Boil Kettle Upgrade: Whirlpool Port

During a recent brew day, I discovered what a big difference recirculating hot wort through my chiller and back into the boil kettle could make, on both chilling time and making sure my chiller was properly sanitized. While it's not a huge concern, just dropping the hose in the top of the boil kettle does leave me open to accidentally spraying wort everywhere if the hose falls out, or I trip over it, or whatever. Additionally, if I'm going to recirculate, I might as well get the benefits of whirlpooling too, right? So I decided to add a whirlpool port to my boil kettle.

Step bit and knockout punch.

I already own the tools that make this process difficult and expensive, because they were required for my brewery build (a clone of The Electric Brewery) in the first place. Specifically, they are a step bit (Greenlee 36414 Multi Hole Step Bit, 1-3/8") and a 13/16" round punch (Greenlee 730BB-13/16 Standard Round Knockout Punch). I would essentially just be putting in one more port, almost exactly like the one in my hot liquor tank. I had some extra o-rings and a set of washers lying around too, so I only had to order a few stainless fittings.

I went over to Bargain Fittings, who have great prices and a nice $5 flat shipping rate, and selected a 3-piece ball valve, 90 degree 1/2" NPT to 1/2" compression, nipple close, 1/2" NPT locknut, 1/2" NPT coupling, and a 5" piece of stainless tubing. They shipped and arrived promptly.

From left to right: 5" 1/2" OD tubing, 90 degree 1/2" MPT to 1/2" compression, 1/2" NPT coupler, 7/8" ID 1-3/8" OD washer, 1/2" NPT nipple close, 1-1/8" ID 1-5/8" OD washer, 211 Silicone O-Ring 70A Durometer 13/16" ID 1-1/16" OD 1/8" Width, 1/2" NPT locknut, 3-piece ball valve, 1/2" MPT quick disconnect.

One other thing you need is PTFE (Teflon) thread seal tape. Without it, you will not be able to get a seal and you risk galling your threads. There are plenty of good videos on YouTube about how to use PTFE tape. I watched this one a long time ago, and as a result I know how to use PTFE tape, and I always hear "PTFE tape" in the accent of the guy in the video. I just try to remember to hold the threaded object in my left hand and then go over and around with the tape in my right hand. This makes sure that when you screw in the threads, it doesn't undo the tape. Here I've taped up the quick disconnect and threaded it into the ball valve.

Time to drill (another) hole in my kettle! It's a good idea to make a small dimple if you can with a nail or other tool so that the step bit won't wander around. I didn't have a nail, so I just went to town with the step bit, pushing the kettle up against the wall so I could use a lot of force. I had debated extensively with myself where to place the port, in terms of height. After doing some reading, I decided to put it right about at the 5 gallon level. I wanted to be able to use it if I was only doing a 5-gallon batch, but I didn't want it too low, to ensure that the wort would mix enough during cooling.

This is where the whirlpool port will be located.

Finally starting to get some purchase.

A hole big enough to insert the punch!

You will want to be careful with the step bit. Cutting oil will help keep things lubricated and prevent the bit from getting too hot. You may also want protective eyewear, as metal shards may get thrown all over the place. Once I had a hole big enough, I fed the punch through, and got ready to tighten that bad boy down.

Knockout punch centered and tightened most of the way down.

These punches are expensive but they make a really clean cut.

Next, I was able to feed the nipple close in from the outside. This is actually important—if you feed it from inside, you will wind up with too much slack on the inside. Some of the threads that would wind up on the inside need to wind up under the o-ring and locknut on the outside, so that all the connections can be tight, including the one holding the o-ring up against the kettle wall. I applied PTFE tape to both sides of the nipple, fed it in from the outside, and twisted the smaller washer and coupling on the inside. Once there, I put the o-ring on the outside, placed the larger washer around it, and tightened down the locknut, making sure the grooved side was against the kettle wall.

Tight fit holding this to the kettle.

Then I was able to fasten the ball valve and the compression fitting to the outside and inside of the kettle, respectively. With a 3-piece ball valve, you don't need to get it perfectly aligned. Just get it to the closest 90 degrees, and then you can disassemble the valve and re-position the handle on top (or wherever you want it). Crank everything down extremely tight—the large washer and groove in the locknut will prevent you from overcompressing the o-ring. I borrowed a conduit bender from a friend, and with some fancy clamping and abuse of a screwdriver, was able to bend the stainless tubing to better match the curve of the kettle wall. The clamp and the screwdriver both deformed the ends of the tubing a bit so that they wouldn't fit into the compression fitting, but I just cut off about half a centimeter of the end of the tubing on the side where I used the screwdriver and then it fit again. I inserted the tubing into the compression fitting, tightened it down by hand, and then used a wrench to get another turn or so to swage the ferrules and seal the fitting.

Bent tubing.

Taking off half a centimeter or so from the (visibly) deformed end.

Completed whirlpool port from above.

Once the port was installed I decided to test it while also recirculating some hot PBW through my wort pump and boil kettle. There was some gunk under my heating element and temperature probe that I would probably be better of without. This would also give me a chance to see what kind of whirlpool I could get going.

It's alive!

I left the recirculation going during dinner and came back to check on it afterward. The results were impressive: the PBW had pulled a lot of the gunk out of all sorts of nooks and crannies, and the whirlpool had deposited it all on the bottom of the kettle, right in the middle. Hopefully during brew days that will be break material and hop debris that would otherwise have wound up in my fermentors!