Fermentation Temp Control Question

In a freezer you really only need a single stage controller. Set the temp you want and the compressor will come on until it gets there, then it will go off until the temp rises again.

 

Since my freezer is in a room that gets below 64*F, during the start of fermentation I need a heater. But I just warm the inside of the chamber with a reptile light bulb. It's on a dimmer set to low and I crack the lid open.

For when I want to drive the temp up, lets say for a saison or to finish out fermentation, when I know that the yeast won't drive the temp I switch the controller to heating and plug in the light bulb to the controller.

But to answer your question, the set up that you have should work. But one problem is that with a freezer once it kicks off it can still drop the temp another few degrees. You would have to make sure not to set your warming setting above that spot. You don't want the constant fight between hot and cold. That's what I like about my set up, I can maintain a tight window. I think at that helps especially helps to keep the English yeasts from dropping out too soon. Also condensation is a PITA with most freezers. The bulb helps to dry out the compartment.

You could always get that controller and fine tune your heating approach later.

 

Sorry, but I don't know. I don't have your system. It's something that you'd have to test.

Like many things in brewing everyone needs to decide how much reward they get for all of the fart'n around that they do. Personally, I probably micro-manage. Is there a pay off? Not sure. But just so you know I'm not trying to talk you out of the two stage controller for the single stage.

I know that I had to learn my set-up. For instance when I do a big beer there is a point where the extra cooling effect of the freezer is much less of a factor. I just like how with my light bulb I have the ambient temp as a constant.

 

I use the Johnson temp controller which is cheaper than that ranco dual stage and can be put in a heating and or cooling mode. I have a cold basement where I heat with a space heater for ales and use my fridge and cooling mode or lagers. The Controller could be hooked up to the fermrap also if you need heating mode. The Johnson just can't cool and heat at the same time like the ranco can. http://www.northernbrewer.com/shop/...on-controls-a419-digital-temp-controller.html
I also just tape the temp probe to my fermenter and put some insulation over and make sure I don't point my heater at it but for maximum control/accuracy a thermowell is a nice investment
http://morebeer.com/view_product/16672

 

I haven't noticed my freezer being anything but a very constant temperature with my Johnson controller, tho I'm sure there could be some fluctuations due to thermal inertia.

Condensation is a problem tho, I have to clean the thing out with some bleach water every now and then to make sure it doesn't get moldy.

 

That particular thermowell doesn't work with the Johnson controller I just noticed.

 

I've found at that damp-rid helps some.

 

If your temp is 60 in the basement the actual fermentation temp will be around 65-68F, at least during the most active stage. If I had a basement like that I wouldn't even worry about a freezer in the winter. If you're worried about getting it too cold just hook up the heater and use it. I think you may have to move a jumper to put it into heat mode, but that's a lot cheaper and simpler than the 2 stage.
I say this because I have the 2 stage temp controller and in 4 years I've used both stages exactly once. My garage is either way too hot or way too cold, never anything like what you describe in your basement.

 

I have two of the Ranco single stage controllers and they work well. As others have said, it is unlikely you will have the need for heat and cold on the same day. Remember, the single stage can be set to either heat or cold and there is no need to re-wire, just re-program the settings. The single stage gives you the flexibility to control a freezer or ferm-wrap (just not both at the same time).


So if I want to ferment at 68 degrees I would set the cooling to 70 and the warming to 66?

I would not recommend this, extreme precise temp control is not required. To prevent short cycling the compressor I program a 4-6 degree temp differential (I'm in cool mode only). Then use a thermometer in a bottle of water to check things. With this 4-6 temp spread the thermometer does not move even one degree. Your 5 gallons of brew will move even slower. You want to ignore the swings in air temps in your freezer, it's the temp of liquid you are after. It would be nice to have a thermowell, but taping the probe to your bucket and covering with bubble wrap is an easy work-around.

You can also find this controller on ebay. The single stage model is the ETC-111000 which runs about 50 bucks. It requires wiring, but it's so simple a caveman can do it.

 

The thing to keep in mind is that you are trying to control the temperature of the liquid, not the temperature of the air.

5 gallons of liquid actually has a very large thermal mass, so it is not going to be fluctuating very quickly at all. Additionally, the yeast activity is going to produce it's own heat. So if you have a consistent 60 degree environment, your heater may only need to turn on a couple times a day. It's definitely unlikely that you need dual-stage control.

I'm in the opposite position where my environment is warmer than I need it to be, so even though I have a two-stage controller (cheap Chinese ETC with homemade wiring), I only ever use the cool side. With the thermometer probe taped to the side of the fermenter, it only comes on 2-3 times a day in the winter, and that's with a 1 degree tolerance (I really only need it in the summer).

The only reason I wanted the two-stage is so I can use it for generating sour cultures (and the DIY controller is cheap).

Anyway, the tldr summary is that what you are looking at will definitely work, but it might be overkill. If you really use dual-stage control, you need to be sure you set it up so your freezer and heater don't fight each other.

 

I brew almost exclusively lagers and have a very similar setup in my chest freezer. In short, this was the best purchase I've ever made. I set with a 2-degree temp differential either way and can hold at a steady 62 ambient for my Koelsch for all of primary, even in the winter. For secondary it is easy to drop the temps by 2 degrees or so each day to complete the lagering process.