Heat loss of FV's during Winter months

[QueenCityBrew]

Hi folks, newbie brewer needing expert opinions again.

For our (2) 15 BBL Uni's; we are concerned about them losing heat during fermentation in an unheated space during the Winter months. We want to brew ales exclusively at between 60F and 66F and we have a glycol chiller to maintain them during the summer months. Our facility, however; has no heating/AC capabilities. During the winter (like now) we will have consistent days of outside temp around 42F which means our ambient temp inside our space will stay pretty close to that. How do we insure that our Uni's maintain their target temp during this cold period? we understand the exothermic properties of fermentation during yeast ramp up and such, but after the exothermic stage of fermentation, can we expect the insulated Uni's to maintain that ferm temp or drop due to the lower ambient temp around them?

[troybinso]

My fermentation room is in the low 40's right now. You pretty much nailed the problem. If you pitch the yeast in the mid-60's, you should be fine for about 90% of the fermentation because of the heat created during fermentation. The problem comes at the end of fermentation, when there is less activity in the tank.

I have set up a kind of quick disconnect for my glycol lines that allows me to run warm water through the tank as things start to slow down. It is not very precise, but it seems to get the job done. I have heard of people using space heaters under the tank, but in my situation, I am not sure this would work.

One last thing. Be sure to take the 40 degree farenheit steel of the fermenter into account when you are setting up your heat exchanger after the boil. It will drop the temperature of your wort when it flows into the tank. You might get a slower fermentation this way, creating less heat and have some real problems with attenuation.

One last, last thing. Get some heating into your fermentation room so that you don't have to deal with all of these problems. Believe me, it is a real hassle, and worst of all, it affects the quality of the beer.

[JoeV]

pitch warmer

We have the same sitiuation, but have not experienced any problems, or need to heat the fermentor. Pitch a little extra yeas, pitch a little warmer and you could wrap some cheap insulation on those tanks

[gitchegumee]

Pardon me for being the naysayer here, but why do we all think that we must control the temperature to an exact degree? Some of the best beers in the world (IMHO) come from fermentations that are less controlled. I'm sure you could select a yeast strain that has favorable diacetyl reductions at lower temperatures and then run your fermentations as they will. What do we benefit from having an exact and "perfect" fermentation temperature? I argue that we can get some extraordinary flavor profiles from a range of fermentation temperatures. The only problem with this might be the seasonal change in ambient temperatures. Consistency is key, not some presupposed ideal constant temperature. And a "wild" fermentation environment without added heat is "eco-friendly". Here in the tropics, I'd love some free refrigeration! And it could represent a house character that might not be duplicated elsewhere. Keep it simple and don't fight the force. Use it. Cheers!

[jarviw]

What do we benefit from having an exact and "perfect" fermentation temperature? I argue that we can get some extraordinary flavor profiles from a range of fermentation temperatures.

I love this argument... and totally agreed!
I think, much of our brewing textbook knowledge is from work and research done in the mega brewery making lagers. That makes beer cold.

[troybinso]

I agree that consistency is the key, but the problem I face is that it is difficult to be consistent with the temperature of the fermentation room. I also don't feel like you need to keep your beer at +/- 1 degree of "optimum temp", but when the room you have the beer in is 25 degrees lower than the optimum temp, then you are really fighting a losing battle. I would suggest figuring out a way to keep your room at a temperature that is at least close to you fermentation temperature.

[Moonlight]

Try turning off the cooling during the last third (or so) of fermentation to allow a running start at full attenuation. Let the fermentation temp rise a couple degrees. The higher temperature will affect flavor less significantly after peak krausen. Fermentation generates heat so if the yeast is vigorous enough, you should be just fine.
Even so, some yeasts are more tolerant of temp fluctuations than others.

[canyon]

Relax, don't worry, have a whatever brew

What you are looking for you either can hire or earn... experience. We can share some good tips but ultimately the brewer has to get the feel for all the variables and how tweaking them can affect for results. Here in Alaska, some of us ferment in cold situations whether we want it or not. Ale ferments can take longer in the winter of course and may require supplemental heat at some point if you don't nail the pitch temp just right for where the yeast is at or what the expected temps in the ferment room will be or whatever. But over 10 bbls in insulated uni's is relatively easy to hit a good temp range, particularly at the tame temperatures you are talking about. Some of us try keeping three barrels (or less!) in single wall and even open fermenters in ale ranges with temperatures approaching freezing in the room and with a little experience it can be done successfully if you play it right. Don't worry about it!

[QueenCityBrew]

BIG Thanks!!

Thank you all for the range of ideas and insights into this issue. It is really cool to see the involvement of the brewing community and the willingness to help out us newbies. We had many of these ideas in our heads, but feared our lack of experience could lead to disastrous results costing lots of $$ that we simply would not be able to withstand. Hats off to ALL of you for the education and support you have provided to us. We look forward to meeting many of you at upcoming festivals and events. We will put these ideas you have shared to practice and hopefully grow as brewers to match the abilities you gentlemen (and ladies) bring to our great industry.

[Fred Scheer]

heat loss

Hey, another factor is calculating your BTU's at the FV and go from there..
252 BTU are generated for every lb of extract during primary fermentation.
And ~75% of that heat is created in the first 45 hours.
Keep in mind that cooling rates are very crutial part.
Cheers,
Fred

[dick murton]

I thought I had already posted a response, but...

Providing your vessels are reasonably well insulated, and a few inches of fibreglass or a couple of glass foam type material will do, then the fermentation will heat up OK - to the extent you will need to cool the FV. It's not perfect, but if necessary run some copper coils through the fermenting wort and pass cold water through the coils - a pretty traditional method of cooling. Once you get a little used to it you should be able to control using just a had thermometer, but are better with auto control. It's not that expensive to set up. The only problem will be if your water supply is warmer than your fermentation temperature - in which case you will need to sort out some chilling

Although I like the idea of fermenting freely, we had end of fermentation pHs varying by 0.5, with a definite difference in taste when we had uninsulated FVs, so if you want consistent product, then you need to insulate. Untidy, but get some loft insulation from the local hardware store to get you going if the FVs are not insulated, and then wrap in plastic.

[Johnson_Thermal]

Source of "free" heat

This may not be practical in your situation, but the heat from your condensers on your walk-ins and glycol you could be used to heat your space.

The low tech solutin is to duct the air in, with a damper that you turn to duct out in the summer. Or it may be possible to just detach the duct in the summer.

A more sophisticated method would be to install a second condenser inside, and you pipe to both condensers. You use a "heat reclaim" valve to go between your summer and winter condensers. Of course this would require a refrigeration contractor.

But if you decide you need heat in the brewery you will have to buy the equipment and fuel anyway.

[SRB]

This may not be practical in your situation, but the heat from your condensers on your walk-ins and glycol you could be used to heat your space.

Thats what were doing!

It may be obvious but seal your building with caulk, foam ...towels whatever as best you can. Air leakage is half the battle with heat loss.