Methods Used To Control Fermenter Temps

[Gout]

I used to used to brew lager and hence a freezer with a temp controller was good enough, however as i am now brewing ales (i like the faster turn around and use WY1056 for my simple ales) The winter months of Melbourne have hit. Not only has my large freezer died (and been thrown out) i now have a smaller freezer that only fits one fermenter

I want to set up firstly a heater control for winter, then a heat/cool for summer.

Currently i am going to use a heater mat (i was given about 20) i have from past jobs and a home made pic controller to keep the mat and fermenter in check - sensor on the mat/base and one half way up the side of ther fermenter. I brew normally with 4x 25Lt fermenters at a time. (2 for the bar and friends to drink, one for me and one hopefully some age (a week or 2 )

What i want to know is:

if i use a heat mat, if i place it under the fermenter will this cause an issue with yeast on the base. - if so what should be the limit of the temp on the base?


I plan to limit the base heater to say 30 deg (heater mat itself) and then another sensor on the fermenter to limit the ferment temp eg 20deg. If the bottom heat is a problem i will place one on the side or 2 - one on each side of the fermenter within a camp foam mat to keep each fermenter warm.

Once i get this sorted i need to work out cooling for the darn summer.

I would love to make a fermenter jacket with temp controlled water but thats another story.

I may be going about this in a complex way so happy to see how others have done this. I have 4 fermenters so the temp controlled fridge wont work.

I might make a large box to fit all 4 then use heat and chiller from the freezer to controll these at a later date

All was well untill the very cold weather where my hot water bottles are just driving me mad and not working

 

[kenlock]

I reckon Asher's setup is the solution to your problem (provided you have the space) link (rota moldings)

Gives you the volume and temp control.

 

[Gout]

jebus thats a link worth linking - i shall study it tomorrow, sadly i dont have the fridge, room or fermenter but it might give me ideas


I was thinking if i build a 2x2 fermenter box eg 2 high 2 wide I would have a controller per section and then if i rig up the freezer with a large amount of liquid, then have independent temps for each section if i wanted it would work well - maybe a liquid control to cool and heat mats to heat.

heater placement may be an issue however if i build a box, the heaters might go on the walls of the box not the fermenter and then it might be worth while doing

i am not sure how this 'box' will stand up to a fridge when it comes to holding in the warmth.

 

[kenlock]

Once you get to a box which will fit 2 fermenters high, with room to move them in and out, a fridge or freezer that holds that conical fermenter won't be much higher. And it will certainly be much less wide.

If you do a search, there are a few threads which discuss the making of boxes for temp control. They use a variety of methods to control temperature.

 

[Cocko]

A good fridge and this running heatrr inside and you should be good yeah?

2c

 

[Gout]

i agree i WANT that 100Lt fermenter, however given i have the 4 new fermenters i might try get some use for now while i source these 100Lt con. fermenters and a fridge to suit. that really looks like a good long term fix to my brewing needs.

untill then i will try a makeshift controller to warm my babys through the cold.
beers!

Cocko - that was how i used to brew but now i do 4x brews, the fridge will not fit them so i am looking to expand. I will use that on the freezer to brew my lagers and special beers but the gulls that flock at my house each week get my mega brews which i try to brew 4x25Lt at a time to keep them away from my good beers

home brew and you will save money they say pffffff

 

[Cocko]

I brew 4 'batches' at a time myself...

2x 25L in 30L fermenters and 1 44L batch in a 60L fermenter...

I run 2 FM's, 1 controlling 2 heat belts wrapped around the 60L = Probe controller.

2nd running a heater inside a dead fridge, with 2x 30L Ferms inside, controlled by the standard probe:

View attachment 28929

The fridges are dead so I run frozen bottles for about 4 weeks a year!!

Sorry if it doesn't help but it works for me!!

 

[Gout]

cocko - this post comes in at a very interesting time...... my second freezer seems to be dead ( both had been left not running for 3 years)

I may be able to fit 2 30Lt fermenters in this one and like yourself run a set up to controll the heaters.

