What do you use to increase temps of your FV safely? heat belt? light?

[gunn]

Gunn are you not worried about the elements overheating if its recirculating hot air?
I'd only feel comfortable using that if it was controlled by a PID within a really small temp range to minimise the time it's on.

My probe dangles in the fridge so it gets hit with the hot air quite quickly. It is usually only ever running for ~5 seconds.
I understand this is quite crude using an STC1000 but I find its working good for me. I never looked into it but I would hope an open circuit to the sensor would stop all outputs?

I struggle to understand why so many people in aus are trying to heat their fermentation vessel whilst I,m constantly having to cool mine, even with ales to maintain 18-20c and even more so for lagering and cold crashing.

Im in brissy and my shed gets quite hot, but still overnight during winter I would find the fridge temp would drop too much. In saying that I do not monitor the liquid temp and work on keeping ambient temp constant.

 

[Tropico]

http://www.ebay.com.au/itm/Dual-PID-Digital-Celsius-C-Temperature-Control-Controller-Thermocouple-REX-C100-/301658551308?hash=item463c40340c:g:SvkAAOSwo0JWLyzI

The REX-C100 come in different versions not limited to:

Relay contact
Voltage impulse (SSR) Your link
Current output 4-20mA (also SSR)

Your normal house plug is 10amps which would drive 2400watts. The 3amp relay would drive 720watts. If you could get 40amps at 240volts it would be 9600watts

 

[mattjm]

Im in perth so yeah it hasnt got to temps yet that heating is necessary, ales i tend to try to hold at 18c for most of the fermentation then allow it to come up to low 20s to finish and diacetyl rest prior to cold crashing and racking to a keg. Just seems to me that keeping the temp down and fermenting a little slow is the key rather than heating to keep it in the upper temp rage to see vigorous activity from the airlock.

Using the brewpi I am monitoring the fridge temp and beer temp (thermowell) and find the cycling of the compressor through the night to be relatively consistent over 24 hours so in these temps ambient temp affects the well insulated fridge very little. My next step I really want is a digital SG meter that can control the algorithm/profile and automate my kickoff, diacetyl rest and cold crash based stage of fermentation.

 

[gunn]

Im in perth so yeah it hasnt got to temps yet that heating is necessary, ales i tend to try to hold at 18c for most of the fermentation then allow it to come up to low 20s to finish and diacetyl rest prior to cold crashing and racking to a keg. Just seems to me that keeping the temp down and fermenting a little slow is the key rather than heating to keep it in the upper temp rage to see vigorous activity from the airlock.

but also you dont want the temperature to swing each night during the cooler months.

 

[mattjm]

I dont find this to be an issue, my temps/activity is logged 24/7 and my compressor is still cutting in throughout the night.
I may be wrong but I often wonder if the taste of alot of new brewers brews would not be improved if they stop trying to use belts and mats to heat their fermenters and let it brew 5 to 10c cooler and slower

 

[TheWiggman]

You're right. The K type thermocouple that comes with the PID are not so flash and only work at +/-1.0C.

I picked some up PT100 (3 wire) thermocouples that allow you to run at +/-0.1C resolution with the REX-C100.

I use either an old Kelvinator refrigerator or a dedicated fermenting cupboard as well (depending on the season).

You could probably set-up something to immerse them, but I just tape them to the side of the fermenter with some insulation over it.

IMAG02142.jpg

Sorry to steer this off topic but... do you mind snapping that ruler and seeing if it is in fact shatter proof? I don't believe it. I need to know for some reason, like an instinct or something.

 

[gunn]

thats good to know, im guessing the heat during fermentation negates the difference of outside temp.
tbh ive never monitored during active fermentation in the night and just assumed on a colder night it would also drop inside the fridge.

when I setup my equipment, I had tested with an empty fridge and it was getting down to 12deg overnight during winter.

does the temp drop once primary fermentation is complete? also maybe your fridge/freezer etc is better sealed then mine

 

[mattjm]

At the moment im testing my new spark core with an empty fermenter and finding the same thing, also worth remembering the beer is a much slower medium then air so a drop to 12c on a cold night would actually take a considerable amount of time to drop the beer to anywhere near 12c. Worth noting though perth temps are lucky to get down below 15c outside at the moment and would be well above in my insulated fridge inside.

