For Jamil - Brewing Classic Styles ferm. temp. help

[marnold]

Do you know the exact show?

September 4, 2005.

You can search the archives at: http://www.thebrewingnetwork.com/sundayarchive.php

[Mylo]

It has been discussed several times. In addition to the 9/4/05 - I think it is discussed on both the 11/20/05 show, as well as the 8/26/07 show (and probably others!).

IIRC, he is a big fan of the digital controls when it comes to this application. They (can) have much tighter differential setting than the analog ones - which have a 4 degree differential that is too wide for fermentation temp control. The probe is just the black plastic one that comes with either the Johnson or Ranco controls.


Mylo

[mr x]

I am an instrument mechanic and use high quality digital controls, and it makes a huge difference what kind of probe you use and how you use it. Even digital controls can easily have 2-4 degrees of error, because of sensor and controller accuracy. And even that doesn't account for measurement error from sensor placement. I use a platinum RTD which gives me accurate control down to .2 degree F. It is inserted into the carboy, so there is no thermal effects. Not that there is anything wrong with any particular method, it's consistency that matters for repeatable good beer. I'm trying to determine if JZ's 67 deg is the same as my 67 deg when it comes to fermenting my wort.

[ColdBraue]

... it makes a huge difference what kind of probe you use and how you use it....

Notice size it not mentioned, it's all in how you use it. Hehehee

[mr x]

check the temperature control show, pretty sure he tapes the temp probe to the outside of the glass carboy and surrounds that with foam.

Nice to know at least one person listens to what I say.

This temperature is the same as the beer temp.

Close, about 0.5-1.0 F difference. Checked myself and that's what I got. Closer to 1 degree f over time.

08-26-07 is the best listen.

[Brant]

Im gonna guess that jamil is anal enough to calibrate his temp controllers to the greatest extent he is capable, and then more so.

[jamilz]

Keep in mind that the higher density on the beer side (beer -> glass -> probe) is far more efficient at transferring heat to the probe than on the air side (air -> probe). And when you cover the probe with insulation, the probe ends up reading the same as the liquid on the other side of the glass. If you have any sort of beer movement (like when beer is fermenting) you're guaranteed that the temp is the same throughout.

In my opinion, there really is no need for probes in the beer. Just another way to introduce contamination and another needless expense.

[mr x]

In my opinion, there really is no need for probes in the beer. Just another way to introduce contamination and another needless expense.

Depends on how you do it. I use a platinum RTD probe, the kind that is sealed in 1/4" ss tubing - no thermowell needed (you can also make your own thermocouple probe like this). Easy to sterilize, and it fits perfect in the 1/4" hole on the carboy caps. In this way it doubles as a stir stick in-case I need to rouse my yeast, so it actually decreases my chance of infection. I say the difference between the two is closer to 1 degree f than zero, using lab quality instrumentation. But it hardly matters. I am going to start increasing my ferm temps by one degree from what is in the book and see if I get better fermentations/beer.