: 3,945
Liked 10 Times on 10 Posts
Likes Given: 1

Default

i hug it, kiss it, shake it, whisper sweet tales to it in the night..... how will my beer get pregnant when i swear she wore a rubber? well okay a few of these i do regulary behind closed closets with a carboy. i swirl it and rock it to keep my yeast infection to a maximum.

__________________
mordantly is offline
 
Reply With Quote Quick reply to this message
Old 11-08-2009, 06:06 PM   #56
silverbrewer
Feedback Score: 0 reviews
Recipes 
 
Join Date: Apr 2009
Location: Birmingham UK
Posts: 171
Liked 1 Times on 1 Posts

Default

I am reading this post as I was thinking of very gently continuosly stiring my fermenter so the internal cooling coils would have the wort passing over them.
Are you lot in agreement that the yeast action causes enough currents within the fermenter to make a stirrer redundant?

__________________

Blessed are the "cracked", for it is they who let in the light.

silverbrewer is offline
 
Reply With Quote Quick reply to this message
Old 11-08-2009, 06:26 PM   #57
JesseRC
Feedback Score: 0 reviews
Recipes 
 
Join Date: Oct 2008
Location: San Antonio
Posts: 1,784
Liked 10 Times on 9 Posts
Likes Given: 1

Default

I swirls mine , gentle shake after the most of the fermentation is over with. It helps clean the sides off and rouses the yeast just before I up the fermenter up to 68-69F. I dont do this during the 1st 5 days cus fermentation is already going strong. I consider my fermenters closed systems and I dont think the beer is getting oxidized. What does it buy me, well probably nothing if I just let is sit long enough, but on a dry light ale , its just peace of mind that it gone as far as it can go . On stouts I hardly ever swirl, as I want them a little sweet.

__________________

Jesse

Primaries: Mojave Red (AG)
Kegs: Hibiscus Saison (AG), Orange Kolsch (AG) , Cocunut Porter
Future Brew: Wee Heavy

JesseRC is offline
 
Reply With Quote Quick reply to this message
Old 11-08-2009, 08:00 PM   #58
JVD_X
HBT_LIFETIMESUPPORTER.png
Feedback Score: 4 reviews
 
JVD_X's Avatar
Recipes 
 
Join Date: Jan 2008
Location: Gainesville, Virginia
Posts: 1,492
Liked 3 Times on 3 Posts

Default

Quote:
Originally Posted by JKoravos View Post
I've been thinking of adding agitation to my next fermenter. I don't see any reason that it would have anything other than a positive affect on the fermentation. The agitation doesn't need to be terribly vigorous and probably not even continuous to get maximum attenuation out of the yeast. You'd likely have to adjust your brewing process a bit for slightly higher attenuation, but in the long run it's probably an extremely consistent fermentation method.

Oxidation shouldn't be a concern at all. I'm not sure why it would be, there's no oxygen in there.
You could pressurize o2 into a keg then wait for high krausen and put the keg under vacuum. Just a crazy idea I suppose
__________________

- JVD_X

JVD_X is offline
 
Reply With Quote Quick reply to this message
Old 11-08-2009, 10:42 PM   #59
Hermit
Feedback Score: 0 reviews
Recipes 
 
Join Date: Nov 2009
Location: Alternate Universe
Posts: 2,226
Liked 61 Times on 55 Posts
Likes Given: 10

Default Interesting.

Quote:
Originally Posted by Bonysplicer View Post
Your statement shows a lack of understanding of physical chemistry. Check out references to Henry's Law. In any fermenter situation, carboy or otherwise, gases exist in equilibrium between two phases, gaseous (headspace) and dissolved gas in solution. the rate of transfer in this equilibrium is a surface area limited function.

For example, when you use an oxygen stone or fish tank bubbler to pump o2 through your wort, the wort picks us a high level of o2 quickly due to surface area to volume ratios of tiny bubbles and the high partial pressure of o2. Similarly, boiled, degased starter wort picks up oxygen because whirlpool agitation increases surface area exposure, but still the wort will only dissolve enough o2 gas to be in equilibrium with the partial pressure of o2 in the headspace. So relative to the gas/liquid interface stirring merely hastens the balance of equilibrium.

BUT in a fermenter yeast use o2 and "fart out" co2 into solution So the partial pressure of dissolved o2 decreases over time and the partial pressure of co2 increases over time. Additionally, the total pressure in the headspace is regulated by the airlock/blow off. So as the co2 builds up in solution it increases the partial pressure of gaseous co2 (equilibrium). But since the total pressure is fixed, gas is driven off through the airlock. That gas is a mixture of co2 and o2. Over time the faction o2 in the headspace limits toward zero through being driven off through airlock and being used by the yeast.

My understanding is that "oxidation flavors" are caused by excess dissolved o2. From this it would seem prudent to drive off excess dissolved oxygen as quickly as possible, prehaps through agitation in an oxygen defficient environment.
I just racked for the first time last night and was surprised by the amount of gas that came out. I thought it had reinvigorated the yeast but I'm told it was probably just excess CO2 coming out of solution. There was still some activity this morning, which might be fermentation but wouldn't getting the CO2 out be beneficial also?
__________________
Hermit is offline
 
Reply With Quote Quick reply to this message
Old 11-09-2009, 11:59 PM   #60
corncob
Feedback Score: 0 reviews
Recipes 
 
Join Date: Mar 2009
Location: Columbia, SC
Posts: 139
Liked 1 Times on 1 Posts

Default Funny this should come up...

Maybe I am naive about what I read on the internet, but I have been trying to brew something remotely close to Samuel Smith's Organic Pale Ale since I first started brewing. I read this:

http://www.merchantduvin.com/pages/5_breweries/samsmith_yorkshire.html

I bought four vials of WLP037 Yorkshire Square Ale Yeast. I have a batch of 1.045 bitter w/ fuggles and goldings in the closet at 65*.

And I've been swirling it something awful twice a day since the bubbles started. I'll let you all know in a few weeks. Ahhhhhh science!

__________________
corncob is offline
 
Reply With Quote Quick reply to this message
Reply


Quick Reply
Message:
Options
Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Wine fermentation vs beer fermentation Tophe Wine Making Forum 4 11-19-2010 06:38 PM
Which is better? A fast, very active fermentation, or a slow steady fermentation? cerberus9 Beginners Beer Brewing Forum 6 09-24-2009 04:56 PM
Fermentation cooler vs refrigerator vs son of fermentation Belmont General Techniques 14 04-10-2009 12:43 PM
Stuck fermentation...finished fermentation...? arover Beginners Beer Brewing Forum 3 04-08-2009 03:05 AM
Should I agitate the bottles? alee Beginners Beer Brewing Forum 13 02-12-2009 10:51 PM