A New Breed of Prechiller!

In my limited experience of homebrewing, chilling seems to be one of the least streamlined parts of most brewers' set ups (including mine). In looking towards my ideal set-up, I've come up with a couple of potential improvements that would allow for more control over the chilling process.

1) Instead of the regular prechiller, just connect an in-line stretch of PVC to the hose going into the immersion chiller and fill it with a couple gallons of ice. Easy to make and should cut down on chilling times considerably. Construction would have to be durable, though.
2) Whirlpool the wort during chilling with a stir-plate type mechanism. They sell stir bars that are 3" by .5" and a cheap electric motor with some magnets attached shouldn't be too difficult to build. Such a mechanism would allow for much faster cooling of wort and would be easier and more effective than stirring by hand. It would be great to be able to just stick the instant-read thermometer into a swirling pot of wort and get an accurate reading.

These are my two potential innovations in chilling. Together, they should make wort chilling a breeze. I intend to try these both out when I get the time, but I would like to here comments and/or concerns about these ideas. For people who like building things (like me) this would be a fun project indeed.

Great Ideas, The PVC may work without much change to your plan, but I would think your Stir bar would need to be much bigger, heat resistant, and much more powerful magnates that can go through metal. A motor on the lid with a rod leading to a paddle might work better.

RE: prechiller....I know some people already do this but use a with a small coil of copper in a bucket with ice. I'm not sure the PVC pipe has the thermal characteristics to to remove the heat from the water as it passes through the cold pipe. The plastic might act as an insulator if anything. My guess it the first gallon or so of water that moves through the PVC pre chiller will be cooler as it passes through a pre-chilled length of PVC pipe, but subsequent gallons will not be since the continued cooling of the the pipe will be inefficient. The only way this might work would be to have a wort moving through the pipe REAL SLOW...any faster and the hot wort will warm the pipe up faster than that ice could cool it down. Maybe go with a ice/water/rocksalt mix?

RE: I think you are right that contant whirlpooling will cool the wort faster but I don't think many people will want to do this since the constant whirlpooling will disrupt the hot break settling out. Yes, you get the hot break into a cone by whirlpooling, but it settles out into a cone only after you stop whirlpooling. Here, that stir-bar will be spinning where the hot brake cone is supposed to settle and will keep that stuff spinning around in the wort. Others will probably mention the risk of hot side aeration here too, although I don't know much about that.

My thoughts...FWIW.

Good luck!

I think the hotbreak forms as a function of how quickly the wort cools. If it cools too slowly (sitting overnight) it may not form, while cooling in 15 minutes causes it to form. Once it is formed, it should fall out. So, after whirlpooling to get that wort cooled quickly, let it sit for 10 minutes and the hot break should drop out.

I have no data to back this up, just mindless theories...

Regarding the inline PVC thing, I assume you mean that it would essentially be a relatively large tubular container which you'd pack with ice cubes, and your cooling water would simply flow through the inside? That actually sounds like a pretty cool idea, and should be quite easy to make. The trickiest part would be attaching hose barbs/connections to it - if you've got the tools to drill and tap a threaded hole for a 3/8" or 1/2" NPT hose barb you'd be golden, otherwise you might have to use a lot more PVC fittings to step down from the large main pipe to a threaded connection.

broadbill said:

RE: I think you are right that contant whirlpooling will cool the wort faster but I don't think many people will want to do this since the constant whirlpooling will disrupt the hot break settling out. Yes, you get the hot break into a cone by whirlpooling, but it settles out into a cone only after you stop whirlpooling. Here, that stir-bar will be spinning where the hot brake cone is supposed to settle and will keep that stuff spinning around in the wort.

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I think what you mean to say is "cold break" - hot break occurs during the boil, cold break is what you get while chilling. And yes, keeping the stirrer going would prevent settling, obviously, but there's no reason you couldn't simply shut off the stirrer after chilling was complete and give it some time to settle before transferring.

Though, I think the problem of using a magnetic stirrer in a metal pot is a big one. Not to mention, you'd have to fab up some kind of crazy stirrer that was sturdy enough to set a huge pot of boiling wort on - and it would be less desirable as you'd have to move the pot of boiling wort from the burner to the stirrer instead of chilling in place. And, it wouldn't work for keggles, which many people use, since the bottom is far from flat.

I think you'd be much better off stirring the wort from above with an electric motor. I've heard of someone doing this with an electric drill rigged to a wine degassing stirrer, all rigged to the lid for hands-free operation.

I can respect the desire to create an "ice capsule" inline with your hose because the real beneifit here is using tap water pressure to drive it through the chiller. The easy alternative is a $20 pond pump that you would immerse in any old container you had; a bucket, rubbermaid bin, cooler, etc. You would then not have to store a large dedicated ice "tube".

Let's talk about potential contruction. You'd want it to hold at least 20 pounds of ice and since it will be sealed, you don't want to have to keep loading it. Maybe 3 foot section of 6" PVC (not easy to come by). One end would just be capped. Drill a hole and cement in a 1/2" male connector to which you'd put either a hose barb or hose adapter on. You'd also want to put some kind of course mesh down on that end to keep a melted piece of ice from plugging the output. On the other end, you'd want to install female adapter. This end would get plugged after filling with ice. A similar hose attachement would go on this end. If you price out 6" pvc parts, even if you get the pipe section free, you'll find the $20 pond pump is a total bargain.

Using icewater to chill with means you can just stir the wort with a spoon. It will take under 10 minutes to chill so a stirring motor would be kinda frivilous.