Secondly i have sent an email to the 100Lt fermenters to be - as per Ashers. depending on price, freight, and the need to find the right fridge this might also be an option.

I have also asked about the QTY for price reductions and its effect on freight so i may offer a mini melbourne bulk buy if its worth while and there is interest

 

[Bribie G]

If you are prepared to manually check up on your brews once a day, I've found that you can keep the brew in a dead fridge to within half a degree accuracy without a temp mate. Summer: dead fridge and frozen PETs. Winter: (doesn't get that cold, we are having a monster cold snap here in SEQ at the moment down to 6 at night, even so the beer stays at 17 / 18 on the garage floor ATM) but if interstate, a small lightbulb running under an inverted terra cotta plant pot.

What I've found is that a fermenter of beer is a fair 'heat sink' in its own right and raising or dropping the temperature is a bit like turning round the Queen Mary. After a while you just know in your bones how many frozen PETs for how long to acheive what temperature drop / rise. For example I have a Californian Common steam beer sitting on 13.5 in the fridge and going to drop it to 12 because it's still frothing through the airlock and I bet you anything you like I'll get it there very accurately.

Way before refrigeration brewers could control temperatures precisely using pipes of cold and hot water, ice caves, you name it. Yorkshire Stone Square brewing involved very accurate control within a couple of degrees F. and they could do it using double walled stone fermenters etc. Many ways to skin a cat.

 

[Cocko]

a small lightbulb running under an inverted terra cotta plant pot.

Slight OT - Does a bulb produce 'skunking' ? Is that what the pot is for or is to retain some heat?

 

[Gout]

i painted my globe black to try stop the effect (if any?) of the light.

I dont know how cold its getting on a melbourne night but i had ice on the car roof so the beer is finding it hard to keep up. Since yesterday i have placed all 4 fermenters on a heat mat each and given them some power to keep them warm. as you say the thermal mass is good as once i get the output about right it matches the weather. then i will try temp control once i get the time

 

[katzke]

Bloody hell. I live where it gets so cold in the winter you can get ice on the inside of the windows and I do not have any trouble keeping my brews warm in the winter. Now that it is Summer it is a chore to keep them cold enough but I found a wet towel around the fermentor in the tub worked for me even when it got up to 80F in the house.

Maybe you just need to get them out of the brew shed or put them in some place you can keep them warm.

Now if you are talking cold like 23C outside then we are in the same climate and you are just cheep and not only are your brews cold but you are as well. And for those of you that do not work in cold plants when it gets that cold the snot freezes in your nose. We call it nose hair cold because, well your nose hairs freeze.

 

[Gout]

Katzke, these are inside but dropping to about 13-14deg or so on average (day and night) due to the thermal mass. I dont have heating on them hence the idea of heater mats (which i now have on them and they are starting to bubble again - up to 18deg and will ramp it slowly back up to 20 or so to finish the fermentation)

- and yeah the room they are in gets cold - one bedroom place and the kitchen is where they sit - cant manage to sneak them (4) into the bedroom lol ( i did this once and the smell from them was horrid at peak fermentation and i was blamed as stinky so they got snuck back out)

I went away for 4 days and thought they would be ok but they have almost stopped at 1020 (OG 1050) so i will try warm them and get them going again.

I agree its not the coldest place ( i was living near scotland and that was colder than here however not below -10 I used to keep my drinking stock in the garage and no need for a fridge) but i still think these ale yeasts are not so happy under 15deg (Wyeast 1056)

currently i am going to look at:
100Lt fermenter and a fridge (temp controler - Asher copy)
2 fridges and my 4 fermenters (cocko copy)
a custom box with heaters and maybe ice blocks to keep cool in summer

 

[katzke]

Well you must be a victim of poor builders and room heat. I have a fairly average insulated house and just heat with a wood stove. On the coldest days last year I had to move the fermentor next to the stove and have at times used a heat pad to warm it up. Active fermentation generates heat so a well prepared wort and pitching enough yeast will keep things going until they slow down on there own. Like I mentioned only at the extreme conditions have I had to worry about helping the ferment ant it was caused by not having the wort up to temp or having enough O2 for a liquid yeast, or having enough yeast to get things going.

