Fluctuating ambient temperature bad?

So I got a johnson A19 temperature controller, and this thing just does not hold a temperature.

I have it set to 64 degrees. The ambient temperature gets up to about 70 before it kicks on then it drops down to 60 before it stops..

It stays at 68 - 70 degrees for a good amount of time and 60-64 for a decent amount of time too..

So on an average it's not bad, but just wondering if my beer is going to be bad because of this.

This is my first batch I should add. Had a suggestion to insulate the temperature sensor and attach to my keg, but not going to have time to get the supplies for that for a couple of days due to work.

 

It's the beer temperature that needs to be controlled - you're measuring the ambient. I don't use a fermentation chamber, but typically the probe is stuck on the outside of the fermenter with insulation over it. But with your controller not working right, it wouldn't help anyway. Maybe somebody else can help with tuning the controller.

Your 10 degree temperature swing is far from ideal, but I can't say from experience how it will affect the beer. I'll bet it will still be ok - time will tell.

 

Couple of things. Make sure your probe is taped or insulated to your fermentation container. You should also look into the manual. Your really shouldn't be swinging that much. You should be able to set the temp down to 1 or 2 degree fluctuation. There is a function that keeps it from turning on again too quickly so as not to burn out your fridge.

 

If it's anything like my temperature control unit ($15 on amazon), it can specify the deviation. I have my heater / coolers set to turn on at -/+ 0.3C difference from my target.

 

I'll second the above - mine stays rock solid all the time.

Check to make sure the jumpers are positioned correctly, check what the setpoint and differential are, and make sure the probe is insulated and stuck to the side of the fermenter.

 

Oh - and as for insulating the probe and taping it to the keg, I just took a maybe 1 inch by 2 inch piece of styrofoam out of the garbage, cut a little channel out for the probe, and taped it to the fermenter. Doesn't have to be fancy.

 

oh ok cool i have the stuff to do that.

I'm not sure what jumpers or anything I looked on the manual and it doesn't say anything about it.

It just has a little dial and it's supposed to be set it and forget it I think. Factory set at 3.5 degree deferential that is not adjustable.

here is the manual for it I don't see where I can do much configuring

http://www.beveragefactory.com/images/guides/A19aat-2c.pdf

It's possible my ambient temperature gauge is also off a degree or so, but it's pretty accurate.

 

Looks like the differential is set at 3.5 F and is not changeable. So the there is a seven degree range around your set point.


Sent from my iPhone using Home Brew

 

I'd be OK with that if it's 3.5 on either side. As it stands it lets the freezer get up to about 7 degrees over before it kicks on.

I don't want to set it too low though because then it gets too cold.

I'll try the Styrofoam and see if that helps otherwise I'll just have to hope my first batch isn't affected by the swings.

 

Really??? That would keep me from ever considering that particular controller.

I keep my STC-1000 differential set at 0.5*C and it holds a temp quite nicely with the probe taped to the bucket and insulated.

 

This is how I have my probe insulated and it works quite well.

 

that an easy thing to wire up?

Seems like a decent price for it.. Wondering if it's worth the switch.