The Great Bottle Opener Giveaway

Home Brew Forums > Home Brewing Beer > Equipment/Sanitation > Colonisation resistance of beer after primary fermentation

Reply
 
LinkBack Thread Tools
Old 11-05-2010, 11:28 PM   #1
Plastered_Marble
Feedback Score: 0 reviews
Recipes 
 
Join Date: Nov 2010
Location: Antwerp, Belgium
Posts: 16
Default Colonisation resistance of beer after primary fermentation

So, I've been wondering about this for a while now.

A lot of people cannot quit stressing how important it is to clean and sanitize everything, to the point where I'm starting to experience their concerns as a phobia rather than rational precautions.

One thing in particular bothers me: the fear of contaminating beer after primary fermentation. At that point, most of the substrate that micro organisms can feed on (simple sugars, organic phosphates) has been depleted, and replaced with alcohol which will kill most contaminants.

If a foreign lifeform where to end up in the beer, survives the alcohol and didn't starve to death, it still has to compete with the yeast still present. Billions upon billions of yeast cells to compete with mere thousands of contaminants. Competing for example for whatever oxygen is present which could go to turning alcohol into acetic acid.

So bottem line: has anyone ever had a contamination after primary fermentation?

__________________

Last edited by Plastered_Marble; 11-08-2010 at 08:53 PM.
Plastered_Marble is offline
 
Reply With Quote Quick reply to this message
Old 11-08-2010, 02:56 PM   #2
Plastered_Marble
Feedback Score: 0 reviews
Recipes 
 
Join Date: Nov 2010
Location: Antwerp, Belgium
Posts: 16
Default

Update:

I've consulted my professor during class on food science, he said that the alcohol levels of beer aren't enough to kill anywhere near all contaminants, and that beer certainly does remain at risk of infection after primary fermentation.

__________________

Io vivat!

Plastered_Marble is offline
 
Reply With Quote Quick reply to this message
Old 11-08-2010, 03:00 PM   #3
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: 40,801
Liked 2707 Times on 1626 Posts
Likes Given: 3483

Default

SO you answered your own question....thread closed.

Actually if you look around here, the overwhelming fear of infection tends to be the purview of new brewers. It's more psychological than anything else.

We had an interesting discussion about this last week....When can I stop worrying about an infection ?

__________________

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 11-08-2010, 05:24 PM   #4
jfr1111
Feedback Score: 0 reviews
Recipes 
 
Join Date: Sep 2010
Location: Quebec, Quebec
Posts: 1,465
Liked 52 Times on 46 Posts
Likes Given: 1

Default

You have to remember that brewing strains were chosen precisely because they would produce consistent and pleasing results: most attenuation rates are in the 68-80%. This means that you have nutrients still available that the sacc can't transform into CO2 and alcohol. Other yeast strains are able to process the residual sugars, thinning the body and stripping the beer of its original taste. Brett is one of the bugs that can accomplish this. But I'd wager that a lot of ambiant wild yeast cannot tolerate the high level of alcohol and the low ph of beer, wich is why you can have the beer in contact with open air during bottling and come out fine. Brett also works very, very slowly, as does pretty much all yeast not specifically bred for brewing.

Does this mean that you should be worried ? Not really. Practice good sanitation procedures at all times and the risk becoems slim to none, with the emphasis on none.

__________________
jfr1111 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
Cheap Primary Fermentation ? BillyVegas Equipment/Sanitation 2 08-04-2010 02:34 PM
Primary Fermentation Help! JUSTINTIMEBREWING Equipment/Sanitation 1 01-28-2010 05:38 PM
Theory concerning primary fermentation abracadabra Equipment/Sanitation 8 03-15-2007 12:35 AM
Primary Fermentation Temp monitoring zoebisch01 Equipment/Sanitation 6 02-27-2007 06:52 PM
Sutable Primary Fermentation Vessels Bsquared Equipment/Sanitation 4 12-04-2006 11:10 PM