A hop-back is a little air-tight chamber that gets filled with fresh hops or hop plugs (sorry, pellets won't work), and gets stuck in the siphon line between the brewpot and the counter-flow wort chiller. It serves 2 purposes the hops help filter out any hotbreak that makes it into the line you get mega-armoma and flavour from the hops As for the latter of the 2, since the chamber is totally sealed, the only thing getting in or out is the really hot wort from the brewpot. Since it is so hot, it of course releases lots of aroma and some flavour characteristics from the hops and carries them with it into the chiller. Since the wort is cooled so quickly, and there is no where for the aroma to go (unlike a brewpot, where a lot of the aroma of finishing hops evaporates) you get much more out of your hops than you would with any other means.

 

Building Your Own

If you are reasonably handy with a hand drill and a soldering iron, it's pretty darned easy to build your own hop-back. All you need to do it are the items show below (in this admittedly poorly exposed picture).

Clockwise from top left are : copper pot scrubber copper plumbing fitting (2 required) pre-built strainer consisting of the above 2 items mason jar rubber gasket mason jar lid (better to have a sheet of copper) Also required, and shown elsewhere are : regular 1 litre (1 quart) mason jar screw band for above mason jar plastic tie used for computer wires 4 to 5 inch length of flexible siphon hose lead free solder

Most of the parts above are pretty straight-forward except for the fittings. I have no idea what they are called, but the picture shows it clearly enough. Our hardware store has a little wee chest of drawers for small copper fittings, and I found them by going through it. The only important thing is to make sure you get fittings that will snugly fit inside your regular 3/8 inch flexible siphon hose. I just grabbed a few different sized fittings and brought them over to the part of the store that sells the hose, and checked the size there, but you may want to bring your short 5 inch piece of hose in your pocket, just in case the store doesn't have hose.

As mentioned above, it is much better to get a small piece of sheet copper for the lid, since regular mason jar lids actually rust - especially so after drilling the heck out of them. As soon as I get a piece, I'll be making a new top for mine, but this one will do for a few batches of beer, I'm sure, before it begins to rust. If you do use sheet copper, you'll have to trace a mason jar lid onto it, and cut it out. You'll also need a gasket as shown. If you can't find a gasket, just wrap some white plumber's tape either along the edge of the sheet copper, or around the mouth of the mason jar. Either should work just fine.

The first thing we have to do is drill a couple of holes in the lid (or copper) as shown above. When doing this, placing a piece of wood under the metal will make life much easier. Go easy with the drill, and don't force it too much. It will do the work if you just let it. You don't have to be too particular about placement of the holes, just don't put them too close to the edge, nor too close to each other. I just guessed at the above holes, and they work just fine. To choose the drill bit size, I just held the bits up alongside the fittings I had, and used the one that was about the same size. Remember, though, that if you are in doubt, it's better to first drill a hole too small and then make it bigger if you must, because if you make it too big, you can't make it any smaller again.

Once you get the holes drilled, you'll want to solder the fittings in place. I don't think it matters if you push them in from the top or from the bottom, but for the record, mine are pushed in from the bottom. Not being much of an expert with a soldering iron, I just cut off about 3 or 4 inches of solder, wrapped it several times tightly around the fitting where it meets the disk, and then went to it with a flat-tipped iron. Within a minute or so I had it looking pretty decent, and even managed to impress myself somewhat. My second fitting already had the copper pot scrubber attached ( as in the picture to the left ) when I soldered it on, but I'd recommend doing the soldering first, then attaching the scrubber.

The scrubber gets attached to the fitting with a simple heavy-duty plastic electronics tie that any computer shop should have. If you are reading this, you already know someone with a computer, so it shouldn't be too difficult to track one of these things down. They differ from the plastic garbage pull ties in that they are extremely heavy-duty and break-resistant, and can't be un-done when pulled closed. First cut the elastic band out of the scrubber and remove it, then carefully weave the plastic tie in and out of the scrubber mesh along the outer edge of the flattened scrubber, slowly pulling it into a ball as you go along. You'll only need 5 or 6 weaves before you are back to the start, and can pull the tie closed. Close it most of the way, then stick the thing onto the fitting and pull it really tightly closed, and cut off any excess from the tie. You should now have something that looks more or less like the contraption below, and you are just about ready to go. All you need to do now is attach your short piece of siphon hose to the other fitting, also on the bottom side of the lid, and away you go. I couldn't find my short hose when I took this pictures, so it isn't shown here. It's used on the wort-in line to allow the wort to flow from the very bottom of the jar, back up to the top again, passing through all your wonderful hops on the way.

 

To use a hop-back, just stick it in-line between your boiling kettle and your counter-flow wort chiller, put in a half ounce or so of hops, and proceed as normal. Since I don't have a pump for my chiller, I rely on a siphon to make it go. To start the whole thing I gently suck on the far end of the chiller until the hop-back fills up with hot wort, then give one big long final suck to get the siphon going. Works like a charm!