Using An Aquarium Heater To Regulate Fermenting Temperature

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Hi All,

At D&G's G&G BIAB demo a few weeks ago, there was a discussion around using an aquarium heater for keeping ferment temps high enough during cold conditions.

Dan, I thought I heard you say that you use an aquarium heater and that you just submerge it in your fermenter. Is that right?

I'm only asking because I've just been doing some reading and the early running seems to be with putting the heater in a water bath in which the fermenter itself is sitting.

Obviously it would be simpler to put the heater into the fermenter itself - but I don't want to do this unless it's safe to do so.

Any tips?

Cheers

Mike
 
I use a submersion heater for each of my fermenters. The proper brewing ones come with a airtight rubber stopper thats designed to be placed in a hole cut (with a holesaw) in the fermenter lid.

The ones that I use are designed to be entirely submerged within the wort and have been pretty good (only thing thats annoying is making temp adjustments because of the infection risk)
 
I used an aquarium heater submerged in my brews last winter, that was until it dropped in a bit further and infected it due to some nasties under the plastic top. I know put the heater in a 2.4L berri juice container full of water and use it to heat the fridge or esky space.
 
I used an old immersion heater in the fermenter for some years with no problems. Until I dropped it and broke it. I bought a new one, but the plastic parts on it started to be eaten away after a few brews? I have since used a brew pad coupled with a thermostat...
 
I started using an aquarium heater by putting it in the fementer, use cling wrap so simply stuck it under the rubber band. However found it a lot easier and safer to stick both fermenter and heater in a water bath. If you need to adjust it for any reason easy access, and the rubber tops seem to be a place where infections would love to hide. Also this way it seems to distribute the heat a bit better, those aquarium heaters get quite hot when on, i know if i put the thermometer near the one in the fish tank the heat spikes quite a bit. (and unlike the fermenter this water is constantly being recirculated by the filter / pump.)
 
I have used Immersion aquarium heaters for fermenting my brews.

What I did was cut the plug off the heater, drill a hole in the top of the fermenter (cap) to take the wire, position the heater in the fermenter then glue in place. Attach a new plug, set temperature to 20C (lowest setting).

The heater is sanitized with the fermenter.

Did not have any problems with this method except could not brew below 20C. Now use fridge/ fermenter cabinet controlled by digital temperature controllers.

Need 100W heaters down here in Tassie.
 
I used an aquarium heater submerged in my brews last winter, that was until it dropped in a bit further and infected it due to some nasties under the plastic top. I know put the heater in a 2.4L berri juice container full of water and use it to heat the fridge or esky space.


How effective have you found this to be? I'm currently looking for a solution to the cold temps that exist in my garage and setting up something like this combined with my fridgemate (just change the settings and it can run the heater).

I'm just thinking that a 2.4L volume being heated to whatever the highest those things can run (30deg??) would struggle to heat a volume of air sufficiently enough that it would then keep the brew warm....
 
many years ago i used to use an aquarium heater submerged in fermenter with no ill effect, just sanitised in the usual way.
 
many years ago i used to use an aquarium heater submerged in fermenter with no ill effect, just sanitised in the usual way.
i have been using Jager quaity immersion heaters for last while. aquarium heaters are not all made the same. the cheap ones do not disperse heat properly and lack a decent thermostat. i submerge my 30L fermenter in a tank of water: a plastic 50L rectangular container bought at office supply place. i heat the water (20L) in the container with the Jager. this method means you can adjust thermo temperature if required and keeps nasties out of wort. also supplies a more even heat to fermenter rather than directly putting heater into fermenter. last 2 ale brews have sat at 19C no bother.

i plan to brew dark ales all winter long.

pics available on request.
 
I drilled a hole in my fermenter's side, put in a grommet and wedged a fish tank heater in up to the hilt.
Advantages: Can adjust the temp if you want, cap section is not in the wort.
Disadvantages: You have a hole in your fermenter

Mine never leaked and now that I ferment in a fridge I've put a blanking grommet over the hole with no leaks or issues at all.
If putting in the wort, get the smallest size/power heater you can. A small one on for longer will create smaller temp fluctuations than a large heater on for short periods.

If putting your fermenter in a water bath, make sure ther water is sanitised regularly, you don't want infections through the tap.
 
I use an immersion aquarium heater in a 120l storage box with water. Hold a nice temperature during winter and it might even work in summer......

I actually had to use 2 as the first i bought wasn't powerful enough as it is in my shed and the ambient temperature is a bit nipply.
 
Hello all,

What Wattage Immersion heaters are people using ?

I just ordered a 300 watt model from ebay. I plan to immerse the fermenter in a water bath so I figured I'd get one with some punch.
I would imagine boiling fish would be an undesirable feature of an aquarium heater so i think it will be fine.
Can't go wrong at 15 bucks.

Cheers

David
 
Many years ago, my first fermenter had an aquarium heater fitted through the side of it.........worked well.
I stopped brewing and do not recall what ever happened to that fermenter.
I just use a heat pad these days
 
david72,

Im using a 50 watt and a 150 watt so 300 watt should be plenty.

