Water bath for fermentation

So I am thinking about using a water bath to try and cut down on temperature variations in my fermenters. It really wouldn't be that hard for me to do, since all of them sit in a bath tub in my unused downstairs bathroom.

Now the thing is, I am not sure if it is something I should add ice to. Right now, my fermenters are at 68 degrees. They can swing up to 72 on some days, depending on how much SWMBO messes with the thermostat.

I am not sure, but I would think that having continuing variations in temp would not be best for the beer, so I figured this would be the easiest way to try and stabilize the temps.

So, for those that have done this before, how submerged should the fermenters be? Half way or 3/4? Or less? And is ice really needed or will cool water do the trick?

You're right about stable temperatures being desireable during fermentation. Cool water will usually be sufficient. I monitor the water temp and if it rises too much I toss a frozen PET bottle in to cool things off. I fill the tubs as much as possible without floating the fermenter. The large volume of water changes temperature very slowly under most circumstances. You could keep the tubs cooler if they were sitting on a concrete floor which can work like a heat sink. Try different sizes and numbers of frozen PET bottles as needed. With a little experience you can keep the temperature pretty close to where you want it and it doesn't require a lot of effort.

I use a water bath for all my beers. The amount of ice needed depends on the temperature of the room where the cooler is located. I use more in the summer and less in the cooler months. The fermentor is also higher in temp during active fermentation than when it starts to wane. I check it every day and either add ice or drain the water in my attempt to keep a consistent temperature.The water is roughly 1/3 to 1/2 the height of the carboy.

My setup:

I use a rubbermaid container in a rectangle shape...I put a couple inches of water in it and a 3/4 gal frozen bottle...
I also use a wet t shirt that sits in the water...It gets the temp down on the first day of fermentation..then I remove the ice...

Well, realistically what you are trying to accomplish is getting the fermentation temps inside the fermenter to be in the 60's nominally, except for Belgians of course. In order to do this you need to have as much of the fermenter submerged as possible. At least as high as the krausen if not higher, in my practice, works best. What I should do is sanitize a probe and dangle it in the headspace to get an accurate temp reading, maybe next time.

Whats the purpose of doing this? To create as little off flavor as possible, or the "hot" alcohols. And everyone knows keeping the temp down does this well. So, you want as much heat to be dissipated as possible so you should have a high thermal mass of water to buffer the exothermic reaction inside the fermenter. Obviously, 2" of water isn't going to help you at all, but having the fermenter as deep as the liquid will help the most. (Any more on the outside than on the inside and it'll float away unless you weight it down)

As for the ice, If you want to begin fermentation in the low 60's and let it slowly rise once active fermentation begins, this is a good way to do it. And its cheaper than building a ferm-chamber. Which is the stage I am at now.

Hope this helps.

I also use the rectangular rubbermaid tubs and water for the lower end of the ale range. My method is just throwing ice in the water but I am going to try frozen water bottles. I haven't tried it with lagers.

Recently, I brewed a couple of Belgians and stuck a heating pad in the tub w/out water to get temps in the mid 80's.

Well, I will just fill the bath tub with water to get the carboys about 1/2 covered or so, and see what that does for me then. I am just trying to improve the quality and taste of the brews, and it seems that fermentation temp can be a part of doing that.

I use a rubbermaid too. I put my freshly brewed hefe in the downstairs closet saturday evening and it was a little high. Sunday morning it was around 70, so I put it in a rubbermaid and added a coupl'a gallons of cold water. It was down to 65 like an hour and a half later, and it's stayed there ever since.

Another thing you guys need to remember is that some of the off flavors come from the period when the yeast begins to reproduce (when not using a liquid starter). Therefore, putting in a rubbermaid/submerging should be what you normally do, not an afterthought when the temp looks like its too high already. The "damage" has already been done.

My first 4 batches were fermented at 70* without the use of a waterbath. All 4 of them tasted the same, hot alcohol, off taste, etc. The batch I started to use ice and waterbath was the first batch of beer that I willingly gave to friends and family without having to preface it with, "its a little green yet". That green-ness would never go away. It wasn't green, it was just HIGH ferment temps lending bad flavors to beers that weren't supposed to have them.

Oh that's a good tip. Thanks RedIroc.

I'm bad about not getting the wort cool enough before I top it off. I always think that when I add the gallon or two of cold water it's going to get it to the right temp, but then it'll invariably end up 4 or 5 degrees higher than I want.