Swamp cooler TOO cold!

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barleyboy

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Well I finally decided to try to control my fermentation temps with a swamp cooler. The other day I brewed a pale ale with US-05 and put 'er in the cooler. I've been switching out 1/2 gallon ice jugs every 12 hours. I checked the temp about 2 hours after the last switch and it is running at 55 degrees! What are the consequences of fermenting US-05 at these temps? Am I stressing the yeast too much? Am I going to get off-flavors? Thanks!
 
more like it'll be very dormant and will just take a long time to ferment. warm it up a little, let it ferment faster, and it'll be fine
 
In theory US-05 will ferment, albeit more slowly, at 55F. There was an article about this in zymurgy a few months back as I recall. My biggest worry there is that you started fermenting at a much higher temp, and then dropped the temp suddenly. The yeast can react poorly in that specific situation. That being said, let it warm up a bit and maybe gently shake the fermenter, and you ought to be fine.

Why are you switching out ice jugs without checking the temp first? I use the same method, but I always check the water temp in my swamp cooler before I make any decisions to swap out.
 
What's the ambient temp you're doing your swamp cooler? If it's 70 or less, stop adding ice and let it sit in the water and let that act as the heat sink.

I'm not sure on the implications of too low temp on US-05, but I'm thinking it's more of just inhibition and not going to cause off-flavors. They'll be a little sluggish, but if you heat it up I'm guessing that'll cover all that up.
 
Just to clarify, I actually have been checking temps all along. They just never dropped below 59 until today, which I've read is the low end of the range for 05. Ferm temps started at 60-61, so i didnt drop a huge amount from that. Ambient room temp is 69-70. When it's near the 12 hour switch, temps get to 64-65. Air lock is bubbling away, so my guess is they are fermenting ok, just didn't know if I was stressing out the yeast and they would produce off flavors or is the worst thing would be slow fermentation.
 
My question is if you are checking temps, why do you keep swapping bottles?

The whole point of using that setup is to maintain a particular temperature, not to let it go lower and lower. Only swap bottles when the temp is starting to get to the upper end of the range you are trying to maintain. I usually go low-mid 60's for US-05, but high 50's works OK, too.
 
Well I was swapping them when it got to mid 60s. Apparently that's too early?
 
How does it keep getting lower if you are letting it get to the same temp before swapping it? The only possible answers are that you are swapping in way more ice than necessary (in increasing amounts) or something is wrong with your measurements.


Let's say you let it get to 65F, so you swap out a new bottle. So then 12 hours go by, and the temperature is down to 55F?
 
I'm not an idiot. I know how to measure temps. My question was about the yeast. Not the temps.
 
55 is low for this strain. It has been reported that it can give of a "peachy flavor" below 64deg. As long as its still fermenting and you can warm it back up you will be fine. Its not the best for the yeast but better then fermenting too hot.
 
I just finished a nut brown fermented with US05 at cold temps. I was shooting for 60-62 degrees but most of my fermentation ended up at 57-58 degrees. It slows down below 60 degrees but still finished out nicely. Try to get the temps up a little, low 60's it runs pretty good.

-Tony
 
I use 2*20 oz plastic pop bottles. I also have a few 12oz water bottles. This helps me really dial in temps, for me I see that one day 2,3&4 after pitching are the "hottest" temp days.

FWIW:
 
I'm not an idiot. I know how to measure temps. My question was about the yeast. Not the temps.

Look, I am trying to help you out here, and part of the troubleshooting process is eliminating variables. I already told you what I think about the yeast, but thought it would be worth looking into your temperature control situation because having the temp go from 65 to 55 and back again several times is DEFINITELY not good for the yeast.

I've only been using this method successfully for a few years, but you go ahead and do whatever you want. Apparently you already know how to control temps in your swamp cooler to within a couple of degrees.
 
I think you’re overreacting a bit. You’ve got, what, 50 pounds of wort and carboy in ten or twenty pounds of water? So with a ten degree swing I’m guessing the wort will swing about three degrees.

Just a guess, I don’t feel like setting up a differential equation. Looking at it another way you have 2L of ice going into 19L of wort. If the ice is at 30 and the wort is at 60, that’s 30 degrees difference. Since the mass you’re cooling is ten times bigger than the ice, that makes a difference in the carboy of 3 degrees.

Which fortunately agrees with my previous WAG. Those are rough calculations but it puts you in the ballpark. You’re looking at a few degrees over a twelve hour period.

You could use smaller bottles more often, but who has the time? Better to have a small temperature swing than to ferment hot.

Slainte
 
weirdboy said:
Look, I am trying to help you out here, and part of the troubleshooting process is eliminating variables. I already told you what I think about the yeast, but thought it would be worth looking into your temperature control situation because having the temp go from 65 to 55 and back again several times is DEFINITELY not good for the yeast.

I've only been using this method successfully for a few years, but you go ahead and do whatever you want. Apparently you already know how to control temps in your swamp cooler to within a couple of degrees.

I know you were trying to help out. And I appreciate that. I appreciate everyone's help and comments here, I wouldn't be where I'm at with my brewing without this forum. But some of your comments seemed to imply that I am of less than average intelligence or even outright dumb. They are basic physics concepts. I didn't start this thread with the intention of offending someone that was offering advice. So, I guess I'm trying to say sorry. And thanks. At the same time.

And thanks to all for your comments and advice!
 
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