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I'm obsessing over this idea of building a lagering chamber on the cheap. My idea so far is to build an insulated plywood box (or find an old deep freeze) with a homemade temp controller connected to an A/C unit for the cold and a paint can heater for the heat.

Questions:

1. My A/C unit is 10,000 BTU but I'm not convinced it will get the box at the right temp. What do you think?
2. When it's all said and done, would I have been better off financially just getting a used deep freeze and modifying it in a similar way?

Any help is appreciated! Thanks Brewnosers!

I have an under the stairs area quipped with an A/C unit that I use for fermentation. I can get it down to 9 or so degrees in the colder seasons no prob, but not in the summer.

I've used chest freezers and fridges with a temp controller. My best freezer was free and lasted a couple of years before dying. I think you're better off getting a used chest freezer.

Do you think I should go with a working chest freezer or try installing my A/C into a non-functional one?

You could try basing it off of Son of Fermentation Chiller or Mother of All Fermentation Chillers and use the feed from the A/C instead of ice blocks in the cold chamber.

I am hoping to build a 2-chamber unit this summer but will most likely stick with the ice block method (I have yet to brew a lager and have no plans to do so any time soon).

For lagering, I'd say go with a working chest freezer. They're cheap. (At $50-100, you've have a really hard time beating it, even if your labour is worth zero, and you have most of the material lying around.) You'll also have a hard time getting down to near zero with the air con.

Also the air conditioner may switch off before it gets down to the temp you want, assuming you want to cold crash or get near freezing.

Sent from the brew timer.

With lagering, I may need to hold as low as 5C for up to 4 weeks right?

I agree with the freezer idea. It seems to make more logical sense. Also, I'm not super handy so it's less intimidating for me.

So in that case, I'm connecting the cold temp control to the compressor and the heat to a paint can heater? Does that sound right?

That mother of all fermenter chillers is amazing btw. Thanks for sharing!

Approach these days seems to be fermentation in the 50s (strain dependent); temp. rise after fermentation is around 2/3rds complete to ale temps (mid 60s) to help beer clean up diacetyl, etc.; and then stepwise drop down to zero or close to for clarifying. For example: http://brulosophy.com/methods/lager-method/" onclick="window.open(this.href);return false;

I'd skip out entirely on anything handy, if I were you, and grab these off of Dave at Everwood:

1. Thermowell: https://www.everwoodavebrewshop.com/pro ... hermowell/" onclick="window.open(this.href);return false;
2. Controller: https://www.everwoodavebrewshop.com/pro ... ontroller/" onclick="window.open(this.href);return false;
3. Heat wrap: https://www.everwoodavebrewshop.com/pro ... oy-heater/" onclick="window.open(this.href);return false;

#1 isn't technically nec., as most people find that external temps on their carboy are close to measured internal temps, if they put a little bit of foil insulation over the probe and tape it to the carboy wall. Still, it's sexier...

As an aside, depending on how much lager you plan on drinking, I'd be tempted to go with a bar fridge. The ones used for kegerators will fit a carboy if you use a blow off tube instead of an air lock.

Advantages:
1. You can convert it later to a kegerator
2. Better able to handle moisture (freezers aren't designed to be opened and closed all the time, and so condensation in keezers/fermentation chambers is an issue)
3. Less tendency to ice up and drop your temp below what you want it after the compressor turns off (not an issue if you have heating too)

Turned up to max, a fridge will drop close to or at freezing.

This is what I did...fits 2 kegs or 1 carboyhttp://www.brewnosers.org/forums/viewto ... ge#p126611

A/C units aren't really built to get down to lagering temperatures. I've seen a few commercials breweries with CoolBot systems, to override the built-in control. Definitely doesn't fit your "cheap" requirement, but don't be too surprised if your A/C unit doesn't perform as desired.

http://storeitcold.com/index.html" onclick="window.open(this.href);return false;

Thanks for the additional help everyone! I'm making a pils right now. This go around, lagering isn't gonna be a thing.

About that diacetyl rest, at what point in fermentation would you recommend I do that. I'll be at 2 weeks tomorrow.

The diacetyl rest is normally done during active fermentation, once gravity has reached about 2/3rds or more of final. If you brought the temp up now, you'd probably get some renewed activity, but most of your yeast will have gone dormant. The idea is to coax the yeast into metabolizing everything they can before they drop out, so you want to ramp the temp while they're still chugging along. Most of the esters, etc., are produced early in fermentation, during the initial growth stage, so the higher temps should only serve to clean things up, not produce the flavour compounds you might worry about from the ramp to ale temps.

Here's a fast lagering method that a number of people seem to have adopted: http://brulosophy.com/methods/lager-method/" onclick="window.open(this.href);return false;

And here is what Chris White of White labs has to say:

"It is important to provide sufficient maturation time for diacetyl reduction, commonly known as a "diacetyl rest". Diacetyl reduction is slower at colder temperatures, so it is essential to incorporate the diacetyl rest when making cold fermented lagers. The process is simply to raise the fermentation temperature from lager temperatures (50-55F) to 65-68F for a two day period near the close of the fermentation. Usually the diacetyl rest is begun when the beer is 2 to 5 specific gravity points away from the target terminal gravity. The temperature is then lowered to conditioning temperature following diacetyl reduction. For ale production, the fermentation temperature is usually 65-70F, so temperature modification is not necessary. But the fermentation should still be "rested" at this temperature for two days to ensure proper diacetyl reduction. Many brewers make the mistake to quickly crash the fermentation temperature following terminal gravity. Why not? The beer is done, people are thirsty, and there is no taste of diacetyl in the beer. Even though the diacetyl can't be tasted, however, the beer may contain high levels of the precursor, acetolactate, which can be converted to diacetyl. Once the yeast is removed, there is no way to get rid of the diacetyl."