A good temp before fermenting begins with wl029

[jrusso]

I'm a noob. I'm on my second brew and it's a Brewers Best Kolsch. I bought the WL029 yeast to go along with it. Here's where i'm a bit mixed up though. My Fermometer reads between 72-74, while I have the Bucket sitting in a cooler with water at about 62-64 degrees. The water is filled up to the 4 gallon mark on a 6 1/2 gallon bucket. The temp in the house is 76. No shirt or towel on the bucket. I read on the WL website that the temp before fermenting actually starts needs to be 70-75, and then you can drop it lower after it begins. My question is, does my reading so far look ok for this range or do I need to do something more?

 

[HibsMax]

I would trust what your fermometer says and it sounds like you're right in the range. Your wort temperature will be about the same as what your fermometer reads, maybe a degree or two higher. Your water, 62 degrees, will help buffer your wort against temperature changes.

 

[jrusso]

Nice. Thanks for the reply.

 

[seafra]

Fermentometer strips are fairly useless on a plastic bucket. They are reading more of the ambient temperature than the internal temp of the wort/beer...and internal is the only temp that matters. Plastic is a good thermal insulator, so there is not a sufficient transfer of energy to the outside of a bucket to take an accurate reading. Thermometer strips are a bit more accurate through glass and are much more reliable on steel; however, I've measured 7 degrees F difference between the internal temp of a fermenting Corny keg and a Fermentometer strip. The internal temp was taken with a Fluke 52-2 thermocouple thermometer.

 

[duboman]

Fermentometer strips are fairly useless on a plastic bucket. They are reading more of the ambient temperature than the internal temp of the wort/beer...and internal is the only temp that matters. Plastic is a good thermal insulator, so there is not a sufficient transfer of energy to the outside of a bucket to take an accurate reading. Thermometer strips are a bit more accurate through glass and are much more reliable on steel; however, I've measured 7 degrees F difference between the internal temp of a fermenting Corny keg and a Fermentometer strip. The internal temp was taken with a Fluke 52-2 thermocouple thermometer.

I'll politely disagree on this, I've taken internal temps on my buckets and compared to my temp strip and have noted only a 1-2 degree difference.

 

[HibsMax]

I'll politely disagree on this, I've taken internal temps on my buckets and compared to my temp strip and have noted only a 1-2 degree difference.

+1

I was so unsure about temps (ambient vs fermometer vs internal) so I did some tests myself and my conclusion was that I could trust what my fermometer says. To begin with I was thinking that if my fermometer was showing 65 that my internal temp could be as high as 75 but I didn't find that to be true. All I did was fill my bucket with 5 gallons of warm water and leave it for a while. I measured the temp with a thermometer and compared that with the fermometer and the readings were the close.

 

[seafra]

+1

I was so unsure about temps (ambient vs fermometer vs internal) so I did some tests myself and my conclusion was that I could trust what my fermometer says. To begin with I was thinking that if my fermometer was showing 65 that my internal temp could be as high as 75 but I didn't find that to be true. All I did was fill my bucket with 5 gallons of warm water and leave it for a while. I measured the temp with a thermometer and compared that with the fermometer and the readings were the close.

Hey, if it works for you, go with it and don't worry about some egghead like me. But, as I am an argumentative arse, let me point out some errors in your experiment.

In your experiment, you didn't measure and correlate the important variable of ambient temperature? If the temp of the warm water in your bucket was consistently near ambient temp, you should get consistently close readings. Additionally, if the temperature differential fell within the margin of error of the Fementometer, your reading would remain somewhat accurate while the water and air temperatures remained fairly static. However, it is when one or both of the independent variables (wort and/or air temp) change that you can draw a conclusion about the dependent variable (i.e. the reliability of a Fementometer in representing wort temp).

Also, there would be a point at which the two different thermometers (wort and Fermentometer) would cross each and even be identical. This does not mean Fermentometers are consistently reliable across a range of varying temperatures, just that it had an accurate reading at some point in time...even a broken clock is correct twice a day.

Another thing about your experiment was that you said, "All I did was fill my bucket with 5 gallons of warm water and leave it for a while." Not putting the lid on the bucket could have allowed warm moist air to surround the Fermentometer and flawed the experiment.

Yet another variable that your experiment was lacking was a varying internal heat source that would account for the varying exothermic activity of yeast. Before or after primary fermentation a Fermentometer could be fairly reliable. Nonetheless, it is during primary that we are most concerned with wort temperature and the inaccuracy of a Fermentometer can be at its' greatest.

I recommend that you measure the temperature differences throughout an entire fermentation process, paying particular attention to primary, and also measure, log and correlate the ambient temperature with the Wort thermometer and Fermentometer. If you are measuring an ale, you should use an accurate probe that remains in the top 1/3 of the wort and is in the center of the bucket. With top cropping ale yeasts, this can be your hottest thermal layer. Additionally, it would be useful to make note of and keep the air circulation consistent, as this variable will effect how much of the heat radiating from the bucket will remain around the Fermentometer and effect it.

Look forward to hearing the results. And, sorry for being such an arse.

 

[HibsMax]

Hey, if it works for you, go with it and don't worry about some egghead like me. But, as I am an argumentative arse, let me point out some errors in your experiment.

lol. There's nothing wrong with a little bit of argument. I acknowledge that my experiment was hardly scientific, it's just something that I did on a whim. My proper experiment will be with a thermowell so that I can measure ambient, external fermometer and internal wort temperatures accurately.

In your experiment, you didn't measure and correlate the important variable of ambient temperature?

Yes, in a more scientific experiment I would do a lot of things differently. I would use wort for a kickoff. The experiment I ran took me less than an hour. If I gave the impression that I was presenting ironclad results then I apologise for that.

Another thing about your experiment was that you said, "All I did was fill my bucket with 5 gallons of warm water and leave it for a while." Not putting the lid on the bucket could have allowed warm moist air to surround the Fermentometer and flawed the experiment.

That was a mistake in my post. The fermentation bucket was sealed up just like it normally is.

Yet another variable that your experiment was lacking was a varying internal heat source that would account for the varying exothermic activity of yeast. Before or after primary fermentation a Fermentometer could be fairly reliable. Nonetheless, it is during primary that we are most concerned with wort temperature and the inaccuracy of a Fermentometer can be at its' greatest.

Again, all I can say is it was a little experiment, not something I was trying to pass off as indisputable evidence. I understand that fermentation is exothermic but other reading I have done suggests that during fermentation the temperature of the wort is pretty consistent because of the movement / activity inside the bucket. It's not like you have a "ball of heat" in the middle of your wort. Now my experiment did not prove that but hopefully a future experiment will (more on that later).

Look forward to hearing the results. And, sorry for being such an arse.

I've been on many forums in my lifetime and I can assure you that you sound anything other than an arse.




My plan, should I get around to it would be to do much of what you suggested. I would ferment an ale just like normal but I would have :
1. four thermometers around the bucket,
2. four fermometers on the bucket,
3. two thermowells - one in the center, one near the side (both at the same depth)
4. record the temperatures as routinely as my time permits.

That seems like a lot of overkill but there are lots of fail safes in place, I believe. Will I get around to it? That depends on if I can build my thermowells. I have the SS tubing. I have a design from the DIY forum to make a copper well. I just need to figure out a way to make them work together.