Idea about temperature control of fermentation

[mirsultankhan]

I was looking at some equipment for maintaining the temperature of a fermentation vessel and noticed that there was a kind of submersible thermostatic glass heater which resembles almost identically the aquarium heaters that i have on my two aquariums. One is 55 gallons, about 220 litres and the other smaller. These aquarium heaters are digitally controlled and i can at any time raise or lower the temperature without having to actually go into the aquarium water because of a sensor that is submerged. The entire unit cost about £15 I think. The more simpler ones have a thermostatic control on the top of them which you can set. For a five gallon aquarium they cost about £8-10. Now this is quite a difference when i noticed the brewing heaters which were three times the cost and yet looked identical. A simple thermostatic heating element housed in a glass case.

I was wondering if one could use a simple aquarium heater to maintain a constant temperature in the fermentation vessel for it appears to me to be exactly the same thing. If one does not intend to place the aquarium heater directly into the fermenting beer through a hole in the bung then it could be possible to stand the fermentation vessel in water and heat the water to maintain a constant temperature of anything from 20 Celsius up to about 27-28 Celsius.

Whether this is necessary for success or has any bearing on the finished product I cannot say, but its of some interest for me to find out.

 

[Fil]

folk do use em, most i think via a secondary bath standing the fv on a couple of bricks in a builders trub or similar and heating the water the FV sits in,

this removes any risk of infection from something harbored in the fishtank heaters nooks and cranies (lid cap seal for example), and the risk of possible scorching of the wort that comes into direct contact with the heater, when using a 25w ebay job myself this way it worked a treat after covering in a sleeping bag and keeping in an unheated room over winter.

 

[mirsultankhan]

folk do use em, most i think via a secondary bath standing the fv on a couple of bricks in a builders trub or similar and heating the water the FV sits in,

this removes any risk of infection from something harbored in the fishtank heaters nooks and cranies (lid cap seal for example), and the risk of possible scorching of the wort that comes into direct contact with the heater, when using a 25w ebay job myself this way it worked a treat after covering in a sleeping bag and keeping in an unheated room over winter.

How awesome! so its already in practice, yes makes absolute sense to place fermentation vessel in water and heat that.

 

[DoctorMick]

I use a fish tank heater, cost less than a tenner and it does a superb garage even in the garage at this time of year. It's in a trug not directly in the fv which cost another 4 quid. I'm about to get another fv so it'll be going in an identical setup.

 

[baggybill]

I initially thought about going down the 'trug' route but due to numerous posts of successful brews with no infections using the direct immersion route, I opted for this.

I set up my rig (see photo), set the temp, chucked it in, job done. No worrying about short brews 'floating' in the trug and falling over etc.

The problems I encountered, across three individual brews/immersion heaters were:

As per Amazon reviews on the heaters, temps set on the top of the unit did not match actual temps measure on external therms. Temps measured were generally 3' to 4' lower (triple checked this with a third thermometer - temps OCD? Yeah, I know <sigh>)

This meant disturbing my brew to pull the unit and increase the temp setting on it.

To make matters worse...

The damn thing came out caked in krausen, which meant I had to find a sterilised rag to clean it so I could actually see the scale <sigh>

I'm still not keen on the trug route as I don't want to have to check it every day to make sure the 'rubber suckers' are working and the heater element has not worked loose and is lying on the bottom / plastic. Or worse still, my fv has floated over <gasp>

Plus my build (see my other photos) is a tight fit, trug + water + fv + brew = serious amount of weight to shift!

I wasn't aware that there was immersion heaters you could externally control the temps on. If I was to invest again, I would def go down that route. Even if it was twice the price (my Hidom 50w's were ~£7)

I've no issues now with direct immersion, 10+ minutes soak in Star San kills any bug, but might be an idea to test your unit on a fv full of water first - or err on the side of safety and set it high.

