Home Brew Forums > Home Brewing Beer > Equipment/Sanitation > Pressure cooker really necessary?
Reply
 
Thread Tools
Old 11-15-2007, 02:37 AM   #1
oooFishy
Feedback Score: 0 reviews
Recipes 
 
Join Date: Mar 2006
Posts: 86
Default Pressure cooker really necessary?

When making starters or a yeast bank, why does everyone get so concerned about sterilization (whooooaa hold on a minute and let me explain). You don't put your carboy in the oven before use to sterile, so why all the extra concern when culturing yeast by themselves? Shouldn't sanitation be sufficient to kill off wild yeast and other bacteria? I mean, this the whole point of iodophor. Will 0.01% of remaining microbes really show up in a culture? Been really trying not to justify unneccesary expenditures. A pressure cooker seems like it may be one of these things...


oooFishy is offline
 
Reply With Quote
Old 11-15-2007, 03:10 AM   #2
Funkenjaeger
Feedback Score: 0 reviews
 
Funkenjaeger's Avatar
Recipes 
 
Join Date: May 2007
Location: Nashua, NH
Posts: 1,637
Liked 9 Times on 7 Posts

Default

It never hurts to be extra sanitary when dealing with culturing yeast for storage. When making starters, chances are you're going to be pitching it within a short period of time and the yeast will out-compete everything anyway, so I don't bother going too overboard sanitizing when making starters.

But if you stick a small amount of yeast in the fridge in a slant or whatever, it's not going to be doing more growing - but other organisms certainly can, especially if it's in there for months. I do my culturing without a pressure cooker because I don't have one, but if I did I would use it.


Funkenjaeger is offline
 
Reply With Quote
Old 11-15-2007, 04:36 AM   #3
malkore
Feedback Score: 0 reviews
 
malkore's Avatar
Recipes 
 
Join Date: Jun 2007
Location: Nebraska
Posts: 6,922
Liked 34 Times on 32 Posts
Likes Given: 9

Default

Sterile is better than sanitized
sanitized is better than clean

plus there are some nasties that are resistent to sanitizers, that would infect our yeast cultures over long periods.
sterilized...they are dead nasties and can't post a threat anymore. basically no room for any mistake...foolproof if you will.
__________________
Malkore
Primary: English Mild
On tap: Pale Ale, Lancelot's Wheat, English Brown Ale, Steam Beer, HoovNuts IPA
Bottled: MOAM, Braggot, Raspberry Melomel, Merlot, Apfelwein, Pyment, Sweet mead, Cabernet
Gal in 2009: 27, Gal in 2010: 34, Gal in 2011: 13, Gal in 2012: 10
malkore is offline
 
Reply With Quote
Old 11-15-2007, 04:56 AM   #4
Iordz
Feedback Score: 0 reviews
Recipes 
 
Join Date: Aug 2007
Location: Phoenix, AZ
Posts: 959
Liked 5 Times on 2 Posts

Default

Proper sterilization ensures that all life has been eliminated and gives yeast best possible chance of successfully growing. Believe it or not that .01% of wild yeast and spores that are not killed by the sanitizer can contaminate a sample. Think about it, you're dealing with very small numbers of yeast when you are culturing. Let’s say you have about 100 yeast cells on a slant and because the slant was not sterilized 10 wild yeast cells get in there. The wild yeast will grow faster than the regular yeast and your sample will turn out contaminated. The yeast need to be one step ahead of the bacteria in all situations, at least until there are strong enough to "fight" off small amounts of foreign yeast.
I would say that sterilization is absolutely critical in culturing, all equipment should be sterile and openings of containers should be flamed whenever possible. You don't have to sterilize, but do want to risk a 5gal batch because the yeast was contaminated?

Iordz is offline
 
Reply With Quote
Old 11-15-2007, 05:57 AM   #5
oooFishy
Feedback Score: 0 reviews
Recipes 
 
Join Date: Mar 2006
Posts: 86
Default

Has anyone actually ever had any contamination issues with a culture with just sanitizing?
oooFishy is offline
 
Reply With Quote
Old 11-15-2007, 01:22 PM   #6
Funkenjaeger
Feedback Score: 0 reviews
 
Funkenjaeger's Avatar
Recipes 
 
Join Date: May 2007
Location: Nashua, NH
Posts: 1,637
Liked 9 Times on 7 Posts

Default

Quote:
Originally Posted by oooFishy
Has anyone actually ever had any contamination issues with a culture with just sanitizing?
I prepare my slants by steaming the filled vials and caps in a steamer basket in a covered pot, long enough for the wort to boil for 10 minutes. Even doing so, I have had one or two blank slants go fuzzy on me after a few months in the fridge, though so far I've been fortunate enough to not have any of my inoculated slants turn south.