Funkenjaeger said:

Regarding the inline PVC thing, I assume you mean that it would essentially be a relatively large tubular container which you'd pack with ice cubes, and your cooling water would simply flow through the inside? That actually sounds like a pretty cool idea, and should be quite easy to make. The trickiest part would be attaching hose barbs/connections to it - if you've got the tools to drill and tap a threaded hole for a 3/8" or 1/2" NPT hose barb you'd be golden, otherwise you might have to use a lot more PVC fittings to step down from the large main pipe to a threaded connection.

Click to expand...

Precisely

Funkenjaeger said:

I think you'd be much better off stirring the wort from above with an electric motor. I've heard of someone doing this with an electric drill rigged to a wine degassing stirrer, all rigged to the lid for hands-free operation.

Click to expand...

I thought about the stir from above method but I settled on the stir bar because some stir-bar company website said that one little stir-bar could stir some huge amount of liquid and was safe to use in heat. It sounds like a stretch of the truth, though, so maybe drill rig you mention would be more foolproof.

Bobby_M said:

Let's talk about potential contruction. You'd want it to hold at least 20 pounds of ice and since it will be sealed, you don't want to have to keep loading it. Maybe 3 foot section of 6" PVC (not easy to come by). One end would just be capped. Drill a hole and cement in a 1/2" male connector to which you'd put either a hose barb or hose adapter on. You'd also want to put some kind of course mesh down on that end to keep a melted piece of ice from plugging the output. On the other end, you'd want to install female adapter. This end would get plugged after filling with ice. A similar hose attachement would go on this end. If you price out 6" pvc parts, even if you get the pipe section free, you'll find the $20 pond pump is a total bargain.

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Good point. I hadn't considered how large the ice tube would have to be to hold enough ice, partly since I didn't have a feel for how much ice it would take to cool a batch. 6"x3' of PVC is indeed a bit ridiculous, even with cost considerations aside.

I fully intend to switch to a submersible pump before long, I just haven't decided what one to get. Everyone seems intent on using the full-fledged sump pumps, but somehow a huge pump with a 1" outlet seems a bit overkill for pumping water through 3/8"ODx1/4"ID copper tubing, and the 150-300GPH fountain pumps (which cost half as much) seem appropriate - but I haven't taken the plunge, as I'd like to hear from someone who's used that type of pump with good results.

Bobby_M said:

I can respect the desire to create an "ice capsule" inline with your hose because the real beneifit here is using tap water pressure to drive it through the chiller. The easy alternative is a $20 pond pump that you would immerse in any old container you had; a bucket, rubbermaid bin, cooler, etc. You would then not have to store a large dedicated ice "tube".

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I don't think the pond pump would move nearly as much water as a hose connected to a faucet. But I've not looked into the pond pump area of commerce, so I'm only speculating.

Bobby_M said:

Let's talk about potential contruction. You'd want it to hold at least 20 pounds of ice and since it will be sealed, you don't want to have to keep loading it. Maybe 3 foot section of 6" PVC (not easy to come by).

Click to expand...

I was thinking two gallons of ice, which is about 16 lbs. I'm just curious about how you came up with 20 lbs? I came with 2 gallons because I heard Jamil say that 1 gallon of ice can cool 5 gallons of near-boiling wort to 80 degrees F if you just throw it in. So I figured another gallon should be sufficient to get it down to 60F.
I'm pretty sure my local home depot can cover all my PVC needs. Whenever I've needed anything PVC, they've had it.

Knowing how much ice you'd need is just speculation. It's affected by the tap water temp coming in and the flow rate. If you melt all the ice before the wort is at your desired temp, you'd have to stop, open it up (spilling all kinds of water) and repack with ice.

Pumps: Pond pumps are enough but you'll need something like 300-600gph. I know it sounds like a lot but that rating is with no fittings/tubing on the outlet and no head pressure. If your icewater bin is on the floor and the IC is up in your pot 4 feet higher, that's quite a bit of head. You're also running it through a highly resistive coil. Anway, a 100gph pump in this application would be lucky to hit 10 GPH.

The absolute cheapest compromise I've used in the past is putting your bottling bucket up on a 6' ladder and plumbing the spigot to the IC and put your icewater in there. At least in that configuration you can replenish the ice easily if necessary.

It's important to also make sure you need prechilling in the first place. If you tap temp is 65F or lower, you're golden.

Bobby_M said:

It's important to also make sure you need prechilling in the first place. If you tap temp is 65F or lower, you're golden.

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No matter what temperature your tap water, the cooling process will go faster if the water is colder. 32 F water will chill wort much faster than 65 F water. The water going through an ice bath will be 32 F, but if the tap water is hot to begin with, more ice will be needed to maintain that temp. But I agree that this is entirely unnecessary for many people.

There's the law of diminishing returns though. I'd never go through the effort of making this device and packing it with ice (not free) on every batch just to shave 10 minutes off my chill time. I'd agree that 65F is borderline. It would take a while to get to 75f. Once you get to about 60f and under, you'll get there pretty quickly. I know, it's only $3-4 worth of ice but it would be like 10% of my batch cost and I'll avoid it if I can. Since the beginning of November, my tap has been in the mid 50's F which is plenty cold.

I'm not trying to say that there is anything wrong with chilling another way. If my tap water were in the 50's I'd probably still build this just because I like to tinker. I wouldn't spend $3-4 on ice either. I'll just make it in my freezer (of course there is some electricity cost). If people are happy with the way they're chilling, they need not pay attention to this thread at all. Thanks for the input, I appreciate it.