Brewing big and maintaining temperature in winter?

[sentfromspain]

Hi all, I spent last winter fermenting my beer inside a country house during the winter where the lowest the room got was about 15 degrees C (59 F). This summer I have a milk tank in the garage of the country house to maintain fermentation temperatures at a nice 18 C (64 F) which will really make the whole process a lot easier.

When it gets back to winter, however, switching back to fermenting in the country house is not going to be much of a viable option. The temperatures, when it is coldest, fluxuate between -2 C at night (28 F) and 17 C during the day (62 F). The milk tank has a 540 liter capacity, and while it is in a garage, that garage is not very well insulated and will definitely reach freezing temperatures.

My question: does anybody know if the fermentation from the 500 liters of wort will generate enough heat to maintain a steady fermentation despite the cold temperatures? I know some breweries in Colorado don't have to use a heating system for their tanks despite the snow, but those tanks have thousands of liters.

 

[mtnagel]

I wouldn't count on fermentation maintaining a steady and appropriate temperature with those temperature swings.

What I do in the winter is use a water bath, an aquarium heater and a stir plate. The heater heats up the water and the stir plate maintains constant motion of the water to maintain a constant temperature. Doesn't look very pretty, but it works.

Edit: I just reread the volume and didn't realize it was so much. I've only ever done 5 gal or less, so obviously my advice won't work for you.

 

[Smellyglove]

Hi all, I spent last winter fermenting my beer inside a country house during the winter where the lowest the room got was about 15 degrees C (59 F). This summer I have a milk tank in the garage of the country house to maintain fermentation temperatures at a nice 18 C (64 F) which will really make the whole process a lot easier.

When it gets back to winter, however, switching back to fermenting in the country house is not going to be much of a viable option. The temperatures, when it is coldest, fluxuate between -2 C at night (28 F) and 17 C during the day (62 F). The milk tank has a 540 liter capacity, and while it is in a garage, that garage is not very well insulated and will definitely reach freezing temperatures.

My question: does anybody know if the fermentation from the 500 liters of wort will generate enough heat to maintain a steady fermentation despite the cold temperatures? I know some breweries in Colorado don't have to use a heating system for their tanks despite the snow, but those tanks have thousands of liters.

500 litres of fermenting wort will definitely make some heat. But ony when the fermentation is at its most active part, which is usually a few days. After that you can't rely on the beer to maintain heat.

This doesn't smell cheap. Even though the garage isn't insulated, you'd still want to insulate and have some sort of temperature control on the fermentor. It would be a shame to ferment that volume of wort without temperature control and see the batch "ruined" because the lack of it.

 

[rlmiller10]

Is there fermentation vessel in the milk tank or is the milk tank the fermentation vessel? I assume the milk tank is the fermentation vessel. In that case can you insulate the milk tank with a fiberglass or foam insulation? That would help reduce the amount of heat needed.

The type of heat will be the challenge I see. If the heater is submersible in the tank you will want low power so it doesn't get too hot. Most milk tanks I have seen have a mixer the circulate the milk or in this case wort. That would help avoid any hot spots. Perhaps just a space heater under the tank if there is clearance.

You will need a temp controller but an STC-1000 will do that. Not rated for a heater amperage so you would need to have the STC-1000 control a heavy duty relay or a soleniod if a mechanical switch.

Just some thoughts on redneck engineering.

 

[sentfromspain]

OP here: The tank is the fermentation vessel. We removed the mixer since it wouldn't be of any use during the summer. I could wrap the monster with some of the heat insulation material they use for chimneys which will help retain any fermentation heat clearly, any making sure the fermentation didn't go over 18 degrees wouldn't be a difficulty, but raising the temperature via the fermentation tank isn't much of an option.

I thought that maybe I could construct a box using insulated panels so the cold temperature swings wouldn't cause such an impact, but if the temperature wanes after the main activity then I am not sure how well the whole set up will work.

 

[rlmiller10]

If it is well insulated the heat requirements will be low.

No mixing leads me to prefer some sort of bottom heat. Is there a space under the tank? If there is space, or if the tank can be raised to make space even a heat lamp might be enough.

The key is insulating well so the heat requirements are low. It will be a contained system so if you can get the BTU of heat loss low the BTU of heat needed is low.

My fermentation chamber is a refrigerator in my unheated show. For heat I have a little electric pot used to keep cheese dip or other food warm. It does not get hot enough to boil water and only holds about a liter so very low thermal output. But even when the temp was down around 10 F, approx -12 C it still maintained my wort at 18 C.

So if well insulated it doesn't take much of a heat source.