It IS a very real concern. since I do not sterilize in a pressure cooker, I always take a close look at inoculated slants before using, to make sure I don't see any obvious nasties.
Funkenjaeger is offline
 
Reply With Quote
Old 11-15-2007, 01:45 PM   #7
mrkristofo
Feedback Score: 0 reviews
 
mrkristofo's Avatar
Recipes 
 
Join Date: Sep 2007
Location: Behind the zion curtain
Posts: 941
Liked 6 Times on 6 Posts

Default

Quote:
Originally Posted by oooFishy
Has anyone actually ever had any contamination issues with a culture with just sanitizing?
I have had bacterial contamination in the lab on yeast/agar plates when the autoclave was down and I sanitized them with bleach/acid. Most unfortunate.
__________________
Coming Soon:
Primary: Stone Vertical Epic 08.08.08
Secondary: Oaked Arrogant Bastard
Conditioning: Dead Guy Ale clone, Double-Dubbel
Drinking: Not for a while
mrkristofo is offline
 
Reply With Quote
Old 11-16-2007, 10:58 PM   #8
Chriso
Broken Robot Brewing Co.
HBT_LIFETIMESUPPORTER.png
Feedback Score: 0 reviews
 
Chriso's Avatar
Recipes 
 
Join Date: Oct 2007
Location: Someplace, Nebraska
Posts: 4,722
Liked 75 Times on 66 Posts
Likes Given: 132

Default

I have not tried this myself yet, as I need to wait for Christmas to get all of my little laboratory goodies for my yeasties, but I have seen others mention before that instead of using a pressure cooker, they instead BAKE any oven-safe pieces at 350F (? or 400F?) for an hour.

More time intensive, yes, but this could be the solution to avoid a 2nd purchase!
__________________
BROKEN ROBOT BREWING CO.

Chriso || BJCP Certified || SMaSH Brewers, Unite! || Nebraska Brewers! || Lincoln Lagers Brew Club
"You have just experienced the paradigm shift that is....all grain brewing." - BierMuncher
Chriso is offline
 
Reply With Quote
Old 11-16-2007, 11:26 PM   #9
mr x
Feedback Score: 0 reviews
Recipes 
 
Join Date: May 2007
Location: Mainly Halifax
Posts: 1,589
Liked 3 Times on 3 Posts

Default

Use your cooker for a steam heated MLT. Get more bang for your buck.
__________________
This place really went to hell. Follow the OF standard stout. Bye.
mr x is offline
 
Reply With Quote
Old 11-16-2007, 11:42 PM   #10
david_42
Feedback Score: 0 reviews
 
david_42's Avatar
Recipes 
 
Join Date: Oct 2005
Location: Willamina & Oak Grove, Oregon, USA
Posts: 25,674
Liked 142 Times on 134 Posts

Default

1. Spores are much tougher than live yeast.
2. When pitching, we use very large amounts of yeast relative to possible levels of contamination.

Dry heat isn't as deadly as steam, but 350F for an hour will kill just about anything.


__________________
Remember one unassailable statistic, as explained by the late, great George Carlin: "Just think of how stupid the average person is, and then realize half of them are even stupider!"

"I would like to die on Mars, just not on impact." Elon Musk
david_42 is offline
 
Reply With Quote
Reply


Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
For Sale - WTB - Pressure Cooker Nickeldeposit For Sale 12 12-18-2009 11:05 AM
pressure cooker bobsstory182 General Techniques 2 04-12-2009 06:14 PM
Cheap 8 qt pressure cooker? Jonnio Brew Stands 7 11-03-2008 03:20 PM
pressure cooker killian Equipment/Sanitation 8 02-22-2008 02:54 PM
pressure cooker? andysat Beginners Beer Brewing Forum 6 09-28-2007 03:41 PM


Forum Jump

Newest Threads

LATEST SPONSOR DEALS