I think i have seen the one you are talking about on ebay. Stainless steel with remote temperature control?

I guess it all depends on how much water you are planning on having in your bath. I have about 20-30 litres and the 200 watts does fine and it is getting down to pretty low ambients (sometimes 0).

Only one thing that would concern me and that is if it gets too hot would it melt the plastic? Mine don't i can even touch them (while they are immersed).
 
How effective have you found this to be? I'm currently looking for a solution to the cold temps that exist in my garage and setting up something like this combined with my fridgemate (just change the settings and it can run the heater).

I'm just thinking that a 2.4L volume being heated to whatever the highest those things can run (30deg??) would struggle to heat a volume of air sufficiently enough that it would then keep the brew warm....

Can't comment about the aquarium heater and not trying to cut cdbrown's lunch but during winter in Melbourne I run a heatpad off a fridgemate inside a fridge. Not under the fermenter but just in there somewhere heating the space rather than directly heating the beer by contact. Works like a charm and worth thinking about if you happen to have access to one.
 
Yep, been using cheap e-bay aquarium heaters in my brews for years. I directly submerse them.. but I suspect that a tub of water with the heater and your fermenter both in there is just as good and I have done it that way with success... just that it takes up a bit more room and makes a bit more mess, important to me in a 2 bedroom flat. Also doesn't work with my particular solution for keeping temps down.

The plastic top... needs to come off. It does nothing and is only there for looks - the unit is sealed by a bung shoved in the top under the plastic lid thing. The only thing its good for is as a hiding place for bugs and nasties to hide. Mine have all been pulled off and the heaters are fully immersed.

They hold temp pretty well - if you are a super freak it might not be good enough... but one of the strip thermometers on the side stays steady as a rock during an average fermentation. They aren't "accurate" though and you will have to do a few trial to see what the correlation between your set temp and your actual temp is - but once you have it, you're apples.

I use 100W heaters - they are fine for even double batches in a 60L fermenter. But if you were going to use the heaters in a water bath instead of directly in the fermenter - I would get a grunty one. I would also buy a cheapy pond pump and use it to circulate the water around in the water bath. Plus - a little bleach in the water to keep it bugs free and stop nasties getting into your fermenter tap.

Most of them only go down to 18 or 19C - so if you want lower temps you have to pay for expensive ones OR as I do, run it off a PID. Heater set to maximum so it turns on whenever it has power... PID probe attached to fermenter and PID controls when the heater gets power. I use this set-up to do my lagers.

In summer (and for lagers) I brew in an uncontrolled fridge - and that's one of the reasons I like the immersion heaters. My fridge is still fully finctional as a normal fridge, freezer, keggerator etc... but with the addition of a bit of insulation to cut the heat transfer rates down, I can also be brewing an ale in there at 20C. Yeah - I burn a little more electricity, but not nearly as much as I would running another fridge just for fermentation.. and I don't have to find room for one either. I personally wouldn't use a fridgemate/tempmate for this purpose - the hysteresis on them is too high and the fermenter temp swings up and down too much. Need a PID that has some smarts to get away with it.

TB
 
This is the one I have ordered. They come in 50, 100 200, 300W. Even if they are rubbish they are cheap enough not to worry about it too much. Only go down to 19 deg but I have a dig thermostat if required.

here

Yeah, Immersing the fermenter in a tub uses a bit of space but I have to move operations to the garage or swmbo will enforce prohibition. Currently using a fan heater in a european laundry, which is quite inefficient and not keen to leave it on when I'm not home.



Off topic, Thirsty. Will you be doing the BIAB "Brew off" at G & G coming up?


Cheers

David
 
However found it a lot easier and safer to stick both fermenter and heater in a water bath.

Dan, sounds like an excellent idea - I have an old tropical fish tank heater but always been worried about infection and the fact that it gets very hot.
I might pull out my heater and try the water bath idea - I like that it will not change the temperature too fast or in one spot.
 
I solved my problems with two 40 watt incandescent lamps mounted on a board underneath my fermenter and plugged into my Craftbrewer controller. This really works well and does not involve anything going into the wort.
Cheers Altstart
 
How effective have you found this to be? I'm currently looking for a solution to the cold temps that exist in my garage and setting up something like this combined with my fridgemate (just change the settings and it can run the heater).

I'm just thinking that a 2.4L volume being heated to whatever the highest those things can run (30deg??) would struggle to heat a volume of air sufficiently enough that it would then keep the brew warm....

It seemed to do the trick alright, was probably set to about 26 or so on the dial to keep the brew around 18C while in the fridge due to the large air space. But when in the esky which is far better insulated than the fridge and much much lower volume, was pretty much set to 20C and rarely switched on even with th 1C mornings.

Esky is an Icekool one from BCF which when put on it's end is just wide and deep enough for a fermenter and tall enough to put the heating bottle (or frozen bottles) on top.
 
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