New larder Fridge.

[D4nny74]

Hi All

Not been on in a while , busy with new job and building brew shed , my question is , I bought a new larder fridge so I can ferment two brews at the same time , but do I do ambient air temp or got off the top fermentors thermowell temp ? any ideas will be great

[Haydnexport]

id defo go thermowell

[D4nny74]

Cheers fellas

[Andy]

Can you clarify the question ? Are you looking to use the beer or ambient temp to control something ?

If you're using an Inkbird or similar to control the fridge temperature then you need to use the ambient temp inside the fridge not a thermowell inside the fermenter.

[D4nny74]

yes, ST1000

[Andy]

OK. Don't put the probe in a thermowell then. Measure the ambient fridge temperature. The wort volume is very large and will take some time for the temperature to adjust to reflect the heating/cooling being applied. This will lead to over heating / cooling. Much better to set the ambient fridge temp and let everything settle to a common temperature over time.

[Haydnexport]

That's interesting , Id have thought the lag between ambient and liquid temp too great , i have mine, 3 working via thermowell as the heat generated by the yeast i thought would raise the temperature above ambient?

[mirana212]

[quote="D4nny74"]Hi All

Not been on in a while , busy with new job and building [url=http://www.shuttle-paris-airports.com/]paris shuttle[/url] brew shed , my question is , I bought a new larder fridge so I can ferment two brews at the same time , but do I do ambient air temp or got off the top fermentors thermowell temp ? any ideas will be great [/quote]

I think it's better if it's the ambient temperature because that's what I do for mine and it works very well.

[donchiquon]

That's interesting , Id have thought the lag between ambient and liquid temp too great , i have mine, 3 working via thermowell as the heat generated by the yeast i thought would raise the temperature above ambient?

+1 I use the thermowell during primary, after discovering that the temperature in the wort was as much as 4 degrees higher than the ambient. Then I pull the probe out once primary is finished and the yeast is too tired to heat things up!

[Aleman]

I use a fridge with my SS Chronical . . . this has a Thermowell that my BrewPi Sensor fits in really well, I get swings of +/- 0.3c During feremntation, but the fridge temp swings quite a bit more (The BrewPi has two sensors Air/Beer). OK The BrewPi may not be a good example as it uses a continually evolving PID algorithm to tune the heating and cooling parameters.

Definitely measure the beer temp

[Jambo]

OK. Don't put the probe in a thermowell then.

Disagree.

The wort volume is very large and will take some time for the temperature to adjust to reflect the heating/cooling being applied.

Exactly.

This will lead to over heating / cooling.

No it won't. The thermal mass of the air in the fridge and the cold part of the fridge body is naff all compared to that of even a modest volume of wort, so there is very little potential to overshoot by any significant amount.

Much better to set the ambient fridge temp and let everything settle to a common temperature over time.

If you don't have the luxury of a thermowell this is good enough, but when you consider that fermentation creates heat, you'll often be behind (i.e. too warm) with this approach. Without a thermowell I would suggest the poor man's equivalent of securing the temperature sensor to the outside of the fermentation vessel with bubble wrap on the outside to make it measure the FV temperature more accurately.

[AnthonyUK]

Definitely measure the wort or at least the FV.
There isn't an issue with large swings in my experience due to the thermal mass of the liquid and I did record the temps with a Raspberry Pi and graph the differences to find the best solution.

I also ferment two batches concurrently in a larder fridge and it works well as long as the recipes and yeast are similar.
I obviously wouldn't work doing a Saison and a lager

[Fil]

when considering temperature change penetration into a brew effected via the air within a brewfridge the state of the brew is an important factor,

Both at the end of primary And when first pitched the brew will be a basically still liquid unlike the brew during the few days of active fermentation when the liquor will be a stirring mass with co2 rising and having a great temperature homogenising effect.


having carried out a few rough tests applying heat via a trace cable wrapped around a vessel, and measuring how long heat takes to penetrate to the centre and any over heating recorded at the edge/wall where the change is being applied. i would suggest its always better to place any controller probes measuring temperature in close proximity to where the change is being effected, So if employing an internal hex coil bang in a thermowell to sit an inch or 2 away from the hex. and if applying change via the air in a brew fridge measure at the FV wall..

while an active fermentation will mix itself and normalise the bulk temp rapidly, a still liqour is not so efficient and if measuring the temperature far from where any change is effected the risk of over applying any change is drastically increased.

in the case of 2 x bins in a larder fridge and the same target temp i would suggest invest in 2 fans to ensure the air movement is rapid to both normalise the internal temp an effect the most efficient hex possible, and have the probe guaging the fridge air. it will promote both brews to tend towards the target temp without over reaching in either direction.

[D4nny74]

Cheers guys , nearly have the new brewshed finished so looking forward to getting a brew on

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[Fil]

PHWOOAARRRR!!!!!

Runcorn Eh?? well til now ive had no call to visit..