Really strange temperature issue

My wort has been fermenting in my living room for 3 days. I had my house heat on a steady 70 degrees all day today. Came home and my fermometer reading dropped from 66 to 62/61. I really don't understand how this possible. Unless my heat or home thermostat isn't functioning properly or my fermometer is not correct...

is the thermostat RIGHT by the carboy? my thermostat reads 69, but if i use a laser temp reader, the area i'm sitting in reads 65, 15 feet away from the thermostat.

Heat rises. If your ducts are in the ceiling, or not near your Carboy, your thermometer is probably right.


I wouldn't worry though. If you started at 66ish, your beer probably reached 70 during fermentation (yeast causes wort to increase about 5 degrees during fermentation). Once the first few days of fermentation pass, the yeast won't really create any off flavors if the temp changed.

That, plus 62 isn't bad at all. A little low for initial fermentation depending on the yeast strain, but it's not too far. You should be fine.

ghank15 said:

Heat rises. If your ducts are in the ceiling, or not near your Carboy, your thermometer is probably right.

THIS^^^^^

That, plus 62 isn't bad at all. A little low for initial fermentation depending on the yeast strain, but it's not too far. You should be fine.

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i ferment almost all my ales at 62, pitch at 62, it's a great temp for most strains.

Oh wow. Turns out the Fermometer is grossly off! Opened up and took a sample to test temp And SG. The sample temp was 68... The fermometer still read 62ish. I cooled it a little. The SG right now after 3 days is 1.0209 with an expected of 1.011-1.007. Looking good so far. Didn't taste it, smelled kinda sulphor-like.

Sulfur is a normal type of smell for fermentation, although I believe lagers smell more like sulfur than ales. I'm not sure about this.

I definitely wouldn't worry about the smell, most smells from the primary don't make it into the finished product.

ghank15 said:

Sulfur is a normal type of smell for fermentation, although I believe lagers smell more like sulfur than ales. I'm not sure about this.

I definitely wouldn't worry about the smell, most smells from the primary don't make it into the finished product.

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Thank you. I didn't mean to sound as if I was concerned about the smell. It's just that is what turned me off from the idea of actually tasting it

Thanks to all who replied. Given the incredible discrepancy between the ambient temp, the wort sample temp, and the temp shown by the fermometer, I can only conclude that my fermometer is defective... it's nearly TEN degrees off from what thermometer showed in the sample. I will get a new fermometer today and put it on the bucket right next to the old one and see if they show the same temp.

I know that temps can vary a lot in a house from what he thermostat reads, but not 10 degrees. Also, it's pretty obvious to me that is not 60 degrees in the room where my fermenter is. Again, I can only assume/hope that my fermometer is given a bogus reading. I assume these are usually accurate and that's why they are commonly used? Is there something better I should replace it with?

Ok... so now I am very confused.

Came home tonight and the fermometer said 60. I had a new fermometer with me. I applied that one to the bucket as well. After an hour I checked that one and they both read close to the same... one was about 60, the other about 60-61 depending on interpretation of the squares. I also had a digital ambient thermometer with me too. I checked the air temp in the area around the fermenter - it was 60 also. So now that much was starting to make sense. Although... I took a sample of the wort, checked gravity and temp. The gravity is the same it was 24 hours ago. The temp is the weird thing. When I used my brewing thermometer



it said the actual wort sample temp was 68 deg. I don't get it....

I also tasted the sample and it tasted sort of sulfuric. Smelled and tasted a little like flat beer but had a fairly unpleasant taste. It's been about 4 days now in the fermenter.

J187 said:

Ok... so now I am very confused.

Came home tonight and the fermometer said 60. I had a new fermometer with me. I applied that one to the bucket as well. After an hour I checked that one and they both read close to the same... one was about 60, the other about 60-61 depending on interpretation of the squares. I also had a digital ambient thermometer with me too. I checked the air temp in the area around the fermenter - it was 60 also. So now that much was starting to make sense. Although... I took a sample of the wort, checked gravity and temp. The gravity is the same it was 24 hours ago. The temp is the weird thing. When I used my brewing thermometer

it said the actual wort sample temp was 68 deg. I don't get it....

I also tasted the sample and it tasted sort of sulfuric. Smelled and tasted a little like flat beer but had a fairly unpleasant taste. It's been about 4 days now in the fermenter.

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those fermometer's are horribly inaccurate by nature, as you can see when an accurate thermometer is used to take the same temp.

Hmmm. It didn't seem like they would be the most accurate thing ever, but that's so far off they are virtually useless. What is a better way to monitor temps? Should I be concerned my ale has a sulphuric taste and smell after 4 days? I'm
Reading some bad things about bacterial infection.

How do you know it is the fermometer??? You have 2 that agree and a dial thermometer that does not. I suspect the dial one is off.

At 4 days your fermentation is a long way from being done I would not worry for another couple of weeks. I have had some that did not taste great on bottling day. 2 weeks later - fantastic.

Patience grasshopper!

By measuring the ambient air temp and the temp of the fermenter you are measuring just that. To get an accurate reading you really need to measure the temp of the liquid during fermentation.

Beer is a living food which produces its own heat during the fermentation cycle. The yeast cells are in there mowing through all the simple sugars, and each cell turns into a little furnace. With all that activity the beer is typically 8-10 degrees warmer than your ambient air.

I use a fermowell on my conicals, and normally the ambient air temp in the freezer is 52 degrees. The reading on my fermowell is 59* which is right where I like to keep my ales until I gradually bring them up for the diacytal/aceda rest.

That REALLY confuses me . If fermometers are so horribly inaccurate, what does everyone use to know if their temps are in the right range?

It's not that your fermometers are THAT inaccurate. They are measuring the temp of the bucket and the ambient air. As stated above, these are not the temps you want to really be concerned with. It's the temp of the liquid that really matters.

http://morebeer.com/view_product/6666/102282/5_Gallon_Hood_Thermowell_also_3_and_6_gallon

That is what a lot of carboy brewers in a couple of my clubs use.

http://morebeer.com/view_product/10958/102282/The_Graham_Box_Control_Unit

That is what I use on my conicals since they have a thermowell on them.

The webpage for the fermometer:
Products
shows how the reading is affected by ambient temperature. The info in this literature still doesn't explain the differences you are seeing, but it's worth reading.

I have a controlled chamber that I ferment in but if I'm pressed for space and I bring some into a room I take one of THEESE and tape the probe to the side of the bucket.
To be real accurate you can tape some insulation over that ,
Insulation can be a paper towel folded up, ETC....
BAH, Try this link HERE . I use 'em for everything.

squirrelly said:

It's not that your fermometers are THAT inaccurate. They are measuring the temp of the bucket and the ambient air. As stated above, these are not the temps you want to really be concerned with. It's the temp of the liquid that really matters.

5 Gallon Hood Thermowell (also 3 and 6 gallon) | MoreBeer

That is what a lot of carboy brewers in a couple of my clubs use.

The Graham Box Control Unit | MoreBeer

That is what I use on my conicals since they have a thermowell on them.

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Right, I guess what I mean is that they are not inaccurate as far as being a thermometer, rather they are inaccurate as indicators of the actual wort temp. Presently, I'm using a fermenting bucket and not a carboy. That seems like it would work great for a carboy. Thank you for the links!

ncbrewer said:

The webpage for the fermometer:
Products
shows how the reading is affected by ambient temperature. The info in this literature still doesn't explain the differences you are seeing, but it's worth reading.

Click to expand...

Thanks. I'll read it in a few minutes. I guess I didn't realize the fermometer strips were not a good indication of wort temp and I thought from what I've been reading that most people used them effectively.