TEMPERATURE CONTROL

[zx7rtas]

What is the most effective way to keep my brew at the right temp.I usually use a thermostatically controlled immersion heater at 24 to 26 deg.Now since visiting this forum i am told that a range of 18 to 22 deg is better. I have read that an old fridge can be used in some sort of way .How can i acheive this

[timmy]

You can get a temp controller for about $60 that will run the fridge at whatever temp you set (it basically switches the fridge off when it gets to the temp you want).

It is the easiest way but a cheapo way is to immerse the fermenter in a tub of water and add ice if needed. I freeze a few Coke bottles full of water and then rotate them.

[Bizier]

Most people here will be using a thermostat/probe device called a Fridgemate that cuts a fridge in and out. You need to wire it up or get someone to do it for you - and this is 240v we are talking about, so be scared. But then you plug the Fridgemate into the wall, and plug your fridge into this, and set the temperature with the probe in the fridge... you will never look back.

I got mine from Ross at Craftbrewer, and think that it is probably the best thing I have done for my beer to date. I also have a very large fridge that can fit 2 fermenters, and possibly a third if I build a shelf. The only limitation is that I need to apply the same settings to both batches, so I try to use similar recipes and yeast strains.

There is also a better, newer model called a Tempmate that controls 2 circuits, one for cooling and one for heating. I would like this very much because it holds a steadier temp.

Hope that this helps.

[warra48]

I endorse what Bizier said.

I use a TempMate, and it holds the temperature within .5ºC of the set temperature.
You can plug in your fridge and also a heating element such as a pad or belt, and it will switch from one to the other automatically as needed.

I highly recommend the TempMate.

[billybushcook]

I'm going through a similar thing at the moment,
I have been using a fishtank heater in the bottom of my brew for 16yrs & works great if you can keep the atmosphere around it just below the desired brew temp by using frozen bottles of water in summer. the fermenter (or two) along with a full batch of bottles all fit in an old chest/deep freezer.



I am now looking at the "tempmate" to make my system fully automated, the brew box sits right beside my beer fridge so I can set a little pond pump in the crisper section of the fridge, fill with water & use the Tempmate to automatically cut the pump in & out to circulate cold water through some copper coils in the brew box, (instead of having to use another fridge) I prefer the open top style & space of a chest freezer any way.
Instead of the submersion heater I will use a light bulb in an empty concentrate can for heating, .....easy, set it & forget it!



Tempmate wiring diagram



So, as others have said, the Tempmate will automatically kick in either heating cycle or cooling cycle to keep the brew box at whatever temp you set it at.

There is a good thread on it here,
http://www.aussiehomebrewer.com/forum/i ... ntry367165
you will have to sign up to see the pics!!

Cheers, Mick.

[Bizier]

I use a TempMate, and it holds the temperature within .5ºC of the set temperature.

Yep, the Tempmate was released about 5 minutes after I got my Fridgemate.

The limitation of my one is that it chills, but the only warming comes from the exothermic actions of fermenting yeast, and the ambient temp outside the fridge. So sometimes it will over cool my beer, which I am not super keen on. I find that the actual working temp is about 2 degrees either side (including "on time"), which is too much variation for my comfort. I have been experimenting with probe placement and have worked out some tricks with a little help from my friends (AHB) to reduce temp shock.

The extra $25 is very well spent if you want to get better control of your yeast behaviour. And we all should want that.

[Rob C]

Bizier i also use a fridge mate. Where abouts do you place your probe? I have been placing my prob to measure the ambient fridge temp not the fermenting beer. As the fridge changes up and down in temp i gather the beer should stay pretty stable.

Cheers
Rob

[Bizier]

I have tried under the fermenter, on top unter my blowoff tube bottle, stuck between 2 fermenters sealed with blutack, and now I have just strapped it on the side under a HD foam block. Looks like something from 2001 A Space Odyssey.

Here is a pic:

[billybushcook]

Finished off my brew box heating & cooling systems yesterday, ready to plug the temp mate in when I get it boxed up,
The heater is simply a blacked out "bunker" light so it is humidity proof.


& for cooling I put a 2.5W pond pump in the crisper of the beer fridge (right next to the brew box)


& yes the fridge does need a clean out.....
The water is pumped through an old airconditioner heat exchanger (radiator)


The box even scored it self a nice new shiney lid


This way I don't need an extra fridge, just use the cold from my beer fridge!!

Cheers, Mick.

[drsmurto]

Bizier, the problem you face is that you are measuring the temperature of air rather than a liquid.

Whilst the temp of the air inside your fridge may vary up and down relatively fast the same cant be said for the fermenting beer. Every time i open my keg fridge up the temp on the fridgemate changes due to air movement. the temperature of the beer in my kegs doesn't change (unless you can measure 0.0000000001 of a degC)

try filling a 2L bottle with water and sitting the probe in that. You will find the temp fluctuations much less. I start off with a thermometer in a flask of water to check the temp of the fridge over the first few days of ferment just to check how close it is to what the fridgemate is telling me. I then adjust the setting on the fridgemate up or down accordingly.

I wont go into the science behind it......

[Bizier]

I dig, I dig.

I think that when I placed it underneath, I was getting an interference from the temperature probe touching floor of the fridge. The HD foam method is keeping a very stable reading (no change of display noticed yet).

I like that this keeps the exothermic properties of yeast in check too, sometimes they get a bit excited, the little buggers.

[billybushcook]

Same reason I have always had a good result with the submersion heater (in the brew), The thermostat is reacting directly to the temp of the liquid I'm trying to ferment & all I had to do is keep the box just slightly lower & the thermostat did the rest.

Fired up the "Temp mate" today & must say ......I wish I'd had this years ago...Just set it & forget it........Today got back up into the 30's here after a week of wet, windy days in the low twenties & It worked a treat, as the day got hotter & the yeast kicked into high gear (generating heat on day 2) it kept bringing the pump on line spot on to keep up with it, got the differencial sorted so heat & cool were'nt fighting each other & it settled the box & contents to exactly what I had set.

The difference is though,
I'm now monitoring & adjusting the box/ambient temp as you guys are saying, but my thermocouple/probe is set central to both heating (bottom) & cooling (top), both using convection to circulate air, one down & one up.

As I see it, the trick with this is to anticipate the brew temp over the ambient.
ie, set the box 2 deg below when the yeast is going hard (first 2-3 days) & then bring it up to the brew temp until dead, then you can even dial it down to cold condition, although last batch of bottles would have to be removed by then!

Cheers, Mick.