Time to cool (or heat) full carboy to temp?

[mpruett]

Here's one that I couldn't find any info on while searching.

How long would it take to cool a full 5 gallon carboy from say.. 70 degrees down to 50 degrees, using a chest freezer set at 50?

The reason I'm wondering is because I brewed my second lager yesterday (hopefully the first successful one!), and after cooling the wort down to garden hose temp (probably between 65 and 70), I aerated, pitched the yeast and promptly put the carboy w/airlock in the chest freezer, which was already at 50.

What I'm curious about, is how long did it take (or is it taking?) to get to that same 50 degrees? My suspicion is that it probably took 6 hours or thereabouts, but that's not based on anything scientific- just extrapolating from other volumes of water.

 

[StunnedMonkey]

Based on my experience this weekend I think it'd take way longer than 6 hours at 50 degrees. I brewed my first lager this weekend, and chilled to 68 degrees with an immersion chiller. Rather than put it into a 50 degree chest freezer, I had my chest freezer set at 0F. I used a fermometer on the carboy to watch the temp. It went from 68 to 48 in about 4.5 hours at 0F. I then pitched at 48, and reset the freezer thermostat to 50, and left the lid open until it warmed up to that. The carboy remained at 48-50, and is still there this AM.

Did you pitch the yeast at 70?

 

[mpruett]

Yeah, mostly because I'm not going to have the time today to rack to another vessel and pitch. Plus, I broke my auto-siphon yesterday getting the wort into the fermenter, so it's pretty much stuck there for a while.

I think it was probably near 50 after 12 hrs though; the temp readout read 48 in the chest freezer. I'd think that if the carboy was significantly higher than that, the air temp in the freezer wouldn't be so low.