Heat!

I am keeping my fermenter in my garage, which is kinda below ground level and somewhat cool, but with the temp rising, the fermometer attached to the plastic tub, indicates a temp of 76-78F!!

What can i do to bring it down and keep it that way?

I haven't had the need to try this yet, but I've read a few recommendations of putting a wet towel around your fermenter and keeping it in a tub or trash can, allowing the towel to pull more water from the container to maintain your water insulation/cooler.

The cooler filled with water works well for a simple solution. Use a towel like cormi3r recommends and make sure it sits in the water as it's draped over and around the fermenter (unless it's a bucket, then just make sure it's around). This will pull water up from the cooler and allow for evaporation which will in turn cause a transfer of heat and lower your temp a little bit. If you want to make it even more effective, plug in a fan and point it at the cooler/fermenter. Good luck.

i have read about keeping it in a bathtub filled with water. what temp water should u use for that?

I'd use a temperature on the low end of your target temperature range. That way you've got a few degrees of range to allow for the water to get warmed up a bit. Also, if you're water (heatsink) is the temperature you're shooting for (low end), than the fermenter will only ever reach that low temperature, hence happy yeast.

The towel is a good idea, but I have had better success with an old tshirt. Every time I used a towel, I was either not able to get it to go all the way around, or it would fall off etc etc. When I use a tshirt I just put it on the bucket/Carboy and put the airlock through the neckhole. That way it never falls off and wraps all the way around the fermenter. I would make the water pretty cold. Coldest setting on your water and I would even consider putting a couple bottles of frozen water in there. I think you could easily drop your fermenting temp 10-15 degrees doing that.

Thanks for the t-shirt tip. I will try that.

I currently have a Dortmunder batch going in the primary. Bubbling like crazy since Sunday night and finally slowed down significantly last night. Problem is, it started fermenting at around 75 degrees. By tuesday night it was around 79-81 degrees. Fermentation is getting close to done so it might be a little late to cool this one down any.

so what do you think? Am I going to have a batch of headache formula and off-flavors?

I keep mine in a bucket filled with water and put that whole thing in the bathtub. Keeps at about 68-69 and i keep the house around 74-75

The wet towel technique works very well if you have a fan blowing air across it. I can lower my fermentation temperature by 5-7˚F doing this.

CAUTION, if you try the bucket of water technique in areas of high humidity, the only thing you'll get is mold. ha ha.

I tried this a few weeks back, even put sanitizer in the water and sure enough, it had weird fuzzies growing on the outside of the carboys and bottles. gross.

If you do this, dont put it in a closet or other dark area.

I do the bathtub with about 5" or water in it and a fan running on the water all the time for the evap cooling. Sometimes I'll add in some chilled fridge water after some evap. Seems to work like a champ.

Get a heavy duty cardboard box big enough to fit over your carboy with some extra space. Put a couple large containers of ice it there next to the carboy. (Put some more water in the freezer so you can swap out as necessary). Drop a heavy blanket or sleeping bag over the box. A couple half gallon containers of ice will keep it cool for at least 12 hours. Add more ice as necessary.