I’ve been doing this thing for about 8 months now and had some really good beers come out of it - won a homebrew “people’s choice” competition at work last week with a dark lager; pretty jazzed about that.
I haven’t paid close attention to how long it takes to chill down the wort until this last weekend. I did another batch (5gal) of dark lager and it took right at an hour with the immersion chiller running with strong flow throughout and with the kettle sitting on/in an ice bath to help speed it up. I’ve been using the IC since my second batch back in January (the first one I just sat on ice and allowed to chill on it’s own.)
My questions are these:
– Is 1 hour normal for IC chilling? I’d expect it to be in the 30-ish minute range.
– The water coming out of the IC was cold. I’d think with good heat transfer it’d be at least room temperature, it not warmer… especially at first.
– The water is coming from a tap and coming out at full flow. I’m wondering if the water isn’t spending enough time to pick up heat transfer on the way through the chiller and I should back off the pressure.
– I haven’t tried chilling the chiller before submersion.
– I picked up an immersible pump so I could recirculate ice water through the chiller. That’d save on the water bill for sure but it seems like if it’s working properly the water temp would drop over time.
in terms of time YMMV, a. in terms of the temp coming out of the cooling water, the faster the COOLING water flow the lower the COOLING water outlet temperature will be. however the faster the COOLING water flow, the faster you will get cold wort. you just use more water to do that.
so assume you leave the heat source on your wort such that it’s temperature is maintained constant your cooling water will have a Tin (tap temp) and a Tout at flow rate F1. now double your cooling flow rate. tin will not drop but tout will ( a new narrower delta t), assuming that the heat source temp is maintained.
a better example would be to have very cold fast moving cooling water, and throttle your wort flow (now source temp is not being maintained as we are trying to cool this) you could throttle your wort flow to a trickle and with fast cold cooling the wort coming out of the chiller after one pass would approach your tap temp and the outlet of the cooling water would be very close to the tap temp. if you then doubled your wort flow, the outlet of the wort will not be as cold, and the outlet of the cooling water will be warmer,
It helps to either move the wort or the chiller. I move my chiller around and I can feel the outflow pipe heat up when I do this. Takes maybe 10 minutes to get to 120f before I start recirculating ice water.
Area of the chiller. Bigger diameter and longer length are better as you chill across the metal area in contact.
Temperature differential of the wort and chilling water. You want the water as cold as possible.
Flow rate of the water. If you shut the water off it will take longer to chill. Don’t slow it down. If you go wide open you maximize #2 above.
Keep the wort moving, so it will not stratify. If you have a layer of cold wort around the chiller, you are minimizing #2 above.
You can’t chill any lower than the input water.
I have a 50 ft 1/2 in chiller. Wort is recirculated with my March pump so that it whirlpools around the chiller. Running the cooling water wide open I can chill a 10 gallon batch to 65 in a little less than 15 min in the winter when the tap water is cold. In the summer I can get to 100F fairly quick, but need to use an ice bath and pond pump if the tap water is >70F.
When I learned to agitated the chiller once it gets down to about 100F, that sped up my chilling time significantly. Definitely try that and maybe don’t have the water on full blast, you’re just wasting water and it’s not really going to make that big of a difference.
I run the cooling water through as slow as possible. The point of a chiller is to remove heat through conduction into the coil and then from the coil to the water. With this contact time is good; the longer you have the wort in contact with the coil and the coil in contact with the water (not total volume, but one specific amount eg: quart A of total) the more heat you will remove. This work till you hit you ground water temp, well close to it.
Two batches ago(middle to end of June) it took me 21 gallons to cool 6gallons of wort to pitching temp using my 50’ 3/8 coil. I did not measure my ground water temp, but I can say I use city water and we were in the middle of a heat wave (over 90 for 3 or more consecutive days). Total time was between 30-45 minutes most of which was going from 85-70.
+1 to moving the wort. I use a sanitized silicon spatula and keep stirring the wort the whole time. I get close to Tin within about 20-30 minutes. for me, in the summer this means putting the wort in the fermenter at ~80* and letting it chill the rest of the way overnight in the fridge. But I can feel the change when I put my hand on the outflow end of the IC and stir the Tout gets higher.
With my new 50’ chiller this spring, I was chilling 5.5 gallons down to 64F in 6-7 minutes. Will start brewing again in September, water will be warmer, so should be interesting how much longer it takes.
With my old 25’ chiller, it would take 12-15 minutes in the spring, 15-20 minutes in the fall.
Running slow will minimize the water used.
Running fast will minimize the time. Read my post.
Since water is cheap, I choose to minimize my time.
BTW - the water pump in you car pumps more fluid at higher RPM’s, which along with the increased ram air flow through the radiator, keeps your engine from having a thermal incident. Which is a good thing.
It sounds like you have a bad design for an immersion cooler based on what you have said (long cooling times and water coming out of IC is cold). What is the length and diameter of the tubing? Can you post a picture of your brew pot and your IC? The water coming out of my IC is steaming hot initially.
Winter cooling is about 5 minutes, considering I have to drive the hose while I’m mashing and boiling. In the summer.
In the summer(as I described) I don’t need a pump or ice bath to get to pitching temps just go clean something while I wait.
I do agree that water is cheap, but for the same cost of a decedent pump I can brew an addition 20-30gallons of beer… I’ll chose beer. Also it’s one less thing to worry about(not worrying if I have enough ice).
With my tap water in the mid 70s in the summer there is no way, no how, that I can get to a 65 pitching temp. In the winter the pond pump gets used to get down to a 45F pitching temp.
I am on city water. If you have a well that is cold, sure you can get down to ale pitching temps.