Temperature fluxing in my fermenter, issues?

[gregiscool]

I have my carboy sitting in a big rubber container filled with water that each morning and evening i put a 2 liter frozen bottle in to cool it down. By the time i get home from work, the one i put in there that morning is just water inside the bottle and my water temp(the water my carboy is sitting in) is just below room temp(which is about 77, hence y im trying to keep it as cool as possible). Is this going to create issues having my temp go from 65 or so(the first hour or 2 with the frozen water bottle in it) then rising to 76 or so as it melts through out the day? The temp change is not fast my any means, but daily it rides from colder to hotter and back to cold as i replace the frozen water bottles. Will this be bad for my yeast, or is the change so small and so slow it wont matter? The yeast package says to go between 65-75 as ideal, but figured id ask you guys! heres a pic of my baby in the bath

 

[EuBrew]

To keep things a little more constant from a temp standpoint you could throw an old wet t-shirt over the carboy and put a fan blowing on it. This will lower the temp a couple degrees. You could get some off flavors getting in the high 70's but it's not much out of the range of your yeast so you're probably alright. Do a search for regulating fermentation temps or check out the stickies in the fermentation forum for more ideas.

Also if you are just monitoring room temp your wort is probably quite a bit higher than that during active fermentation. Get some sticky thermometers for the side of your carboy so you'll have a better grasp on what temp your fermentation really is. If you are just reading room temp, or even that of your water bath not the carboy, then you are likely going to be in the 80's for fermentation temp which will likely lead to some funky flavors. Having said that, it will be drinkable. Probably not your best batch, but RDWHAHB.

 

[MetallHed]

I had the same problem with you with my setup (basically same as yours too)

I was doing a weissbier and Im pretty sure it fermented too high because there are noticable banana flavors.

I now am finishing a mother of fermentation chiller before I brew again. I would suggest making one of those or find a cheap freezer or fridge on craigslist and buying a johnson controller to control the temps.. thats' probably the best way, I just like making things harder and want a cabinet I can display at my house.

 

[deezy]

+1 to the Tshirt idea, here's kind of what I'm doing now (note- I pulled back the tee to get a picture normally I overlap the tshirt over the carboy but not covering the sticky thermo...if it gets wet it will screw it up. I'm using smaller water bottles but have to keep a 6 frozen bottle rotation twice a day to keep temps 65-66*:

I'm looking for a freezer now that I've picked up a temp controller to begin fermenting in so no more bottle swaps but this has done me well so far.

 

[PorterIV]

Eubrew raises an important point regarding reading ferm temperatures. It took me a while to realize how much higher the actual temperature of the wort is compared to the air during fermentation. Those yeasties throw off some heat while they are doing all that work! The sticky thermometers are great, once you get a fridge set up though go to the thermowell with a probe on the digital controller. It is awesome.

 

[Yooper]

I can't tell in the picture- how much water do you have in the water bath? If you fill it up to the level of the beer, you'll have much less in the way of temperature fluctuations. Water is a great insulator, and it'll take a LONG time for 5 gallons of beer and 5 gallons of water to change temperature.

 

[gregiscool]

I can't tell in the picture- how much water do you have in the water bath? If you fill it up to the level of the beer, you'll have much less in the way of temperature fluctuations. Water is a great insulator, and it'll take a LONG time for 5 gallons of beer and 5 gallons of water to change temperature.

its filled almost all the way to the beer level, , maybe 5-6 inches short. I figured the water would hold a cooler temp better then air, and be harder for the carboy to heat it up. now i got a solid 2 liter bottle rotation going, 1 frozen in the morning at 9am, take that out at 8pm, put in another frozen bottle then till 9am the next morning and repeat.