Carboy temperature loss over time chart / graph??

[gifty74]

Brewing tonight and with the summer ground water can only get down to around 85-90F with a reasonable flow rate through my CFC. My question is, I can set my chest freezer to any temp, and I've been looking for a chart that shows temp loss from a carboy (or other 5.5gal liquid) over time, for a given temp. Does anyone have any personal experience or data?

 

[billl]

Assuming you've got an external controller if you can adjust the temp. Just tape the probe with some insulation around it right to the carboy. It will keep reading a higher temp even if the air is cold. The freezer will run until the wort itself is cooled.

I have the same issue and it takes a couple hours to get to pitching temps.

 

[kh54s10]

I don't have a chart or know how long it takes for a carboy to cool in a chamber.

But why can you not get down lower than that? Is your ground water coming from a hot spring. I use a DIY immersion chiller, two 20 ft. coils in the summer one goes in a bucket of cold water until I get the temperature down some, maybe to about 100F. I then add ice to the water and can get the wort below 70 pretty easily. Maybe 20 minutes or so. A CFC should be better.

 

[IslandLizard]

I don't have a chart or know how long it takes for a carboy to cool in a chamber.

But why can you not get down lower than that? Is your ground water coming from a hot spring. I use a DIY immersion chiller, two 20 ft. coils in the summer one goes in a bucket of cold water until I get the temperature down some, maybe to about 100F. I then add ice to the water and can get the wort below 70 pretty easily. Maybe 20 minutes or so. A CFC should be better.

I do know that placing the carboy in a tub (plastic storage tote, cooler, etc.) with cold water and ice (packs) is the quickest way. Agitation speeds things up even more. The back end of your plastic stir spoon goes through a carboy neck.

+1 on the pre-chiller method, I use a small coil in the Summer when our groundwater can't cut it.

 

[gifty74]

But why can you not get down lower than that? Is your ground water coming from a hot spring.

Ground water is ~75F here in central PA. I recirc through the chiller while whirlpool hopping and it gets knocked down to 100s fairly quickly (after resting at 170F for a while). Then I let the hops/trub settle in the middle of the kettle, and put the outlet into the carboy. Last night it chilled 125F wort to about 80F at a reasonable flow rate (5 min fill for 5.5 gal). It's a 20' counterflow, so not the highest cooling efficiency, but does the trick for me, and I like that I can run through all the while cooling and whirlpooling at the same time. I don't like running water for 30 min, that's just me. I've found no great benefit in pitching the same night, vs the next morning, so I figure just get it to 80-90F and set the chest freezer and be ready to pitch after my morning coffee. A few data points and I should be able to put together a pretty functional graph. Last night I got lucky and hit 64F on the nose by 7:30am. It's a Speidel carboy, and wort was 82F. Set chest freezer to 55F at 9:30pm, and wort was exactly 64F at 7:30am this morn. So in the future I'll probably have similar temps, minus a few in the fall/winter, and should be able to get within a degree or two of target pitch temps.