A Great Place To Shove Your Temperature Probe

Australia & New Zealand Homebrewing Forum

Help Support Australia & New Zealand Homebrewing Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

PistolPatch

Well-Known Member
Joined
29/11/05
Messages
2,717
Reaction score
44
Wasn't too sure how to word this topic title but many of you will have had the same problem I'm having tonight...

The Problem Your tap water is around 28 degrees so that's the best you can chill to without pumps and chilled water. The best you'll chill to and this'll take 60 minutes or more is 30 degrees.

Solutions Well, I don't know any easy solutions. Let's talk ales... You can choose to not pitch, throw your fermenter in a 2 degree fridge and then wake up to find it's too cold the next day. You can also choose to pitch at 30 degrees, throw your fermenter in an 18 degree environment and find that it takes way too long to cool to acceptable fermentation temperatures.

If you have a temperature controller like I do (the MashMaster one - top stuff!) the real problem is where do you put the probe? If you put it in the wort which is the ideal place, and set it to say 18 degrees, your fridge will run non-stop for way too many hours - very inefficient. If you put it in the fridge set at 18 degrees then your wort is going to take forever to cool.

Being the first brew I have done in my new abode, I had to deal with this problem. The best I could cool my wort to was 30 degrees. I chose to pitch...

So, Here is Where I Shoved My Probe Tonight

What I've done is shoved the Mashmaster probe half-way through the fermenter lid, set it at 18 degrees and it seems to be working a treat....

The probe, after 2.5 hours, is reading 18 degrees while the real fridge temperature is 8 degrees and the compressor is therefore not continually running....

Just pulled off 250mls of wort and it is at 24.5 degrees already.

I like that. I'm out of the danger zone.

Of course the time it takes to get down to 18 will increase exponentially but I'm happy with the above result especially as I pitched at 30. Think I can now safely put Batz's Alt to bed.

Of course pitching at the right temp would be great but tonight it wasn't an option.

My goodness! There's a movie on Channel 9 and the girl in it has taken off all her clothes.

Gotta go,
Pat

P.S. Anyone else had this problem. If so, what do you do?

Christ! Thought it must be SBS but it is Ch 9!!!!
 
Just been reviewing my times whilst corresponding with brown_dog. Here's one last reading...

oil End: 9:10pm
Chill End: 10:20pm
Into Fridge: 10:45pm
First Temp Readings: 11:45am (Readings above)
Final Readings: 1:30am (As follows...)

Probe Reading = 17
Fridge Temperature = 10
Wort Temperature = 23.5

Time for bed,
Pat
 
Hey buddy looks like you and me are the only ones lurking at this time of night.

Good to see your online again.

Hows perth?



I'd just shove it in the wort..having the fridge run constantly for a while shouldn't hurt it.

I've often left the fridge door open all night after eating all the timtams in drunken stupor... and it still runs fine.

I dont think it would over-chill it either..Depends how much other stuff was in the fridge to store the cold. (if you know what i mean)



Sqyre.. :beer:
 
I wouldent worry about it buddy, The compressor in my fermenting box has been running non stop for about 2 months now. I do trun it off for an half hour once a week to defrost the coil then straight back on . It runs so hot that I had to put an old 30cm fan blowing on the compressor to help cool it as it was seizeing up underload .. But the fan stopped that and it just runs flat out ...

Oh to build my cold room.. must go to work and earn a buck..

:beer:
 
I suspend my probe in a bottle/glass of water in the fridge. Obviously the thermal mass of the glass is smaller than the fermenter and its contents, but it's better than dangling the probe in the fridge air.

It sounds like you have found a solution, I'm a bit paranoid about sticking things directly in my wort, so I use the glass trick...
 
Hi Patch

Slightly off topic but it may help your cooling problem.

I have a similar problem with the ambient water temp in Melbourne. Although its not at 30 it takes a long time to get to a reasonable pitching temp. My solution was a pre-chiller. I put it in a 4 litre bucket, fill the bucket with water and freeze it the day before brew day. I connect it only when the wort temp is down to about 35deg as I found the ice melts pretty quickly.
IMG_0753a.jpg
Its made out of 2 metres of 3/8 soft copper and if you are careful you wont need any bending tools. You could also get away with using hose clamps instead of using welded on hose tails.

It works very well but if I made it again I would double the length of copper.
 
Hi Pat,

Stick your probe in the wort, it's the best way IMHO to control your ferment accurately. Why go to all the bother of buying accurate temperature control equipment & than just measure ambient air...
You compressor will not run continually, for as the airspace cools down the fridges own thermostat will kick in intermittantly. Far better to pitch at the correct temp the following day than pitching too warm.