 

[Tropico]

if it is in fact shatter proof? I don't believe it. I need to know for some reason, like an instinct or something.

"Shatter resistant". I would, but then I wouldn't have a perfectly good ruler

 

[Rocker1986]

I struggle to understand why people bother measuring the ambient air inside their brew fridges. It's the fermenting beer temp that you want to measure and control, so why would you measure and control something else? Obviously a temp probe taped and insulated to the outside of the FV isn't absolutely precise like something sitting in the actual liquid but it's still far better than guessing where to have the ambient air at.

 

[Tropico]

Initially the temperature differences between wort, the fermenter and the surrounding air temps would lead to inaccuracies. Eventually everything comes into equilibrium at the same temp.

 

[bolfenk]

STC-1000 (15€) and Ceramic Heat Emitter - Lamp (20€)

 

[mattjm]

Im measuring the temp of my beer and an algorithm that uses PID values to calculate the effect of the fridge air temp compared to the beer. This means that there is no differential in the beer temp and it stays within.1 of the set point without short cycling the compressor. Trying to control a fridge purely based off the temp of the beer would be much more inaccurate as the fridge can and will cool well below the set point before the temp of the beer changes. In the scenario you describe the control would be more precise because the probe is taped to the beer as opposed to submerged in it.

 

[gunn]

my reasons are;
1. measuring outside of the FV is imprecise anyway.
2. keeping ambient temp is easy.

If you have the probe on the outside of the FV (with some insulation from ambient air as well) then how long does the compressor run and how cold does the ambient temp get before the liquid temperature can change enough for the relay to cutout? Does the FV liquid temp then continue to get colder (as the fridge ambient air is still low) untill it is now necessary for a heating output? How long does it need to heat to now bring that temperature back to the desired point? What about people who dont use heaters in their fridges? If you have a heater, what type of heater is it? Does it heat in the middle of the FV? Does it "overheat" the lower/centre of the beer before the sensor can see this and then stop the heating output?

I feel like there is way too many variables, too many considerations. just keep ambient temp as constant as you can and let the yeasties go to work.

The only other solution in my mind is with glycol systems.

 

[mattjm]

as much as I like the idea of glycol jacketed stainless conical fermenters (bling bling) there is no real advantage of this to the homebrewer. Like you say if the ambient temp of the fermentation chamber can be controlled to a constant that is 100% adequate to avoiding any off tastes that are derived for fermenting at too high a temp and issues with not fully fermenting or yeast dying due to temp dropping too low.

I actually think this is one area where the homebrewer has a massive advantage over the commercial beweries, due to the size of most FV,s they can easily be housed in a fridge and the temp can be controlled much more acurately then trying to control a large FV with thousands of litres of beer that must be chilled via glycol because controlling the ambient temp surrounding the vessel is not economical.

 

[gunn]

too right mate. this is homebrewing after all.

 

[Tropico]

I don't believe it. I need to know for some reason, like an instinct or something.

Like telling someone "Don't touch that. Its hot"

 

[talco92]

does the temp drop once primary fermentation is complete?

yep. heat is a byproduct of the yeasties working. If they finish work, or go on strike, then beer temp will drop to match ambient temp.

 

[gunn]

yep. heat is a byproduct of the yeasties working. If they finish work, or go on strike, then beer temp will drop to match ambient temp.

the question was in reference to his setup and the ambient temperature of his fridge in comparison to the desired temperature point.

 

[talco92]

the question was in reference to his setup and the ambient temperature of his fridge in comparison to the desired temperature point.

haha thought you were asking a rookie question