Simple lager temp control

hi, i'm looking to make an oktoberfest but don't have the fancy temp control options for the fermentation (lagering itself is not a problem) so i'm probably going to go the "fermentor in a big bucket full of water and ice" route. but i had a quick question - what temp should i be looking for for that water? our tap water is pretty cold, probably less than 50, so should i be looking to get it colder with ice to make the actual fermentation temp around 50?

Well, it depends on ambient temperature, too. My basement is right around 50 now, so I fermented it in primary just fine down there. Then, I brought it upstairs (63 degrees) for the diacetyl rest and then racked it. Then, for the lagering, I put the cold water in the cooler and let it come up to 50 degrees and added the carboy. Then, each day, I added a frozen water bottle (changing out the thawed ones) until I was at 34 degrees. Then all I had to do was change the frozen water bottles every three days or so. If you attempt this in a warmer room, of course you may have to do things a bit differently.

If you look in my gallery, there are pictures of my "Yooper Lagerator". It's a simple wheeled igloo cooler with a new lid I made out of styrofoam so the airlock can poke out. If you're not using a cooler, you'll have to insulate it a different way.

Gosh, I just have to guess a bit it at this, but I would imagine 50F water would be just fine. Water is a better heat conductor than water, and it has a much higher specific heat. A fermentation temperature from 50-55 should work fine for whatever lager yeast you choose.

The real trick with lagers is holding a stable temperature. You need to figure out how to maintain that temperature. Are you going to insulate everything, switch out the water so often, add ice, etc? I'm afraid I cannot help you with that, but I hope someone will chime in who can.

Edit: Hooray! Yoop to the rescue!


TL

the first lager i made was fermented in jan in the basement and it was 50-55F the whole time - perfect. i didn't know what a diacetyl rest was at the time, i just racked to secondary and stuffed it straight in the spare fridge (about 35-40F). very scientific. it worked out ok and but tastes like an american amber lager, although it was supposed to be a recipe for a munich helles! (provided by the LHBS)

the next cooler i buy is for use as an AG MLT so I'll just use the big bucket full of cold water w/ a wet towel draped over it approach. i'm thinking if i can keep the water at 45F the wort inside will be a bit warmer? or should i look to keep the water itself at 50F?

TexLaw said:

The real trick with lagers is holding a stable temperature. You need to figure out how to maintain that temperature. Are you going to insulate everything, switch out the water so often, add ice, etc? I'm afraid I cannot help you with that, but I hope someone will chime in who can.

Click to expand...

i could swap stuff out every couple of days - i've got some business travel coming up so can't monitor on a daily basis. i should have done this when the basement was cold enough - maybe i should just bail on it until either i get better temp control options or it gets nice and cold again!

As Tex said, water is a good insulator, and the water in the cooler/tub will be the same as the water inside the carboy. I keep a floating thermometer in that water, and check the temperature that way from day to day. Remember, what you want is a constant temperature and not fluctuations. So, you really should have something insulated, like a big tub with blankets or sleeping bags over it. Still, if you have a tub full of water, it does take a long time to change the temperature of that much volume. So, once you get it to say, 50, then it should stay there fairly easily.

thanks guys. this really has to be the best forum on the whole wide internet.

cd:

It's good to see that you're still plugging away. Seems like you've come along ways since we met in Nov.

It took me over a decade to do my first lager!

You can tape some sheets of foam insulation together and make a quick stable enviroment for the lager. I would still put it in a bath so you can add ice or heated water if it fluctuates too much. 1 inch foam makes a huge difference in temperature stability though.

I made Yooper's Lagerator (with some minor modifications) 'cause I didn't want a 5th fridge & I've been spending way too much $$$ on brewing stuff lately. I think I spent a total of $30 and it's been working really well in my 63° basement. I add 2qts of ice every other day and it stays right around 53°.