Ever since Paddy and I picked up our Robobrew last year, we haven’t given much love to the old brewing equipment that we used to cherish. So lets have a look at how to clean and maintain a copper cooling coil that’s in need of some TLC.
First and foremost, let me begin by stating that the copper cooling coils you see used in homebrewing are made out of pretty soft copper, and it’s very normal for this to bend and flex over time, and also to develop a pretty decent patina of tarnish and general muck.
When ever you use a cooling coil, you really want to ensure you rinse it off straight away. In the photo, above, you may be able to pick out some spots on the top half of the coil that weren’t properly rinsed clean, and have some dried hop and general protein etc from the wort firmly dried in place. I did rinse this little fella off after the last batch of pale we brewed with it, but clearly not very well.
To get this clean from this honestly pretty horrendous state, it’s going to need some real attention. Fear not though, if you own a coil and it’s starting to resemble something that sunk on the titanic last century, all is not lost. With a good soak in the right ratio of vinegar and water, you will loosen up a lot of the material that has dried. Now, you’re going to have to exert some real elbow grease in order to scrub clean a coil in this kind of state (I recommend getting Paddy on the case, he’s the man made of muscle - just don’t let him bend into a new and innovative shape), but it can be done, refer to the bottom half of the coil in the photo above.
To bring back that bright sheen you know and love, mix up a bucket of diluted white vinegar to the approximate ratio 180 ml white vinegar to 18-19 Ltr warm (about 6 oz white vinegar/ 5 gallons water for those in the old backward system) , and give it a good soaking (I do 1-2 hours). It’ll come out shinier than the head of a balding used car salesman. Rinse thoroughly after this, need to get all that vinegar off.
In terms of maintenance, you really just want to try and avoid getting to the point that the coil pictured had reached. Rinse immediately after every use, give a soak in the vinegar mixture listed above, and a Star San treatment only when needed.
FULL DISCLOSURE: The ratio that I use is not my own, it’s an approximation, taken from the below link. I just googled this the first time I needed to clean a copper coil and it’s never let me down: https://www.coldbreakbrewing.com/blogs/homebrewing-help/16297193-cleaning-and-sanitizing-an-immersion-chiller