I was saving this story but it can get cold enough for house plants to freeze and I lived in a trailer one winter and it took me 3 days to get the water running and when I got the water running the sewer was froze and so on for 3 days. We were both sick for about a week after that one. No more trailers for me I tell you.

And for you that wonder what I am talking about rent the move The longest Road with Lucille Ball and Desi Arnaz.

 

[Bribie G]

Slight OT - Does a bulb produce 'skunking' ? Is that what the pot is for or is to retain some heat?

I read it on a thread a few weeks ago, the pot is to stop any skunking and also makes a nice little heat diffuser I guess. Sorry don't have a photo, Cocko

 

[krusty_oz]

Another heating option is a submersible fish tank heater, $20 from the pet shop and clean with your preferred cleaner/sanitiser. Only problem is getting it into the fermenter.
There are 2 ways of getting it in there. First (my method - warning 240V wiring involved) drill a second hole in the lid of the fermenter, cut the plug off, pass cable through and rewire it with a new plug (choose one that is assembled with a screw). Seal up the gap around the cord in fermenter with duct tape (or use suitable sized grommet). When I don't need the heater I just cover hole with duct tape and it seals fine.
My mates method (safest as no need to wire plugs) was to remove O-ring drill a hole in lid, then cut a slit in the side of the lid to push the cord through, seal the slit with duct tape or silicone. Lid doesn't seal as well (may not make the airlock blurp) but keeps the ale's nice and warm.

 

[pdilley]

I was thinking of giving the direct method a go but at 300w I thought I might get some hot spots when it fired up inside the fermenter. As an alternative method I got a 50 gallon storage container from Bunnings, stuck it in the fridge, poured water in it, dropped the heater straight into that and then lifted the fermenter and placed it into the water as well. The water heats up rapidly and then the heat tranfers more slowly between that and the fermenter for gentler even warming.

It does however mean after a week you will have a condensation buildup in the brew fridge. So if direct is not an issue at 300w I may give that a go as well for comparison.

Cheers,
Brewer Pete

 

[krusty_oz]

Forgot to add, we only have a 50W heater, will be fine up to 30L. Experience with fish tanks is that more wattage is needed for a larger volume or very cold conditions (although given the insulation in a fridge, it probably wouldn't need too much compared to fish tank that has bugger all insulation).

Once bottled, put the bottles in an esky, put the heater in it and fill with water (just enough to cover the length of the heater), will keep the yeast warm while they carbonate.

 

[rich_lamb]

Hi Gout,

as to your original question I would think you can run the heatpads under the fermenters no problem at all - don't get paranoid about overheating the yeast or anything. I used to do this all the time with no ill effects as the heaters are really weak (I think about 25W?) and even at steady state are not an issue.
So your temp control can just pick up the side of the fermenter and be nice and simple, though I would put insulation over the OUTSIDE of your sensor like holding it under a foam pad or something.

You should find the duty cycle of your heating is quite low even in Melbourne winter.

Now if you want to heat and cool, and since you seem to be capable of working up your own control you could make one of these:


which is an insulated box with a peltier device and a couple of fans. Whatever you use to drive the heat/cool an insulated box is usually the starting point. Most guys just use a fridge, which I guess is a recycling option.

 

[Gout]

thanks all for the replys - a few home brews mean i did not read these as close as possible ( and the lads came over to sample the beers)

The heat pad(s) are working well 20deg so far - a simple on off control should be ok once i get that done maybe tomorrow.

B & T- i have a large peltier but i found it was not good enough and for 4 fermemters it was a pain. Shame though

I will look at the 100Lt and a fridge and these heater mats ( i only want to use them as they are free) but so far they look to be doing the job.

I have 32V on each and they are keeping warm ~300W at 110V AC so once the control works i will test mains Voltage (2x110V mats )