Fermentation question

[Palazar]

I made a post a couple of days ago concerning my first brew this is a little related. When I first pitched my yeast, the little temp strip on my primary showed about 70 degrees. However over the past two days, I noticed that the strip has been showing dropping temps and is as of now, at 66 degrees (2 degrees per day). My house is at a constant 70 right now so it can't be that right?

I've put my thermometer right against the fermentor and covered it and the lowest it read was 70.8

 

[adiochiro3]

Those thermo strips are often suspect IMHO. All thermometers are suspect until proven accurate by boiling and/or freezing or in comparison to a thermo that is already proven accurate by boiling and/or freezing. Check your strip against a verified thermo and adjust your interpretation accordingly.

 

[Curtis2010]

Thermostrips do not give you an accurate temp of the liquid inside the fermentor, which is whats important, esp if the frementor is the typical thermally inefficient plastic bucket to which they are often adheared.

Chuck the strip. Use a known good thermo (calibrated) and test temp of a wort sample directly.

 

[Palazar]

Ok I'll do that. Thanks again guys

 

[dirtfang]

Are Thermo strips really that bad? I mean a few degrees off isn't going to make that much but difference is it? I assume that the Thermo strips would be a lot better than opening up your fermenter to check the temperature on a regular basis. Right?

 

[dickproenneke]

I routinely use those strips on my plastic bucket fermenters and have always found them to be fairly reliable and accurate. I always keep several on hand to monitor ambient temps as well as my fermentations.

 

[Curtis2010]

I routinely use those strips on my plastic bucket fermenters and have always found them to be fairly reliable and accurate. I always keep several on hand to monitor ambient temps as well as my fermentations.

Have you compared their readings to actual wort temps?

 

[dickproenneke]

Have you compared their readings to actual wort temps?

Yes. And I've never seen more than a 1 degree difference

 

[Curtis2010]

Yes. And I've never seen more than a 1 degree difference

Surprising result given that they are out in ambient temps on the side of a not very thermally conductive plastic bucket.

 

[dickproenneke]

Surprising result given that they are out in ambient temps on the side of a not very thermally conductive plastic bucket.

I suppose if you ferment in a very hot or very cold room then there would be a greater variance in the temp reading. But in my case, my basement brewery is always within 10 deg of my ferm temps - not really enough to influence the strip by much. Here's an thread from a fellow HBT'ers experiment on the topic.
https://www.homebrewtalk.com/f11/ever-wonder-about-those-stick-thermometers-278143/

 

[Curtis2010]

I suppose if you ferment in a very hot or very cold room then there would be a greater variance in the temp reading. But in my case, my basement brewery is always within 10 deg of my ferm temps - not really enough to influence the strip by much. Here's an thread from a fellow HBT'ers experiment on the topic.
https://www.homebrewtalk.com/f11/ever-wonder-about-those-stick-thermometers-278143/

Interesting. Learn something every day. I've always been suspect of them for brewing use, but I guess if given enough time, and not a big delta from ambient, the plastic will settle in to a temp very close to the wort.

Of course, I've even had fancy thermos drift, but they can be calibrated.

Part of what keeps hobbies like this interesting, always more to learn.

 

[cjgenever]

Used those for a few years. They were always more accurate with glass. The time temp is most critical is during primary ferm since our can quickly gain temp on its own. they just don't respond fast enough for comfort. I used to tape a flap of insulation over mine to help with that. You can make good beer with them if you know what to expect from the ferment and/or watch out continuously. You can make great beer CONSISTENTLY with an inexpensive temperature controller.