CFC only getting wort down to 95

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cpbergie

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Im using a keggle, pump, 25 ft copper pre-chiller, and a CFC when i brew, and i still only get the wort down to about 95. I live in SoCal so my hose water is pretty warm (85) but i thought i would be able to get the temp lower than that. I submerge the pre-chiller in an ice water bath, but it doesnt seem to help as much as i had thought.

Should i have the hose water on full or throttle it back for more contact time in the pre-chiller? I can also reduce the flow of the wort in the CFC from the pump but still only got down to 95.

Whats the best way?
 
Some options

1) Switch your pre-chiller to a post-chiller. Run the outlet from the CFC through the coil submersed in an ice bath. This WILL work better than using it as a pre-chiller. The slower the wort flow, the cooler it will be.

2) Throttle the wort flow through the chiller. The more contact time, the more heat exchanged. BUT - see note below.

3) Get a submersible pump and pump ice cold water through the CFC. I just bought one and am looking forward to trying this on Mon when I brew next. I may do a dry run this weekend to see how it works.

Should i have the hose water on full or throttle it back for more contact time in the pre-chiller? I can also reduce the flow of the wort in the CFC from the pump but still only got down to 95.
This is the problem with a pre-chiller. It needs a throttled flow to chill the cooling water, but you want the cooling water flowing faster through the CFC to effectively chill the wort. These are at odds with each other. This is why I advocated #1.
 
I would recommend using a low flow through the pre-chiller and CFC. This gives the water more contact time with both the ice bath and the hot wort in your CFC.

I don't have a CFC, but I do use a pre-chiller for my immersion system. I crudely balance the flow by feeling the tube temps on the inlet and outlet of my immersion chiller.

I try to get the inlet as cold as possible by adjusting the flow and double check to make sure the outlet is warmer. When the differential becomes too small to detect, my wort is usually 70 or below.

If you have the supply water on high, there might not be enough time for thermal transfer from the wort to the water. I remember reading something that the additional turbulence or friction caused by high flow can be detrimental to cooling.

Anyway, I hope this helps some,

-Matt
 
With a CFC you have to have the cooling water flowing as fast as possible. That is an absolute fact, you can look it up. The "contact time" doesn't mean anything. You need to get rid of the heat as fast as possible.

The wort flow is more of a trial and error, decreasing it won't gurantee better results.

I'd go with Lil sparky and use the 25ft of copper as a post chiller. I'd first measure the temperature of the wort after coming out of the CFC. The final wort temperature should be near the starting cooling water temperature. If there is a large gap make sure the cooling water flow is as fast as possible, then play with the wort flow until you get the temperature down.
 
The pump does give you the ability to run the post chiller. It will certainly be better when what you have. Make sure you run boiling wort through both chillers to sanitize. At least that's what I do.
 
Using some salt in the pre chiller bucket should lower that temp a few degrees. It should be very little water and mostly Ice. Just enough water so it's like a half thawed slushy.

The submersible pump is probably your best bet if your tap water is 85 degrees. So that you can recirculate Ice water.
 
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