Bugwan - make a S/S thermowell & insert through the airlock hole of your fermenter, controlling a small bottle of water is not going to give you accurate temp control. I can ferment 2 brews in my fridge happily at temperatures 5c apart (& often do), by controling one brew & letting the other rise & fall in unison - which demonstrates the need to control the brew, not a secondary vessel...

Cheers Ross.
 
I do what ross is talkind about

I have a PT100 probe that is in the firmenting wort

I use a temperature controller to switch the fridge on and off

there ia a thermostat in the fridge that is set to a relivent temp to cut out the compressor. If you dont use this the temp controller will run the fridge non stop and freeze it up.

It works a treat, holding my brews within 0.1 deg od setpoint

and it will crash chill the wort to the desired temp and them hold it there

cheers
 
I second using a thermowell, dead easy to make with an old dip tube.

The next best thing would be to tape it to the side of the fermenter and then cover it with some sort of insulation so that it measures the fermenter temp and not the air.
 
So were in Melbourne could i get a thermowell????

and

could this just be pushed over the Fridemate probe or would it need to be permanetly fixed some other way.

Rook
 
I use two glass carboys and find it much easier to just push a bit of convoluted foam between the two carboys then push the probe into the foam against one of the carboys. Glass seems to conduct the temp quite well. Because the Fridgemate probe seems to keep identical temps to the sticky thermo on the side of the carboy.

Yep I know the temp of the fermenting wort in the carboy could be a little higher at high krausen. I sort of assume glass insulates to some degree and ferment at 2 degrees less than recommended yeast temp. Seems to work well. :)

Warren -

DSC01766.JPG
 
So were in Melbourne could i get a thermowell????

and

could this just be pushed over the Fridemate probe or would it need to be permanetly fixed some other way.

Rook

Rook

Easiest way would be to get your hands on a spare corny dip tube, cut it short, beat the end down and maybe fold it over so liquid does not seep in. Even handier if you could get the tip tig welded or similar.

From what I can gather the Fridgemate probe then just pushes down the tube with a fair degree of ease.

Warren -
 
So were in Melbourne could i get a thermowell????

and

could this just be pushed over the Fridemate probe or would it need to be permanetly fixed some other way.

Rook

Most HBS's should be able to supply a keg diptube, which makes a perfect thermowell.
If not, send me a mail & I'll sort you out.

cheers Ross
 
having the probe hard up against the outside of the fermenter with a rag to insulate it from the cold fridge air is accurate to within 1/2 a degree of the actual wort temperature for me.

I'm quite happy to let my ferment temp range from 17-19 degrees on a constant up and down cycle. Does anyone really think they could tell the difference between a beer fermented like this and a beer fermented at a constant 18 degrees?
 
No worries Ross,

i got asked what i want for my birthday last night and the first thing i asked for was not well received :p so i said i'll get some more beer stuff :D

Rook
 
Once my wort has chilled to the correct temperature I do have my probe suspended in a dip tube in the actual wort.

The reason I didn't want to do that last night was because my fridge is a converted freezer and therefore the compressor would have run continually for about 6 hours dropping the ambient fridge temp down to about minus 25 degrees - my compressor doesn't cut out until the probe temperature matches my dialled-in temperature.

For the next brew I'll be rigging up my pond pump and using a cube of chilled water to cool for that last bit. Unfortunately last night, I didn't have the right hoses - lost in transit. This seems to work as well as a pre-chiller and I already have the gear. (Nice chiller there Peels!)

Anyway, the wort is now (at 8:30am) at 19 degrees so all is well.

And if anyone wants to know what sort of beer gets you inebriated the quickest, I'm pretty sure it's whatever beer you're having while chilling.

;)
Pat
 
I use two glass carboys and find it much easier to just push a bit of convoluted foam between the two carboys then push the probe into the foam against one of the carboys. Glass seems to conduct the temp quite well. Because the Fridgemate probe seems to keep identical temps to the sticky thermo on the side of the carboy.

Yep I know the temp of the fermenting wort in the carboy could be a little higher at high krausen. I sort of assume glass insulates to some degree and ferment at 2 degrees less than recommended yeast temp. Seems to work well. :)

Warren -
You will like this Warren, run the probe through the blow off tube into the wort for better control, I gave up on the foam taped to the side of the carboy. ;)
 
Bindi do you use a thermowell with that? If not how do you stop the wort soaking the cable?

As for taping foam to the carboy side? ... Not needed with 2 carboys. B) Just push the carboys together, stuff the foam between them and push the probe against one carboy. Easy as. The other carboy works just like a big 23 litre clamp. :super:

Warren -
 
Can anyone see an issue with using aluminium tubing for a thermowell? A metre length from Bunnings costs a few dollars.

Alternatively, I guess a length of vinyl tube?
 
Back
Top