Coldbreak Brewing Giveaway - Open to All!

Home Brew Forums > Home Brewing Beer > Fermentation & Yeast > Fermentation...air temp or wort temp?
Reply
 
Thread Tools
Old 07-04-2013, 03:41 AM   #1
rdbrett
Feedback Score: 0 reviews
Recipes 
 
Join Date: Nov 2012
Posts: 211
Liked 2 Times on 2 Posts
Likes Given: 3

Default Fermentation...air temp or wort temp?

I do not have a temp controller. To ferment at cooler temps, I have to put in a cooler on basement floor, sometimes using ice bottles. In general, when i read in recipes the fermentation temperatures, is it referring to air temp or wort temp? I'm a rookie, I've always assumed it was air temp.
But, when reading other threads about swamp coolers I have my doubts. Getting ready to brew a batch that says to ferment in lower 60's. just wanted to check and make sure I understood.


rdbrett is offline
 
Reply With Quote
Old 07-04-2013, 03:47 AM   #2
kh54s10
HBT_SUPPORTER.png
Feedback Score: 0 reviews
 
kh54s10's Avatar
Recipes 
 
Join Date: Aug 2011
Location: Tiverton, Rhode Island
Posts: 7,995
Liked 875 Times on 729 Posts
Likes Given: 231

Default

Yes, your assumption was wrong. You need to control the temperature of the wort. When fermentation occurs it creates extra heat. If you do a swamp cooler you will have to change ice bottles more frequently at first.

Get a large plastic tub and 6-10 inches of water. If you use a stick on strip thermometer you do not want to submerge it. Rotate ice bottles to keep the wort temperature in the low to mid sixties and keep the temperature as stable as possible.


kh54s10 is offline
 
Reply With Quote
Old 07-04-2013, 03:52 AM   #3
BigFloyd
Feedback Score: 0 reviews
Recipes 
 
Join Date: Dec 2012
Location: Tyler, Texas
Posts: 5,163
Liked 720 Times on 627 Posts
Likes Given: 630

Default

The wort temp is what matters.

Hope you are successful keeping yours cool.
__________________
Good Temp Control -----> Happy Yeast ------> Tasty Brew
BigFloyd is offline
 
Reply With Quote
Old 07-04-2013, 04:16 AM   #4
rdbrett
Feedback Score: 0 reviews
Recipes 
 
Join Date: Nov 2012
Posts: 211
Liked 2 Times on 2 Posts
Likes Given: 3

Default

I dont have a strip thermometer on my fermentor. My recipe calls for fermentation temps in the lower 60's. So, I assume I'll need to keep the swamp water in the upper 50s? Need to get a thermo on my fermo!!
rdbrett is offline
 
Reply With Quote
Old 07-04-2013, 04:32 AM   #5
rdbrett
Feedback Score: 0 reviews
Recipes 
 
Join Date: Nov 2012
Posts: 211
Liked 2 Times on 2 Posts
Likes Given: 3

Default

Thanks for the help!! I need to get a thermometer to stick on my fermometer!
rdbrett is offline
 
Reply With Quote
Old 07-04-2013, 05:12 AM   #6
CryoEng
Feedback Score: 0 reviews
Recipes 
 
Join Date: Mar 2012
Location: Rio Rico, AZ
Posts: 95
Liked 12 Times on 4 Posts
Likes Given: 2

Default

Right concepts, but the process may be flawed.

Who thinks a strip of plastic ("Fermometer") stuck on the outside of a glass vessel can represent the temperature of the contents of the vessel better than it represents the temperature of the air around it?

Got to couple the sensor to the thing you want to know the temperature of. The wort.

A piece of tape on the outside of the glass carboy is much likely to be closer to the surrounding air temp than the wort inside the vessel.

Don't want to burst bubbles, but if you think about the heat sources, sinks and paths, this isn't that hard.

Cheers!
CryoEng is offline
 
Reply With Quote
Old 07-04-2013, 01:51 PM   #7
BigFloyd
Feedback Score: 0 reviews
Recipes 
 
Join Date: Dec 2012
Location: Tyler, Texas
Posts: 5,163
Liked 720 Times on 627 Posts
Likes Given: 630

Default

Quote:
Originally Posted by CryoEng View Post
Right concepts, but the process may be flawed.

Who thinks a strip of plastic ("Fermometer") stuck on the outside of a glass vessel can represent the temperature of the contents of the vessel better than it represents the temperature of the air around it?

Got to couple the sensor to the thing you want to know the temperature of. The wort.

A piece of tape on the outside of the glass carboy is much likely to be closer to the surrounding air temp than the wort inside the vessel.

Don't want to burst bubbles, but if you think about the heat sources, sinks and paths, this isn't that hard.

Cheers!
Good point. There's a difference (small as it may be) in using a sensor taped to the bucket and insulated vs. one of those strip thermometers. I suspect that the strip (which I haven't used) would give you a fairly good reading on the vessel temp, but could be influenced somewhat by the air temp.

For the thread starter, if you can keep the water in the tub about 60-62*F for the first 4-5 days and then let it rise after that into the middle 60's to finish, you should be golden. Having it in a tub of water creates a large heat sink which influences the fermenter temp more than air will.
__________________
Good Temp Control -----> Happy Yeast ------> Tasty Brew
BigFloyd is offline
 
Reply With Quote
Old 07-04-2013, 02:03 PM   #8
rdbrett
Feedback Score: 0 reviews
Recipes 
 
Join Date: Nov 2012
Posts: 211
Liked 2 Times on 2 Posts
Likes Given: 3

Default

Will that give me a wort temp of of mid to low 60's or so I need to get water temp lower in upper 50s in order to drop wort temp to lower 60s? Thx
rdbrett is offline
 
Reply With Quote
Old 07-04-2013, 02:41 PM   #9
Wynne-R
Feedback Score: 0 reviews
Recipes 
 
Join Date: Aug 2009
Location: Texas
Posts: 944
Liked 111 Times on 72 Posts
Likes Given: 92

Default

I use water to cool my fermentor. My set-up has the water level even with the beer. Even with the most violent fermentation the temperature difference is about 1.7° F. One degree is more typical for high krausen, winding down to zero as the fermentation finishes.

Don’t worry about the accuracy of the LCD strip, they’re pretty good, just don’t get it wet. You can read them to about a degree Fahrenheit. The conductivity of the water is about twenty times that of air. The temperature difference between the air and the beer is a few degrees at most, sitting in water. The air temperature won’t significantly affect the reading.


Wynne-R is offline
 
Reply With Quote
Reply


Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Fermentation longevity and wort temp question new_to_Breweing Beginners Beer Brewing Forum 3 02-20-2012 05:26 AM
Fermentation Temp - Ambient or Wort Temp? TheZymurgist Fermentation & Yeast 1 11-01-2011 02:43 PM
fermentation temp vs. wort temp zodiak3000 Beginners Beer Brewing Forum 3 08-11-2011 05:17 PM
carbonation calculator: fermentation temp, cold crash temp, bottling temp? jigidyjim Beginners Beer Brewing Forum 8 11-27-2010 01:04 AM
Immerse temp probe in wort during fermentation? eddie884 Fermenters 6 10-11-2009 12:56 PM


Forum Jump

Newest Threads

LATEST SPONSOR DEALS