Hope that lot helps, good luck

 

[brewpirate]

In an aquarium you have filters moving the water around so the heated water is dispersed throughout the tank in a FV there isn't any so I would be concerned about hot spots. I am leery of putting anything in my fermenters nice to see someone gave it a go.

 

[baggybill]

> the heated water is dispersed throughout the tank in a FV there isn't any...

hmmm... look closer... a lot closer!

It's amazing the amount of movement created by the yeasties. Puts a lava lamp to shame! Have you never heard of blow outs etc.? Trust me, there is plenty movement happening in there... I still get caught out.

I topped up a Wilkos strawberry wine (with cooled boiled water) after 5-6 days, came back the next day and it had spray painted the place <sigh>

Maybe not so much near the end of fermentation, mind you, but then again, I've yet to meet someone that would call 18.5'C a 'hot' spot :-/

Did my Coopers lager at 18.5', did two wines at ~22'. Chardonnay had a blow out every day for 3 or 4 days <--- no movement?

Large trugs are cheap (<£5 @ B&Q) but, now that I've tried, tested & calibrated my heaters, I'm gonna stick with the immersion method for speed/ease of use.

If you do decide to go down the trug route, someone on here uses a fish tank pump to circulate the water in the trug, which I though was a great idea for an extra couple of quid.

It's funny though, I was so not for the immersion method way back at the start of my research. Didn't want anything touching my brew etc. Even regretted it a bit at the start of my last brew but now that I know what the units can do, my next brews will be set and forget :-)

Edit:
S***, apologies Brew Pirate, I thought mirsultankhan had posted that reply. I spent a good deal of time deciding which route to go down and though I would share my experiences.

I'm just going to nip down to my garage and prize my foot out my gob!

*I must not evaluate my products <cough> and post on forums at the same time :-/

 

[brewpirate]

> the heated water is dispersed throughout the tank in a FV there isn't any...

hmmm... look closer... a lot closer!

It's amazing the amount of movement created by the yeasties. Puts a lava lamp to shame! Have you never heard of blow outs etc.? Trust me, there is plenty movement happening in there... I still get caught out.

I topped up a Wilkos strawberry wine (with cooled boiled water) after 5-6 days, came back the next day and it had spray painted the place <sigh>

Maybe not so much near the end of fermentation, mind you, but then again, I've yet to meet someone that would call 18.5'C a 'hot' spot :-/

Did my Coopers lager at 18.5', did two wines at ~22'. Chardonnay had a blow out every day for 3 or 4 days <--- no movement?

Large trugs are cheap (<£5 @ B&Q) but, now that I've tried, tested & calibrated my heaters, I'm gonna stick with the immersion method for speed/ease of use.

If you do decide to go down the trug route, someone on here uses a fish tank pump to circulate the water in the trug, which I though was a great idea for an extra couple of quid.

It's funny though, I was so not for the immersion method way back at the start of my research. Didn't want anything touching my brew etc. Even regretted it a bit at the start of my last brew but now that I know what the units can do, my next brews will be set and forget :-)

Edit:
S***, apologies Brew Pirate, I thought mirsultankhan had posted that reply. I spent a good deal of time deciding which route to go down and though I would share my experiences.

I'm just going to nip down to my garage and prize my foot out my gob!

*I must not evaluate my products <cough> and post on forums at the same time :-/

As I was driving I was thinking about this and your reply and you are correct, I was over thinking it and thinking on a larger scale. The yeast do move though the wort but they are swimming though not circulating the wort. With thermal dynamics it will rise and that should slowly mix throughout the fv. It would be interesting to place 2 temperate sensors and see what the difference is and how they track though the fermentation process.

Funny I just ran across this image which may work out well in making sure the temperature is dispersed throughout evenly. You wouldn't need a pump which adds oxygen to the beer and let science do the work :)

I have planned at some point opening a brewery and planned on stainless coils in the fermenters to control the temp as well an external coil.

I dont have to worry about heating in California, only cooling so I wont need a heater but still a great idea.