Tall Larder fridge fermentation issues - ideas

[musojohn]

I have a larder fridge and attempted my my 1st 10 gallon brew on Thursday.
Pale Ale . 1.048 OG. Loads of EKG.
I thought I'd try something new and tried Windsor in one and gervin in the other.

Is there a good place to put the temperature probe to get a good/ balanced reading, or is it asking too much of the fridge/probe?

I'm having mega issues and both appear to have stuck around 1.026.

(The gervin did not start at all and when I checked the temp it was at 16.7 with no activity after 24hrs. Also it had a slight off smell when I re-hydrated it, but it was the 1st time a have used it. I threw in a packet of SO4 and moved the heating 16kw element to the top shelf to get the temp up. There was a krasusen going the following morning.
The Windsor went off like a rocket but when I moved the heating element I came back to it and all -vigorous- bubbling stopped and the Cedaroincs controller was showing at 18.7C with the probe attached under 3 layers of bubble wrap to that fermenter , but the beer at 16.8C !? After giving both a mild thrashing there seems to be nothing doing)
The Windsor is also quite sulphurous , which elsewhere Critch suggested can happen.
Any suggestions ?

[Matt12398]

Attaching to the side of the fermenter, under some insulation and not to close to the heater is one of the best options to get it reading a temperature close to that of your wort temp. What are you measuring the beer temperature with? Is this thermometer accurate? If not it could be that your beer is at the right temp. If it is then possibly you need to reconfigure your temp controller.

[musojohn]

yeah to be fair i made a few mistakes with this. The tube heater was next to the - lower - fermenter near the probe as i was concerned that the heat wasn't getting through the glass shelf, so this probably accounts for the difference.

It was the 1st time using both yeasts but i mashed in at 67-68 so finishing at 1.020 (which it is now down to) doesn't seem too at odds with what i've read. viewtopic.php?f=24&t=53094. I'd mash lower next time.

Any ideas on how best to manage controlling 2 fermeters with different yeasts ?

[mark4newman]

Hi

Put the probe into the middle of the wort. It is about the only place that will give you a true reading. Sticking to the outside obviously gets over any infection problems, however you will probably be reading low. I've done comparisons, and the temp diff can be up to 5C between the center and the outside.

However, only do this if you are confident in your cleaning/sterilising

FWIW, I have the probe in the middle of the wort, and use a brewbelt on the bottom of the fermentor. I find this works well, as air is a poor conductor of heat.

[AnthonyUK]

In a tall fridge you may need a couple of small PC type fans connected to the heating and cooling circuits to circulate the air and equalise the temperature.
Also ensure that your shelves allow air to flow.

[musojohn]

Thanks for tips. I think all the heat went to the top as reading on that one was 22C, so big difference between the 2. I also need to build some shelving rather than using the existing glass on lower and plastic on upper.

[barneey]

Hi

Put the probe into the middle of the wort. It is about the only place that will give you a true reading. Sticking to the outside obviously gets over any infection problems, however you will probably be reading low. I've done comparisons, and the temp diff can be up to 5C between the center and the outside.

However, only do this if you are confident in your cleaning/sterilising

FWIW, I have the probe in the middle of the wort, and use a brewbelt on the bottom of the fermentor. I find this works well, as air is a poor conductor of heat.

+1 actually measure the wort temp for the best results, depending on your batch size there is quite abit of thermal mass in the fermenting liquid.

[musojohn]

'Put the probe into the middle of the wort. It is about the only place that will give you a true reading.'

How would that affect the different wort in the other fermenter with different yeast ?

[AnthonyUK]

From my limited testing, measuring anything but the wort at the start of fermentation will be unreliable.
If you measure the air or a second small volume of liquid I would compensate by setting your set point to 3-4°c below what you require for 24-48 hrs and then increase to your actual setpoint.

Here is my recording of a simple experiment.
The beer turned out fine BTW even at these temps.

This is still going to be better than most peoples temp control who are happy with their results.

[darkonnis]

Putting a sponge over your probe on the outside of your fermenter greatly reduces the air in the fridge giving you false readings.
Works for me atleast.

Anthony, what software you using to produce that data?

[AnthonyUK]

It is raspberry pi running Linux with a Temper2 USB sensor from eBay.
The logging is via RRD and the graphing is RRDTOOL.

You could use anything capable of running Linux though TBH or even windows such as an old laptop.

[musojohn]

I'm really trying to work out how best to run 2 fermenters with only 1 probe, not measure wort temp.

[AnthonyUK]

MusoJohn - You are obviously starting both batches together otherwise this would be impossible.

I put the probe in a small amount of liquid e.g. half a bottle of water, to smooth out the temp changes.
If you have a couple of fans then the temperture should stabilise pretty quickly.
Once the initial ferment activity is over temp control is straightforward as you only have ambient variations to contend with.

[darkonnis]

I just measured one of the FV's I use a heat belt on one and an under tray heater on the other. Seemed to work really well for me.

Might have to give that a go anth ty

[AnthonyUK]

Might have to give that a go anthony

If you do go with the RasPi you are more than welcome to a copy of my SD card image
I'm hoping to move away from the USB sensor to a DS18B20 as you can daisy-chain as many as you need.



There are also waterproof versions



These are really low priced and easy to interface with the Raspi.