Should I trust my brewfridge?

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Battleaxe

Should I trust my brewfridge?

Post by Battleaxe » Thu Apr 07, 2016 10:16 pm

A few weeks ago I acquired a fridge and bought an Inkbird 308 temp controller and created my brewfridge. I tested it with a Demijohn filled with water thermometer submerged inside and attached the probe from the Inkbird to the outside under some insulation they both read the same temps for 3 days,

Currently I have 5lts of Amarillo pale in one demijohn and I have a further 2 demijohns filled with a Mild manners ale both at the 3lt mark.

The Amarillo pale has the Inkbird probe attached it's showing 18c as expected but the mild manners (opposite side of the fridge) is showing 19c with the thermometer... How accurate are the temps when you don't immerse the probe? Can it be trusted im worried I have 18c shown but it's 19c in the demijohn or even worse less than 18c and I'm making the yeast hibernate... I've had all the signs of fermentation Though...

Also my Mild ale is only 3% and fermentation showed little activity and handly any Krausen is this normal for low ABV ales

lord groan
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Re: Should I trust my brewfridge?

Post by lord groan » Thu Apr 07, 2016 11:09 pm

Yes trust it. You will always get temperature variations depending when and where you take the readings, just opening the door will trigger changes in air temp, but not so quickly in liquids. Don't forget digital readings which measure to one degree are by their nature rounding up or down to a single degree so an actual temp of say 18.5might round to 19 or even to 18. If you're only getting a variation of one degree I'd be very pleased with that. Don't get hung up on trying to get absolutely exact temps, just look at how the fermentation is going - if it looks and smells right it is right

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orlando
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Re: Should I trust my brewfridge?

Post by orlando » Fri Apr 08, 2016 7:28 am

If the beers are a different stages of fermenting it could also be that the yeast is generating heat and there is inevitably a lag between the temperature in the beer and how quickly the air temperature in the fridge can trigger a change.
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Kev888
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Re: Should I trust my brewfridge?

Post by Kev888 » Fri Apr 08, 2016 8:54 am

There are numerous reasons why this may be, a (not exhaustive) list may include things such as these:
  • Unless your measuring devices (the thermometer and inkbird) are both accurate to less than +/_ half a degree, then they could easily read 1c difference at the same temperature.
  • There can/will be a slightly different temperature at different places/heights within the fermenters, and ditto in the fridge itself. When the yeast is working, some say that the activity can help to mix things up more, and you could add a small computer-type fan to the fridge to help evenness and heat transfer of the air (if you haven't already).
  • The yeast generate heat as they work, so can raise the temperature during the vigorous stages; with different fermentations but only one fridge/controller you cannot control them individually.
  • Different volumes of wort have different thermal masses so will take different amounts of time to respond to the air temperature; when you measure can therefore affect the readings.
But all that said, really don't worry; a degree makes very little difference and with all the possible causes its actually pretty good. Compare that with fermenting under no temperature control and the improvement is enormous. You'll also likely find that consistency is pretty good too, so you'll be able to refine/tweak the settings to your preferences.
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Re: Should I trust my brewfridge?

Post by Battleaxe » Fri Apr 08, 2016 9:06 am

Oh ok I will just leave it as it is! having a brewfridge is like Christmas! I suppose I've never worried about the accuracy before, it was just a case of find somewhere in the house that's roughly 18c and leave my demijohn there!

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Normski
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Re: Should I trust my brewfridge?

Post by Normski » Fri Apr 08, 2016 3:48 pm

If you put the temp prob in a bottle of water or starsan it may help keep it a wee bit more stable. But as has ben said 1c is ok.
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Battleaxe

Re: Should I trust my brewfridge?

Post by Battleaxe » Fri Apr 08, 2016 9:28 pm

Normski wrote:If you put the temp prob in a bottle of water or starsan it may help keep it a wee bit more stable. But as has ben said 1c is ok.

Shut the front door!

That is a brilliant idea! Obviously it wouldn't hell being a smaller thermal mass to cool or heat?

But it would give a very honest reading!

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Re: Should I trust my brewfridge?

Post by orlando » Sat Apr 09, 2016 6:33 am

Tape it to the side of the FV under bubble wrap. KISS,there's really no need to over egg this. :D
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Re: Should I trust my brewfridge?

Post by Clibit » Sat Apr 09, 2016 9:11 am

I found my best mate's oatmeal stout in my brew fridge.

I'll never be able to trust a brew fridge again.

gobuchul

Re: Should I trust my brewfridge?

Post by gobuchul » Sat Apr 09, 2016 9:25 am

I just use blu-tack to stick the sensor to the FV.

Seems to work fine.

marinali29

Re: Should I trust my brewfridge?

Post by marinali29 » Tue Apr 12, 2016 11:53 am

If anyone want need a more accurate temperature, I think PID controller will do better.

Also, for the temperature sensor, it was stick on the FV, so it's normal that there's temperature differences between the reading on the controller and the temperature of your beer. Maybe you can have a long sensor, which is IP68, you can put it into your beer directly.

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Re: Should I trust my brewfridge?

Post by Midlife » Wed Apr 13, 2016 8:59 pm

Yes trust it, big step forward in my brewing was stable temprature.

Battleaxe

Re: Should I trust my brewfridge?

Post by Battleaxe » Wed Apr 13, 2016 10:14 pm

Of all the things I've read or spoken about the one thing experienced Brewers always mention is "stable" temperature they never say Accurate to within 0.1C.

And they've all said its the one thing they've done that's made the biggest difference to the beer they've brewed. My first brew in the fridge is an Amarillo SmaSh and it's also the first brew I've tried adjusting my water with so hopefully I will notice a bigger difference!

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Re: Should I trust my brewfridge?

Post by Fil » Thu Apr 14, 2016 12:27 pm

Battleaxe wrote:Of all the things I've read or spoken about the one thing experienced Brewers always mention is "stable" temperature they never say Accurate to within 0.1C.

And they've all said its the one thing they've done that's made the biggest difference to the beer they've brewed. My first brew in the fridge is an Amarillo SmaSh and it's also the first brew I've tried adjusting my water with so hopefully I will notice a bigger difference!
Yep thats the accepted wisdom;) grab all your thermometers and conduct a 2point calibration test on them all using water at close to 0C and close to 100C (full details can be found in the eti thermapen manual, google "eti thermapen manual pdf" and look at pages 16.17.18 iirc)
if you have 20 devices i lay odds no two match readings 100% to 2 decimal places..

A stable temp with minimal variations will keep the yeast from reacting to varying temps which should allow for a cleaner faster primary fermentation, I find when using most yeasts that primary completes within a week regular as clockwork when using the fridge.
ist update for months n months..
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